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RADIO  BROADCAST 

Volume  III 

MAY,  1923,  to  OCTOBER,  1923 
BETTER  RADIO 


GARDEN  CITY  NEW  YORK 

DOUBLEDAY,  PAGE  &  COMPANY 

1923 


Copyright,  1923,  by 
DOUBLEDAY,  PAGE  &  COMPANY 


INDEX 


(*Illustrated  Articles.    Editorials  in  Italics) 


PAGE 


ACCURATE  Measurement  of.  Signals,  The  97 
*Adding  Two  Steps  to  Your  Aeriola 

Senior  (Jacques  H.  Herts)   52 

Adventures  in  Radio: 

When  Messina  was  Destroyed   303 

*Adventures  on  an  American  Yacht  in  Mexico 

(A.  Henry)   149 

All  Boy  Scouts,  Attention!   66,166,335 

*Among  the  "Hams":   65 

Amateurs  Taking  the  Code  Test  at  the 

Hotel  Pennsylvania,  New  York. ...  65 
Officers  and  Members  of  the  Mil- 
waukee Amateurs'  Radio  Club   65 

2nd  District  Amateurs'  1923  Banquet 
at  the  Hotel  Pennsylvania,  The. ...  64 

*Among  Our  Authors  264,356,442,534 

As  the  Radio  Corporation  Sees  the  Patent 

Situation   4 

Atchison,  Kansas  Takes  Control  of  Radio ....  12 

*"DEST  Battery  Connections  for  the  Circuit 
-D    You  Use,  The    (Edward  Lindley 

Bowles)   123 

*Better  Broadcast  Receiver,  A  (Arthur  L. 

Munzig)   477 

Bit  About  Books,  A   165 

*Bit   About   Myself,   A    ("Roxie"— S.  L. 

Rothafel)    459 

Books: 

Bit  About  Books,  A   165 

Boosting  the  Box-Office  Receipts  at  the  Opera ....  10 
Boy  Scouts: 

All  Boy  Scouts  Attention!   66,166,335 

Boy  Scouts'  Receiving  Contest   240 

Help  the  Boy  Scout  With  His  Radio. .  .  99 
Broadcast  Central  Comprising  WJZ  and  WJY.  274 

Broadcast  Receiving  Contest   73,164 

*Broadcasters  in  New  York,  Paris,  and  Los 

Angeles   429 

Broadcasting : 

Broadcast  Receiving  Contest   73,164 

Commercial  Broadcasting  In  Germany.  100 
Effect  of  Broadcasting  on  the  Churches, 

The   273 

Effect  of  Broadcasting  on  Sermons  and 

Speeches,  The   6 

*Giving  the  Public  a  Light-Socket 
Broadcasting     Service  (William 

Harris,  Jr.)   465 

*Is  Short- Wave  Relaying  a  Step  To- 
ward     National  Broadcasting? 

(W.  W.  Rodgers)   119 

Is  Wired  Wireless  the  Future  of  Broad- 
casting?  457 

New  Wavelengths  for  Class  B  Stations  167 

Ocean  to  Ocean  Broadcasting   447 

*Supplying  Broadcasts  Like  Gas  or 

Electricity  (Grayson  L.  Kirk)   35 

"Teaching  School  from  a  Broadcasting 

Station  (Lloyd  Jacquet)   331 

What  is  the  Range  of  a  Broadcasting 
Station?   11 


PAGE 


Will  the  Composer  Pay  for  Broad- 
casting?   271 

Will  the  Entire  Nation  Listen  to  the 
Next  President's  Inaugural  Address?  13 
Broadcasting  Stations: 

Broadcast  Central  Comprising  WJZ 
and  WJY   274 

*Broadcasters  in  New  York,  Paris,  and 
Los  Angeles   429 

*Have  You  Heard  These  Stations  Yet?  33 

*Highlights  in  the  History  of  WDAP 
(J.  Elliott  Jenkins)   411 

*New  Station  at  Washington,  D.  C, 
A  (Pierre  Boucheron)   494 

Revised  List  of  U.  S.  and  Canadian 
Broadcasting  Stations   78 

Supplemental  List  of  Broadcasting 
Stations  in  the  U.  S.,  March  19,  to 
April  20,  1923   174 

Supplemental  List  of  Broadcasting 
Stations  in  the  United  States,  April 
21  to  May  17,  Inclusive   260 

Supplemental  List  of  Broadcasting 
Stations  in  the  United  States,  May 
18  to  June  15,  Inclusive   352 

Supplemental  List  of  Broadcasting 
Stations  in  the  United  States, 
June  16,  to  July  13,  Inclusive   438 

Supplemental  List  of  Broadcasting 
Stations  in  the  United  States 
Licensed  from  July  14  to  August  7, 
Inclusive   523 

*With  the  Broadcasters   135 

Buying  Sets  on  the  Installment  Plan   269 

CHINA: 
Radio  Sets  Are  Contraband  in 

China   14 

*Choosing  Your  Regenerative  Circuit  (Paul 

F.  Godley)   155 

Code: 

*Learning  the  Code  (William  Harris, 

Jr.)   113 

*  Radio  Code  with    Eleven  Million 

Variations,  A  (S.  R.  Winters)   62 

Commercial  Broadcasting  in  Germany.  100 
*Concerts  for  All  in  a  Veterans'  Hospital 

(J.  Townsend  Bradley)   147 

Condensers: 

*What   You  Should   Know  About 

Condensers  430,510 

*Confessions  of  an  Unmade  Man  (R.  O. 

Jasperson)   20 

Contests: 

All  Boy  Scouts  Attention!  66,166,335 

Broadcast  Receiving  Contest!  73,164 

*Crystal  Receivers  are  Well  Worth  While 
(Zeh  Bouck)   319 

T\EAF  Ears  Hear  Again   362 

LJ  De  Forest  Company  Beaten  by  the  Westing- 
house  Company   452 


INDEX— Continued 


Demand  for  Educational  Radio,  A  Big   94 

*Dry  Cells  and  UV-199's  (E.  E.  Horine)   247 

*Dry-Cell  Tube  Loop  Set  for  Local  Reception, 

A  (Alex  V.  Poison)   288 

TpFFECT  of  Broadcasting  on  the  Churches, 

Hi  The   273 

Effect  of  Broadcasting  on  Sermons  and  Speeches, 

'The   6 

*Eighteen  Years  of  Amateur  Radio  (George 

E.  Burghard)   291 

Electron  and  its  Discoverer.  The   181 

England: 

Radio  an  Auto  Accessory  in  Jolly  Old 

England   364 

*T7TVE-TUBE  Receiver  that  "Delivers  the 

r  Goods".  A  (E.  D.  Harrington)   234 

"Frate  Sole"  Is  Carried  Across  Continent 

to  Composer' s  First  Instructor   366 

GERMANY: 
Commercial     Broadcasting  in 

Germany   100 

*Giving  the  Public  a  Light-Socket  Broadcast- 
ing Service  (William  Harris,  Jr.)   465 

Good  News  for  Our  Readers   281 

*Grid,  The — Questions  &  Answers 

Adapting  Your  3-Circuit  Receiver  to 

the  New  Wavelengths   435 

A.  C.  For  Receiving  Filaments   168 

Amplifying  Phonograph  Music   532 

Antenna  Corrosion  and  Resistance.-.  .  436 

Artificial  Strays   86 

Audio  Amplifying  Circuits   256 

Farm  Lighting  Plants  and  Radio   258 

"Fliwer"  Set,  The   258 

Head-Sets  and  Resistance   170 

Interference  and  Fading  Caused  by  a 

Near-by  Set   350 

Loops   168 

Loops,  Crystal  Detectors,  and  Loud- 
Talkers    174 

Multi-layer  Coils  and  Induction   256 

Operating  Loud-Speakers  at  a  Distance  79 

"Peanut  Tube,"  The   172 

Polarity   530 

Small  vs  Large  Wire  in  Receiving  Sets  172 
Substituting  Loops  on  Standard  Re- 
ceivers  436 

Summer  Receiving  Conditions  and  the 

Ideal  Set   350 

Three-Circuit  Layout  With  Amplifier, 

A   528 

Trouble  with  a  Four-Step  Amplifier .  .  530 

Tuned  Circuits   79 

Tuned  Plate  Circuit,  A   526 

Winding  Spider- Web  Coils   528 

*Grimes  Circuit  with  Outdoor  Antenna  and 

Counterpoise,  The  (Herbert  E.  Dill)   314 

*"TTAM "  Set  of  an  Old  Ship  Operator, 

ii  The  (Zeh  Bouck)   23 

*Have  You  Heard  These  Stations  Yet?   33 

CKAC,  Montreal,  Can   33 

WGR,  Buffalo,  N.  Y   34 

WGY,  Schenectady,  N.  Y   34 

Hearing  North  America  (Abbye  M.  White) .  .  421 

Help  the  Boy  Scout  with  His  Radio   99 

♦Highlights  in  the  History  of  WDAP  (J. 

Elliott  Jenkins)   411 

*Home-Made  Amplifier  for  Any  Receiver,  A 

(Zeh  Bouck)   230 

*Home-Made  Three-Tube  Outfit,  A  (L.  Reith)  486 


PAGE 


Hoodwinking  the  Lisleners-In   93 

*How  Vacuum  Tubes  Are  Made  (W.  W. 
Rodgers)   397 

*TN  THE  R.B.  Lab   520 

I       *Building  Your  Own  Laboratory   522 

*Making  Your  Grid-Leaks   521 

*Playing  with  the  Grimes  Circuit ....  520 

*In  the  Wake  of  the  Contest  Winners   477 

*In  Touch  with  the  World  from  the  Arctic 

(F.  Burnham  McLeary)   283 

*In    Tune    With    the    Infinite    (Eric  G. 

Shalkhauser)   417 

Increased  Speed  of  Radio  Traffic   100 

Interdepartmental  Radio  Advisory  Committee, 

The   278 

International  Law  and  the  Sea-Going  Tele- 
grapher (Claude  Cathcart  Levin)   159 

Inverse  Duplex: 

*Grimes  Circuit  with  Outdoor  Antenna 
and  Counterpoise,  The  (Herbert  E. 

Dill)   314 

*Using  the  "  Inverse  Duplex  "  with  the 
Various  Kinds  of  Tubes  (David  H. 

Grimes)   197 

*Is  Short-Wave  Relaying  a  Step  Toward 
National  Broadcasting  Stations?  (W.  W. 

Rodgers)   119 

7s  Wired  Wireless  the  Future  of  Broadcasting?  457 

LEARNING  the  Code  (William  Harris,  Jr.)  113 

*Leviathan  Breaks  Some  Records,  The ....  454 
*Little  Foresight  and  a  Big  Success,  A  (Alfred 

M.  Caddell)   406 

*Loop  Receiver  in  the  Tropics,  A  (Charles  T. 

Whitefield)   132 

*1\  /TAKING  Radio  Your  Business  (Carl 

1V1  Dreher)   190 

*Man  Who  Built  a  Set  He  has  Never  Seen,  A 

(Alfred  M.  Caddell)   128 

*Man  Who  Knew  Lincoln,  A   455 

*March  of  Radio,  The  (J.  H.  M.) 


3,91,179,269,359,447 


Marconi  Making  Progress  with  His  Short  Waves  363 
♦Millionaire's  Cruise  on  an  Operator's  Pay,  A 

(A.  Henry)   222 

More  Injunctions  for  the  Broadcasters   180 

Music  Publishers  With  Vision   270 

NEIGHBOR  at  Three  Thousand  Miles,  A 
(Richard  Bartholomew)   305 

*"Neutrodyne"     Receiving    System,  The 

(Kimball  H.  Stark)   38 

*New  Equipment: 

Audiophone  Jr.,  The   176 

Broadcast  Receiver  Employing  the 
Neutrodyne  Principle,  A  (Mortimer 

Radio  Corp'n)   524 

Burgess  B  Battery   354 

CR-12(A.  H.  Grebe)   440 

Cardwell  Variable  Condenser   354 

Cutler-Hammer  Co.  Standard  Rheo- 
stat 354 
Durable  UV-199  Socket .' '. '. '. 262 
Everready  "Three"  Radio  Battery 

(National  Carbon  Co.)   524 

Filament  Lighting  from  a  Lamp  Socket 
(Simplex    Electrical  Laboratories, 

Inc.)   526 

For  Cutting  Out  Interference  (Malone- 

Lemmon)   440 

Friction-Contact  Variocoupler 

(Pearlco)   440 


INDEX— Continued 


PAGE  PAGE 

....  262     Radio  Repays  its  Genius   279 

....  262     Radio  Sets  are  Contraband  in  China   14 

....  88     Receiving  Contest  Winners   416 

....  354  *Recent  Broadcasters  in  New  York  Studios  (3 

The  176        photos)   246 

....  88     *Reception  de  Luxe  (A.  R.  Boscow)   324 

....  262  *Reducing  the  Guesswork  in  Tuning  (J.  H. 

....  176        Dellinger)   241 

....  176  *Regenerative  Radio-Frequency  Combination, 

  354        A  New  (Roger  A.  Weaver)   346 

Mfg.  Revised  List  of  U.  S.  and  Canadian  Broadcast- 

  524        ing  Stations   78 

  88  Rheostats  for  the  Tubes  You  Use  (Zeh  Bouck)  496 


G.  E.  Portable  Receiver  

McNeary  Radio  Scalometer  

Music  Master,  The  

New  Holtzer-Cabot  Phones  

New  Pacent  Variable  Condenser, 

Pacent  Rheostat,  The  

"Paragon"  Stage  Control  Switch 
Paragon  Tuned  R.  F.  Amplifier. 

Pathe  Loud  Speaker,  The  

Post  Electric  Soldering  Iron. .  .  . 
R.  M.  C.  Variocoupler  (Radio 

Co.)  '.  

Socket  for  the  WD-11,  A  


Sonochorde,  The   88 

Symphony  Receiver,   The  (Kellogg 

Switchboard  &  Supply)   440 

Tuned  R.  F.  Transformer  (Workrite 

Mfg.  Co.)   524 

Two-In-One  Socket  (Alden-Napier) .  .  440 
Vernier  Variometer,  A  (National  Chel- 
sea Radio  Corporation)   524 

*New  Station  at  Washington,  D.  C,  A  (Pierre 

Boucheron)   494 

New  Station  for  Sweden,  A   100 

New  Super-Cable   456 

New  Wavelengths  for  Class  B  Stations   167 

/~\CEAN  to  Ocean  Broadcasting   447 

^  Old  Radio  Company  Changes  Hands,  An  189 
*Operating  a  Loud  Speaker  on  One  Tube, 

Without  Batteries  (Walter  Van  B.  Roberts)  108 

Opportunity,  An   189 

Outdoor  Experimenting  in  Vacation-Time   91 

PATENTS: 
As  the  Radio  Corportion  Sees  the 

Patent  Situation   4 

*Protecting  Your  Invention  (Roger 

Sherman  Hoar)   136 

Putting  Your  Patent  Across  (Roger 

Sherman  Hoar)   205 

*What   Can  Be  Patented?  (Roger 

Sherman  Hoar)   55 

*Portable  Set  for  Lonely  Hotel  Hours,  A 

(J.  T.  N.)   219 

*Porto  Rico  Fan  Wins  "How  Far?"  Contest  304 

Possibility  of  Re-Broadcasting,  The   187 

*Powel  Crosley,  Jr. — "The  Henry  Ford  of 

Radio"  (Alvin  R.  Plough)   323 

*Practical  Super-Heterodyne  with  199's,  A 

(Walter  Van  B.  Roberts)   340 

Preparing  for  Long  Distance   361 

President  Harding  Over  Wire  and  Radio   359 

Private  Radiophone  Communication   367 

Protecting  Our  Readers   15 

*Protecting  Your  Invention  (Roger  Sherman 

Hoar)   136 

Putting  Your  Patent  Across  (Roger  Sherman 
Hoar)   205 

JDADIO  an  Auto  Accessory  in  Jolly  Old 

I*- England   364 

*Radio  Angling  and  Fisherman's  Luck  (H.  F. 

Huse)   316 

Radio  As  a  Rent  Inducement  (Allison  Euray)  22 

Radio  Blind  Spot,  A   454 

*Radio  Broadcast  Central  (Pierre  Boucheron)  254 
*Radio  Code  with  Eleven  Million  Variations, 

A  (S.  R.  Winters)   62 

*R.  F.  Amplification  Without  Distortion  or 

Reradiation  (Edward  Lindley  Bowles)   214 

*Radio  in  Summer  Camps  (Elon  Jessup)   102 

*Radio  Is  Expensive  for  the  Married  Man 

Robert  Oliver)   202 


SOS  in  the   Jungle  of  Indo-China,  An 
(Leland  L.  Smith)   42 

*Search  for  a  Telephone  as  Sensitive  as  the 

Ear,  A  (George  B.  Crouse)   142 

Secretary  Hoover  Acts   277 

*" Selling"  the  Public  on  Better  City  Govern- 
ment (J.  L.  Simpson)   299 

Service  Is  Necessary   367 

*Set  the  Boy  and  His  Dad  Made,  The  (Arthur 

N.  King)   210 

*Set  with  a  Tuned  R.  F.  Amplifier,  A,  (J.  W. 

Denning)   484 

*Set  You'll  Like  to  Make,  A  (Frank  Nelem)  480 
*Set-Backs  and  Come-Backs  at  6KW  (Frank 

H.  Jones)   368 

*Sets  for  the  Great  Outdoors  (A.  Henry)   336 

Simplified  Receiving  Sets   449 

*Single-Tube  Loop  Set  in  a  Brief-Case,  A 

(Walter  VanB.  Roberts)   16 

*Six-Inch    Dry    Cells   and    WD-11  Tubes 

(E.  E.  Horine)   74 

Size  of  Radio  Audiences,  The   451 

*Soldering  Your  Own  (W.  S.  Standiford)   161 

*Some  Notes  on  Tuned  Circuits  (M.  B.  Sleeper)  404 
*Some  Pictures  the  Contest  Brought  In  (4 

pictures  with  captions)   492 

Still  Trouble  from  Interference?   360 

*Stormy  P.  M.  at  Alice's,  A  (Willard  Wilson)  112 
Summary  of  Receiving  Contest  Entries  Ar- 
ranged in  Order  of  Mileages   489 

Sunrise  and  Sunset  Barrier  to  Signals,  The  8 
Super-Heterodyne : 

*Practical  Super-Heterodyne  with  199's 

(Walter  VanB.  Roberts)   340 

Supplemental  List  of  Broadcasting  Stations  in 

the  U.  S.  March  19  to  April  20  Inclusive ...  174 
Supplemental  List  of  Broadcasting  Stations  in 
the  United  States  April  21  to  May  17, 

Inclusive.. .  .*   260 

Supplemental  List  of  Broadcasting  Stations  in 
the  United  States  May  18  to  June  15, 

Inclusive   352 

Supplemental  List  of  Broadcasting  Stations 
in  the  United  States,  June  16  to  July  13, 

Inclusive   438 

Supplemental  List  of  Broadcasting  Stations  in 
the  United  States  Licensed  from  July  14  to 

August  7,  Inclusive   523 

*Supplying  Broadcasts  Like  Gas  or  Electricity 

(Grayson  L.  Kirk)   35 

Sweden: 

New  Station  for  Sweden,  A   100 

TABLET  Dedicated   to  the  Radio  Con- 
gregation, A   332 

Teaching  School  from  a  Broadcasting  Station 

(Lloyd  Jacquet)   331 

Telephone  Company' s  Part  in  This  Work,  The  448 
*10,000  Miles  of  Radio  Lectures  in  China 
(C.  H.  Robertson)   382 


INDEX — Continued 


*Thoriated  Tungsten  Filament,  The  (W.  C. 

White)   375 

Transmitting  and  Receiving  with  the  Same 

One-Tube  Set  (Frederic  W.  Procter)   29 

Transmitting  Standard  Wavelengths  for  Cali- 
brating Sets   9 

Tuning  Troubles  of  Messrs.  Gallagher  and 

Sh^an  (A.  G.  Clark)   28 

Twelve  More  Men  Owe  Their  Lives  to  Radio. .  .  14 

T  T.  S.  HEALTH  SERVICE  Functioning  by 

U  Radio,  The   280 

♦Unloading  the  Mail  from  the  Transatlantic 

Liners  (M.  G.  Carter)   311 

*Using  the  "Inverse  Duplex"  With  Various 

Kinds  of  Tubes  (David  H.  Grimes)   197 

VARIOUS  Sorts  and  Sizes,  All  Home-Made 

(4  photos  with  captions)   490 

Volstead  in  the  Air   179 

WEAF'S  New  Home  (2  photos)   239 

*  Wanted :  A  Desert  Island !   391 

Wavelength  or  Frequency?   183 

Weather  Forecasts   189 

V/esl  Coast  to  Have  a  New  Station   280 

*What  Balloon  Racers  Did  with  Receiving  Sets  507 
*What  Can  Be  Patented?  (Roger  Sherman 

Hoar)   55 

What  is  the  Range  of  a  Broadcasting  Station?  11 

What  Our  Readers  Write  Us   517 

What  Radio  Broadcast  Is  Trying  to  Do   3 

*What  Radio  Holds  for  Boy  Scouts  (Arthur  H. 

Lynch)   251 

*What  You  Should  Know  About  Condensers 

(Allen  D.  Cardwell)  430,510 

When  Messina  was  Destroyed   303 

*When  the  Bug  Bit  in  Samoa  (Quincy  F. 

Roberts)  .  471 

*Why   Life  is  Interesting  to  a  Commercial 

Operator  (A.  Henry)   67 

Will  the  Composer  Pay  for  Broadcasting?   271 

Will  the  Entire  Nation  Listen  to  the  Next 

President's  Inaugural  Address?   13 

*With  MacMillan  and  Radio,  North  of  Civili- 
zation (E.  F.  McDonald  Jr.)   500 

*With  the  Broadcasters   135 

*World    at   Your   Finger   Tips,    The  (H. 

Blumenfeld)   426 

PORTRAITS 

(♦Portraits  in  "The  March  of  Radio") 

*Alexanderson   279 

*Alexanderson,  Verner   279 

*  Armstrong,  Edwin  H   5 

Armstrong,  Edwin  H   194 

Axt,  William   460 

Baldwick,  Edna   460 

Bartholomew,  Richard   477 

Bennett,  Edith   135 

Bouck,  Zeh   442 

Bucher,  Elmer  E   195 

*Burghard,  George   5 

Burghard,  George  E   291 

*Byers,  L.  S   5 

Caddell,  Alfred  M   444 

Carnido,  M   428 

Carter,  M.  G   312 

*Cole,  Cornelius   455 

♦Cooper,  C.  B   276 


PAGE 

Cromwell,  Frank   301 

Crosley,  Poweljr   323 

*Delaney,  J.  J   94 

Dellinger,  J.  H   266 

Dill,  Herbert  E   315 

Donnelly,  Thorne   411 

*Doyle,  Arthur  Conan   181 

Dreher,  Carl  H   264 

Finke,  J.  H.  L   493 

♦Fleming,  A.  P.  M   15 

♦Fleming,  J.  A   186 

*Freisinger,  George   275 

♦Fremantle,  Sir  Edmund  Robert   8 

Gallagher   519 

Gillett,  Ransom  H   178 

Godley,  Paul   157 

*Golden,  Claude   366 

Goldsmith,  Alfred  N   246 

Grimes,  David  H   356 

Harbord,  James  G   246 

*Harding,  Warren  G   360 

Haynes,  Artemas  J   406 

Hempel,  Frieda   246 

Henry,  A   356 

Hoar,  Roger  Sherman   264 

Hogg,  Frederic  L   493 

Hoover,  Herbert  C   2 

Horine,  E.  E   266 

Huse,  H.  F   317 

Jenkins,  Elliott   411 

Jones,  Frank  H   370 

*Lapointe,  Ernest   273 

Lecuona,  Ernesto   460 

Lewis,  George   192 

Lynch,  Arthur  H   229 

McCoy,  N.  M   122 

McDonald,  E.  F.  Jr   504 

MacMillan,  Donald  B  281,502,507 

♦Man,  Shu  S   13 

Maude,  Cyril   470 

Mayo,  R.  R   221 

Morecroft,  J.  H   264 

O'Keefe,  Patrick   129 

Ormandy,  Eugen   462 

Orr,  Billie   302 

*Ostman,  Frederick  R   98 

*Pacent,  Louis  G   5 

Parsons,  Fred  25,26 

Pershing,  John  J   428 

*Pickerill,  E.  N   362 

Rapee,  Erno   462 

Roberts,  Quincy  F  472,474 

Roberts,  W.  VahV   356 

Robertson,  Charles  H   385 

Robyn,  William   461 

Rothafel,  S.  L  246,458,463 

Sarnoff,  David   196 

Scheerer,  Louise   461 

Shalkhauser,  Eric  G  418,419,420 

Shean   519 

Squier,  George  Owen   446 

Squire,  Frank  M   196 


INDEX— Continued 


PAGE 

*Squire,  Frank  M   361 

Stralia,  Elsa   461 

*Strohm,  Christian,   11 

Taylor,  Mildred   229 

Taylor,  Peter   229 

Thomson,  Basil   93 

*Thomson,  Joseph   183 

Walska,  Ganna   135 

Wheeler,  Wayne  B   178 

White,  Abbye  M   421 

White,  W.  C   442 

Woodruff,  George   490 

Young,  Owen  D   246 


AUTHORS 

Bartholomew,  Richard   304 

Blumenfeld,  H   426 

Boscow,  A.  R   325 

Boucheron,  Pierre  254,494 

Bouck,  Zeh  23,230,319,391,496 

Bowles,  Edward  Lindley  123,214 

Bradley,  J.  Townsend   146 

Burghard,  George  E   290 

Caddell,  Alfred  M  128,406 

Cardwell,  Allen  D  430,511 

Carter,  M.  G   311 

Clark,  A.  G   28 

Crouse,  George  B   142 

Dellinger,  J.  H   241 

Denning,  J.  W   484 

Dill,  Herbert  E   314 

Dreher,  Carl   190 

Euray,  Allison   22 

Godley,  Paul  F   154 

Grimes,  David  H  

Harrington,  E.  D  

Harris,  William  Jr. .  .  . 

Henry,  A  

Herts,  Jacques  H  

Hoar,  Roger  Sherman 


PAGE 

Horine,  E.  E  74,247 

Huse,  H.  F   316 

Jacquet,  Lloyd   331 

Jasperson,  R.  0   20 

Jenkins,  J.  Elliott   411 

Jessup,  Elon   102 

Jones,  Frank  H   368 

King,  Arthur  N   210 

Kirk,  Grayson  L   35 

Levin,  Claude  Cathcart   159 

Lynch,  Arthur  H   251 

McDonald,  E.  F.  Jr   500 

McLeary,  F.  Burnham   282 

M.,  J.  H  3,91,179,269,359,447 

Munzig,  Arthur  L   476 

N.,  J.  T   219 

Nelem,  Frank   480 

Oliver,  Robert  ;   202 

Plough,  Alvin  Richard   323 

Poison,  Alex.  V   288 

Procter,  Frederic  W   29 

Reith,  L   486 

Roberts,  Quincy  F   471 

Roberts,  Walter  VanB  16,108,340 

Robertson,  C.  H  :   382 

Rodgers,  W.  W  118,397 

Rothafel,  S.  L   458 

Shalkhauser,  Eric  G   417 

Simpson,  J.  L   299 

Sleeper,  M.  B   404 

Smith,  Leland  L   42 

Standiford,  W.  S   161 

Stark,  Kimball  H   38 

346 
421 
375 
133 
112 
62 
236 


  197 

  234 

 114,465 

67,149,222,336 

  52 

.  .  .55,136,205 


Weaver,  Roger  A.. .  . 
White,  Abbye  M. .  .  . 

White,  W.  C  

Whitefield,  Charles  T 

Wilson,  Willard  

Winters,  S.  R  

Witherby,  Lester.  .  . 


Revised  List  of  Broadcasting  Stations 


The  "Brief-Case"  Single-Tube  Loop  Set 


\  .-»\ 


Why  Life  is  Interesting  to  a 
Commercial  Operator 

;rodyne"  Receiving  System 


Dry  Cells  and  WD-ll's 


Transmitting  and  Receiving  with 
the  Same  One-Tube  Set 


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Tubes  for  Every  Requirement 


Vacuum  tubes  are  used  for  two  distinct  individual  purposes  in  a  receiving 
set— as  DETECTORS  and  as  AMPLIFIERS.  The  qualifications  of  a  tube 
for  these  two  uses  are  so  different  that  for  maximum  efficiency  tubes  of 
entirely  different  design  must  be  used. 

This  point  was  one  of  the  chief  considerations  of  the  research  engineers 
who  designed  Cunningham  tubes  in  the  great  laboratories  of  the  General 
Electric  Company.  After  years  of  research  and  experimental  work,  the 
Cunningham  C-300,  a  SUPER-SENSITIVE  DETECTOR,  the  Cunningham 
C-301,a  DISTORTIONLESS  AMPLIFIER,  and  the  Cunningham  C-301  A, 
a  LOW  FILAMENT  CURRENT  AMPLIFIER,  were  developed.  These 
three  tubes,  now  nationally  recognized  as  standards  for  all  types  of  receiving 
sets,  are  responsible  for  the  highly  perfected  results  obtainable  in  radio 
phone  reception. 


The  trade  mark  GE  is 
the  guarantee  of  these 
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specifications. 


TYPE  C-300 

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Patent  Notice 


Cunningham  tubes  are 
covered  by  patents 
dated  11-7-05,  1-15-07,  2-18-08,  and  others  issued 
and  pending.  Licensed  for  amateur,  experimental, 
and  entertainment  use  in  radio  commu- 
nication. Any  other  use  will 
be  an  infringement 


Home  Office: 

248  First  Street 
San  Francisco,  Calif. 


Eastern  Representative: 

154  West  Lake  St.,  Chicago,  Illinois 


-fc  Tested  and  approved  by  Radio  Broadcast  -fa 


RADIO  BROADCAST  ADVERTISER 


That  the  Kennedy  "Universal" 
set  is  a  wonderful  example  of 
mechanical  excellence  is  shown 
by  this  interior  view.  It  can  be 
made  to  detect,  regenerate  or 
oscillate  over  its  entire  range  of 
200  to  25,000  meters. 

All  Kennedy  Regenerative  Re- 
ceivers are  licensed  under  Arm- 
strong U.  S.  Patent  No.  1,113,- 
149. 


inest  Homes 


IT  IS  but  natural  that  Kennedy  Receiving  Sets 
are  found  in  the  finest  homes.  The  same  ap- 
preciation of  artistry  that  is  responsible  for  beauti- 
ful home  surroundings  sees  in  a  Kennedy  a  fitting 
example  of  craftsmanship  that  belongs  with  the 
finest. 

Again — the  clarity  of  reception,  freedom  from 
extraneous  noises,  and  greater  elimination  of  inter- 
ference made  possible  by  a  Kennedy  appeals  to 
the  true  lover  of  music  and  the  finer  things  of  life. 
The  long  range  places  the  music  of  the  continent 
within  your  reach. 

And  last — the  owner  of  a  Kennedy,  knows  that 
others  will  admire  it.  Its  possession  reflects  good 
taste  and  judgment. 

Arrange  with  your  local  dealer 
Jor  demonstration,  or  write  us 
direct  for  descriptive  literature, 

THE  COLIN  B.  KENNEDY  COMPANY 
SAINT  LOUIS  SAN  FRANCISCO 


*  KENNEDY 


*k  Tested  and  approved  by  Radio  Broadcast  -fa 


Radio  Broadcast 


ARTHUR  H.  LYNCH,  Editor 


CONTENTS  FOR  MAY,  1923 

Herbert  C.  Hoover,  Secretary  of  Commerce     -    --    --    --    --    --    --    --    --  Frontispiece 

THE  MARCH  OF  RADIO    -------  -   3 

A  SINGLE-TUBE  LOOP  SET  IN  A  BRIEF-CASE  -    ------     Walter  Van  B.  Roberts  16 

CONFESSIONS  OF  AN  UNMADE  MAN         ------  R.  O.  Jasperson  20 

Drawings  by  Thomas  E.  Monroe 

RADIO  AS  A  RENT  INDUCEMENT       -   -   -  -   -   -   Allison  Euray  22 

THE  "HAM"  SET  OF  aN  OLD  SHIP  OPERATOR   -   -   Zeh  Bouck  23 

THE  TUNING  TROUBLES  OF  MESSRS.  GALLAGHER  AND  SHEAN    -   -   -   -   A.G.Clark  28 

TRANSMITTING  AND  RECEIVING  WITH  THE  SAME  ONE-TUBE  SET  Frederic  W.  Procter  29 

HAVE  YOU  HEARD  THESE  STATIONS  YET?  -----------------  33 

SUPPLYING  BROADCASTING  LIKE  GAS  OR  ELECTRICITY      -    -    -    Grayson  L.  Kirk  35 

THE  "NEUTRODYNE"  RECEIVING  SYSTEM     --------    -  Kimball  H.  Stark  38 

AN  S  O  S  IN  THE  JUNGLE  OF  INDO-CHINA-  -    -    Leland  L.  Smith  42 

ADDING  TWO  STEPS  TO  YOUR  AERIOLA  SENIOR            -   -   -   -     Jacques  H.  Herts  52 

WHAT  CAN  BE  PATENTED?        -    -  Roger  Sherman  Hoar  55 

Drawings  by  Thomas  E.  Monroe 

LISTENING  TO  A  BROADCAST  PROGRAM  AT  HOTEL  BELLEVUE,  SAN  FRANCISCO  60 

A  RADIO  CODE  WITH  ELEVEN  MILLION  VARIATIONS        -----    S.  R.  Winters  62 

AMONG  THE  "HAMS"   64 

ALL  BOY  SCOUTS,  ATTENTION!  -------  -   66 

WHY  LIFE  IS  INTERESTING  TO  A  COMMERCIAL  OPERATOR  A.  Henry  67 

THE  BROADCAST  RECEIVING  CONTEST— RULES  AND  PRIZES  -   -   -   -  73 

SIX-INCH  DRY  CELLS  AND  WD-11  TUBES      -----------    E.  E.  Horine  74 

REVISED  LIST  OF  ALL  U.  S.  AND  CANADIAN  BROADCASTING  STATIONS     -   -   -   -  78 

THE  GRID— QUESTIONS  AND  ANSWERS     -------  -   -  79 

NEW  EQUIPMENT     ------   88 

Copyright,  1923,  by  Doubleday,  Page  &  Co.  All  rights  reserved 
TERMS:  $3.00  a  year;  single  copies  25  cents 
F.  N.  Doubleday,  Pres.  Arthur  W.  Page,  Vice-Pres.  Nelson  Doubleday,  Vice-Pres. 

Russell  Doubleday,  Sec'y.  S.  A.  Everitt,  Treas.  John  J.  Hessian,  Asst.  Treas. 

DOUBLEDAY,  PAGE  &  CO. 

The  World's  Work  Country  Life  The  Garden  Magazine  Short  Stories 

Educational  Review  Health  Builder 

CHICAGO:  People's  Gas  Bldg.  GARDEN  CITY,  N.  Y.  NEW  YORK:  120  W.  32nd  Street 

L  BOSTON:  Tremont  Bldg.  LOS  ANGELES:  Van  Nuys  Bldg.  A 


Uniform  current  cuts  out  the  noise 

EVERY  radio  amateur  knows  how 
disastrous  battery  noises  are  to 
clear  receiving.  You  can  avoid  this  an- 
noying interference  by  getting  the  bat- 
tery that  insures  a  steady  flow  of  fila- 
ment current.  That  battery  is  the  Exide 
Radio  Battery. 

This  specially  designed  radio  battery  does 
its  work  uncomplainingly,  and  never  requires 
much  attention.  The  rasping,  snarling  noises 
often  caused  by  fluctuating  current  in  ordi- 
nary batteries  do  not  exist  in  the  Exide  Bat- 
tery. It  delivers  uniform  filament  current  for 
every  type  of  vacuum  tube.  You  can  count  on 
the  Exide  for  dependable,  long-lasting  service. 

Exide  Batteries  are  used  in  a  majority  of  the 
government  and  commercial  wireless  stations 
and  in  every  industry  where  a  battery's  re- 
sponse to  the  call  of  duty  must  not  fail. 


Any  dealer  in  radio  equipment  will  sell  you 
an  Exide  Radio  Battery,  or  you  can  get  one 
at  the  nearest  Exide  Service  Station. 

THE  ELECTRIC  STORAGE  BATTERY  CO. 
Philadelphia,  Pa. 


Service  Stations  Everywhere 
Branches  in  Seventeen  Cities 


■^r  Tested  and  approved  by  Radio  Broadcast  -fa 


©  Paul  Thompson 

HERBERT  C.  HOOVER,   SECRETARY  OF  COMMERCE 

The  White  Radio  Bill  failed  at  the  last  session  of  Congress,  but  the  radio  world  is  now  looking  to  Secretary 
Hoover  to  make  the  best  of  a  bad  situation  by  regulating  wavelengths  in  so  far  as  his  present  authority  allows 


RADIO 
BROADCAST 

Vol.  3    No.  i  May,  19I3 

The  March  of  Radio 

WHAT  RADIO  BROADCAST  IS  TRYING  TO  DO 


THIS  is  our  first  anniversary  number. 
The  twelve  issues  of  Radio  Broad- 
cast which  have  preceded  this  repre- 
sent twelve  efforts  to  give  you  the 
very  best  magazine  we  could  make. 
It  is  evident  that  no  uncertain  policy,  no  waver- 
ing of  ideals,  and  no  subordination  to  any  selfish 
interest  can  lead  to  the  highest  usefulness  of  this 
or  any  other  publication.  We  believe  that  you 
will  be  interested  in  a  brief  statement,  at  this 
time,  of  just  what  we  stand  for,  what  we  have 
been  trying  to  do,  and  what  interests  Radio 
Broadcast  will  continue  to  serve.  We  believe: 
That  the  most  important  function  of  radio 
is  to  make  life  safe  at  sea ; 

That  closer  and  more  friendly  relations 
between  the  United  States  and  other  nations 
can  and  should  be  fostered  by  means  of  radio 
communication; 

That   in  broadcasting  we  have  a  tre- 
mendous force  which,  properly  directed,  may 
be  a  means  of  incalculable  and  universal 
good;  and  that  every  effort  should  be  made 
to  see  that  this  force  is  fairly  and  intelligently 
used  for  the  benefit  of  the  greatest  number. 
It  is  our  intention  to  continue  a  policy 
which  is  consistent  with  these  beliefs.  First, 
last,  and  always,  we  are  for  "Better  Radio."  We 
make  mistakes,  but  believe  that  those  who  do 
not  make  mistakes,  never  make  anything.  Al- 
though you  may  not  always  agree  with  the  ideas 
we  express,  you  can  always  be  sure  that  we 
believe  what  we  say  and  that  we  make  every 
effort  to  state  the  facts  clearly  and  justly. 


Much  of  our  present  radio  development  is 
directly  traceable  to  that  group  of  electrical 
experts  whom  we  call,  for  lack  of  a  better 
name,  "amateurs/'  There  are  those  who 
would  terminate  the  activities  of  these  experi- 
menters, but  in  our  opinion  such  a  procedure 
would  be  not  only  unjust,  it  would  be  folly,  for 
certain  of  the  amateurs'  activities  are  con- 
ducive to  great  benefits  to  radio. 

Concerning  broadcasting,  this  phase  of  our 
game  is  at  once  the  most  interesting  and 
popular.  Broadcasting  has  done  more  to  ad- 
vance radio  in  the  last  two  or  three  years  than 
all  the  efforts  of  previous  years.  Of  course, 
there  is  much  to  be  desired  in  broadcasting  as 
we  find  it  to-day.  We  need  improved  trans- 
mission, better  programmes,  adequate  wave- 
length regulation,  fewer  high-power  broadcast- 
ing stations, -a  more  satisfactory  distribution  of 
transmitting  stations,  a  reasonable  standard- 
ization of  apparatus.    .    .  . 

We  have  consistently  endeavored  to  promote 
regulation  of  a  helpful  character.  As  you 
know,  you  and  we  have  campaigned  together 
for  legislation  designed  to  bring  about  the 
changes  necessary  for  better  broadcasting. 
Thus,  you  will  see  that  n=_=======n 


Radio  Broadcast  is,  in  a 
sense,  not  our  magazine — it 
is  yours.  We  are  but  players 
on  a  stage,  interpreting  to  the 
best  of  our  ability  for  you, 
our  audience,  without  whom 
there  would  be  no  play. 


4 


Radio  Broadcast 


As  the  Radio  Corporation  Sees  the 
Patent  Situation 

THE  following  letter  from  General  Har- 
bord,  President  of  the  Radio  Corpora- 
tion of  America,  sets  forth  the  Corpora- 
tion's views  on  the  radio  patent  situation.  In 
an  editorial  in  our  March  issue  we  called 
attention  to  the  possible  harmful  results  of 
what  seemed  like  a  tendency  on  the  part  of  the 
Corporation  toward  a  monopoly  in  the  produc- 
tion and  sale  of  radio  apparatus.  Last  month, 
we  published  an  article  entitled 
"Cooperative  Competition",  which 
showed  how  automobile  manufac- 
turers found  a  way  out  of  a  situation 
which  seems  to  us  similar  in  some 
respects  to  that  now  facing  the  radio 
industry. 

We  are  glad  to  publish  General 
Harbord's  letter,  and  we  should  be 
glad  to  publish  letters  from  the  companies  on 
the  other  side  of  the  controversy,  for  this  is 
perhaps  the  most  important  question  in  the 
radio  field  and  one  on  which  all  radio  enthu- 
siasts should  have  information — and  tolerance. 

Radio  Corporation  of  America, 

233  Broadway,  New  York. 
Office  of  the  President 

Mr.  Arthur  Lynch, 

Editor,  Radio  Broadcast. 
My  Dear  Mr.  Lynch: 

1  regret  that  absence  from  the  City  has  prevented 
me  from  complying  with  your  request  transmitted  to 
me  by  Mr.  Stuart  Crocker  for  a  statement  regarding 
the  plans  of  the  Radio  Corporation  with  reference 
to  the  radio  patents  held  by  it.  I  think  you  will 
appreciate  that  it  is  impracticable  in  a  new  art  such 
as  radio  to  make  a  statement  which  shall  at  the  same 
time  be  prophetic  and  accurate.  Suc.h  a  statement 
can  only  be  based  on  present  actual  knowledge.  It 
might  at  any  time  call  for  a  restatement  because  of 
change  of  conditions.  For  the  present,  the  best 
that  any  company  in  the  radio  industry  can  do  is  to 
make  month  to  month  decisions. 

If  I  may  be  permitted  a  word  as  to  the  purposes  of 
the  Radio  Corporation,  I  would  say  that  it  was 
organized  under  the  laws  of  the  country  for  operating 
a  lawful  enterprise,  for  the  same  object  which 
prompts  the  launching  of  any  other  business  institu- 
tion— service  to  the  public  with  the  hope  of  a  fair  re- 
turn, to>  the  stockholders.  In  addition  to  this  legiti- 
mate ambition  for  material  success,  the  corporation 
has  striven  to  be  of  service  in  a  technical  and  patriot- 
ic way.  It  has  aided  in  the  development  of  radio 
art,  and  has  furnished  the  first  American  owned  and 
controlled  means  of  direct  commercial  telegraph 


communication  with  the  principal  foreign  countries, 
making  the  United  States  the  great  centre  and 
leading  factor  in  world  radio  communication.  To 
achieve  these  ends  it  has  been  obliged  to  coordinate 
the  inventive  genius  of  many  individuals.  It  has 
made  great  outlay  for  research  and  development 
work  in  perfecting  its  own  inventions,  and  to  advance 
the  radio  art  it  has  also  been  considered  wise  to  ac- 
quire the  inventions  of  others.  In  no  other  way 
could  the  various  improvements  and  best  features 
of  the  numerous  inventions — no  one  of  them  ade- 
quate in  itself — which  are  regarded  as  requisite  to 
satisfactory  radio  service,  have  been  assembled  and 
made  available  for  the  public  in  any  one 
line  of  apparatus.  Had  the  several  in- 
ventors joined  forces,  the  situation  would 
have  been  the  same  under  some  other 
organization  bearing  a  different  title. 

Thus  far,  the  public  and  a  few  manu- 
facturers and  dealers — some  legitimate, 
but  many  of  them  infringers — have  profited 
from  the  development  and  production 
of  radio  apparatus.  The  stockholders 
of  this  corporation  whose  money  and  faith  in  the 
patent  laws  have  contributed  to  the  technical 
achievements  largely  responsible  for  progress  made 
have  not  yet  drawn  a  dollar  in  profits. 

There  have  been  some  criticism  against  the  Radio 
Corporation  for  bringing  suit  against  various  radio 
manufacturers  for  the  infringement  of  patents.  The 
cry  of  monopoly  and  the  charge  of  oppression  of  small 
manufacturers  are  easily  raised,  and  usually  by 
those  to  whom  the  propriety  of  great  exactness  of 
speech  does  not  appeal. 

The  Radio  Corporation  had  the  absolute  right  to 
enforce  every  patent  which  it  owned  against  every 
user.  It  did  not,  however,  adopt  this  policy,  but 
instead,  in  keeping  with  the  high  ideals  which  have 
characterized  it  since  its  inception,  decided  that  if  an 
amateur  wanted  to  build  his  own  set  for  his  own 
amateur  use  he  could  do  so,  and  that  it  would  not, 
until  further  notice,  treat  such  procedure  as  an  in- 
fringement of  its  patent  rights.  But  there  is  ab- 
solutely no  reason  why  the  Radio  Corporation,  which 
ought  to  earn  dividends  on  the  shares  which  it  issued 
to  clear  this  property  represented  by  important 
patents,  and  which  shares  are  now  owned  by  over 
33,000  stockholders,  should  allow  this  property  and 
patents  to  be  recklessly  trespassed  upon  by  hundreds 
of  rival  manufacturing  companies,  most  of  which 
make  no  contribution  whatever  to  the  art,  have  made 
no  investment  in  property  patent  rights,  and  merely 
attempt  to  reap  where  others  have  sown.  The  Radio 
Corporation  is  therefore  proceeding  to  enforce  some 
of  its  rights  by  the  normal  orderly  process  of  suit 
in  the  Federal  Courts.  It  is  not  attempting  to  create 
a  monopoly;  it  is  attempting  to  enforce  the  lawful 
rights  limited  in  scope  and  in  time  which  it  has  been 
necessary  for  it  to  acquire  in  order  that  the  radio 
art  might  go  forward.  It  is  as  important  to  the  en- 
tire radio  industry  to  have  these  patents  judicially 


The  March  of  Radio 


5 


Armstrong's  super-heterodyne 

In  a  glorified  form,  it  was  one  of  the  features  of  the  radio  exposition  held  in  New  York.  Western  Electric  loud  speakers, 
each  operated  from  its  own  power  amplifier,  were  placed  in  various  points  in  the  Grand  Central  Palace.  The  plate 
voltage  was  supplied  by  a  great  number  of  standard  6-inch  dry  cells,  and  about  thirty-six  vacuum  tubes  were  used.  Radio 
engineers  predicted  failure  for  this  outfit,  which  was  installed  and  operated  by  the  Radio  Club  of  America  with  complete 
success.  Left  to  right,  in  the  picture,  are:  L.  S.  Byers  of  the  Exposition  Company;  Louis  G.  Pacent,  chairman  of  the 
Committee  on  Papers;  George  Burghard,  President;  and  Edwin  H.  Armstrong,  Past  President  of  the  Radio  Club 


tested  as  it  is  to  the  Radio  Corporation.  Not  until 
its  validity  has  been  judicially  determined  is  it  pos- 
sible to  evaluate  the  proper  royalty  basis  for  a 
patent.  Until  this  is  done,  there  will  be  continual 
confusion,  and  the  radio  patent  situation  in  the 
United  States  will  remain  unprofitable  to  inventors 
and  unsound  as  far  as  manufacturers  are  concerned. 
We,  therefore,  have  instituted  suitable  action  to 
reach  sound  conclusions.  We  go  so  far  as  to  believe 
that  all  holders  of  radio  patents  should  do  the  same 
thing,  if  this  present  complex  and  disturbing  situa- 
tion is  to  be  clarified. 

An  infringer  of  patents  has  the  advantage  that  he 
has  no  patent  investment,  no  research  to  finance,  no 
responsibility  to  the  art.  He  can  make  a  thing  and 
sell  it;  if  he  makes  a  dollar  profit  it  belongs  to  him 
until  the  Courts  take  it  away  from  him,  which  can 
only  happen  after  a  long  litigation.  The  great  con- 
cern which  has  made  all  this  development  possible, 
which  has  spent  millions  in  clearing  the  road  for 
American  radio  has  to  earn  something  on  what  it 
spent  in  acquiring  that  pathway.  Enforcement  of 
its  patent  rights  with  the  Federal  Courts  will  help 
it  to  earn  that  something.  If  its  rights  are  not  as 
broad  as  it  believes  them  to  be  the  Courts  will  say  so. 


In  its  efforts  to  test  its  rights  and  find  out  just  what 
they  really  are  and  to  enforce  them  the  Radio  Cor- 
poration should  have  the  sympathy  of  everyone  who 
really  wishes  the  good  of  the  radio  art;  for  if  such 
rights  acquired  under  such  circumstances  and  at 
such  cost  are  not  sustained  and  enforced,  who  again 
will  feel  justified  in  taking  the  risks  and  making  the 
expenditures  that  were  taken  and  made  when  the 
Radio  Corporation  was  formed? 

We  must  have  it  clear  in  our  minds  that  a  patent 
under  the  constitutional  laws  of  the  United  States 
grants  to  the  inventor  or  to  the  person  to  whom  he 
has  assigned  the  patent,  the  exclusive  right  of  its  use. 
This  means  that  with  perfect  legality  and  due  regard 
for  the  ethics  of  the  situation,  the  Radio  Corpora- 
tion has  such  exclusive  right  to  its  property  in 
patents.  Any  one  not  in  agreement  with  this  dis- 
agrees with  the  Constitution  of  the  United  States 
and  the  laws  passed  in  conformity  with  it  having  for 
a  purpose  the  establishing  of  patent  privileges  to 
inventors  and  owners  of  patents. 

There  has  been  a  suggestion  for  a  cooperative 
pooling  of  radio  patents  in  order  that  all  companies 
can  manufacture  radio  apparatus  without  fear  of 
patent  difficulties.    According  to  the  best  of  my  in- 


Radio  Broadcast 


A  PRICELESS  BOON 

To  an  ordinarily  active  person  who  is  forced  by  accident  or  illness  to  pass  many  long  hours  of  inactivity,  a  broadcast 
receiving  set  is  a  blessing.  William  Snider,  repairman  for  the  Bell  Telephone  Company,  broke  both  arms  and  legs  in  a 
fall  from  a  pole  recently,  in  Canton.  Ohio.  Friends  among  his  fellow  workers  conceiv  ed  the  idea  that  a  radio  set  might 
help  to  pass  the  tedious  hours.  Accordingly,  a  receiver  was  installed,  and  the  patient  was  able  to  keep  in  touch 
with  the  world  beyond  his  hospital  window,  hearing  the  concerts  every  afternoon  and  evening 


formation,  no  cooperative  pooling  of  patents  in  any 
industry  has  ever  been  effective  until  this  initial 
stage  has  been  passed.  The  pooling  arrangement 
does  not  take  place  during  the  nebulous  period  under 
which  the  developed  art  passes.  Future  inventions 
and  developments  will  probably  very  greatly  change 
the  radio  art  as  we  know  it  to-day. 

The  future  policy  of  the  Radio  Corporation  re- 
garding patents  cannot  be  more  definitely  stated  at 
this  time.  1  am  glad  to  give  assurance,  however, 
that  we  intend  to  be  as  helpful  to  the  rapid  advance- 
ment of  the  radio  art  as  it  is  within  our  power  to  be. 
The  United  States  should  be  proud  of  its  position 
in  the  development  of  radio  throughout  the  world. 
It  is  with  the  avowed  purpose  of  maintaining  this 
position  that  the  corporation  will  always  approach 
the  solution  of  radio  problems. 

By  coincidence,  the  laws  under  which  we  claim  our 
rights  are  based  on  the  same  provision  of  the  United 
States  Constitution  which  protects  your  employers 
in  the  publishing  business,  namely,  Clause  8  of 
Article  1.  If  you  should  write  a  scientific  work  as  a 
result  of  your  years  of  labor  and  study,  and  bring  it 
out  at  great  expense,  would  you  think  it  a  crime  or 
injustice  to  others  who  were  endeavoring  to  steal 
your  work  that  they  should  be  enjoined  from  doing 


so  for  a  limited  period  granted  you  in  which  to  realize 
some  legitimate  profit  from  your  work?  That  is  a 
similar  question  to  the  one  which  has  to  be  decided 
by  the  officers  of  this  corporation,  representing  over 
33,000  stockholders  whose  motives  are  impugned 
by  statements  in  an  editorial  appearing  in  the  March 
issue  of  Radio  Broadcast. 

I  am  sure  that  with  this  frank  statement  I  can  con- 
fide in  your  fairness  to  the  Radio  Corporation  in  the 
future. 

Sincerelv  vours, 


The  Effect  of  Broadcasting  on  Sermons  and 
Speeches 

THE  pioneer  radio  preacher  of  Pittsburgh, 
the  Rev.  Dr.  E.  J.  Van  Etten  of  Calvary 
Protestant  Episcopal  Church,  gave  his 
opinion  recently  on  the  effect  which  radio 
might  be  expected  to  have  on  church  services. 
He  has  probably  thought  along  these  lines 
as  much  or  more  than  anv  other  churchman, 


The  March  of  Radio 


7 


and  has  had  enough  experience  in  the  matter  to 
have  reached  some  interesting  conclusions. 

We  cannot  doubt  that  the  radio  church  ser- 
vice is  here  to  stay,  just  as  is  the  concert  and 
opera.  What  will  be  the  effect  on  the  churches 
themselves  of  thus  spreading  their  service  over 
a  large  territory  with  possibly  thousands  of 
listeners?  Such  an  innovation  cannot  be 
introduced  without  having  some  reaction  on 
the  man  conducting  the  service.  Some  of  the 
churches  have  a  perfectly  fixed  service  routine 
so  that  no  changes  in  this  respect  can  be  ex- 
pected; the  flexible  feature  of  any  church 
service  is  the  sermon,  and  the  preacher  of  the 
sermon.  The  ritualistic  churchman  will  assert 
that  the  personality  and  ability  of  the  preacher 
have  little  to  do  with  the  value  of  a  church 
service,  but  to  the  average  church-goer  the 
preacher  is  of  paramount  importance.  Man}' 
people  go  to  church  "to  hear  Dr.  So-and-So." 

Doctor  Van  Etten,  in  a  recent  sermon  on  this 
question,  said  that  in  his  opinion  "broadcasting 
of  church  services  will  prove  something  of  a 
disintegrating  force  on  the  church  organizations 


themselves.  Only  the  fittest  preachers  will 
survive,  and  struggling  churches  will,  more  or 
less,  go  to  the  wall."  This  seems  like  a  very 
sensible  conclusion — a  preacher  of  mediocre 
caliber  can  hold  his  congregation  only  so  long  as 
other  and  more  inspiring  men  are  not  available. 
When  the  congregation  can  stay  at  home  and 
hear  the  wonderful  musical  service  from  a 
metropolitan  church,  and  listen  to  the  words  of 
a  superior  mind,  the  small  country  church  with 
its  itinerant  pastor  is  quite  likely  to  suffer. 

In  his  sermon,  Doctor  Van  Etten  further 
stated  that  "radio  religion  is  not  a  substitute 
for  public  worship.  It  must  become  active 
and  not  passive."  This  brings  up  the  question 
of  the  effect  of  radio  broadcasting  upon  church 
attendance;  will  many  people  be  content  to  take 
their  religion  from  the  loud  speaker?  If  we 
can  accept  the  explanation  of  the  large  crowds 
at  the  Manhattan  Opera  House  recently,  the 
attendance  at  church  will  increase  rather  than 
decrease  as  a  result  of  broadcasting,  that  is  if 
the  service  is  carried  out  in  an  appealing  and 
inspiring  manner  and  if  the  preacher  shows 


GATHERING  WEATHER  REPORTS  AT  A  POWERFUL  GERMAN  STATION 


The  reports  received  from  Paris,  Warsaw,  Christiania,  London,  and  other  cities  are  used  to 
make  up  the  daily  forecasts  broadcasted  from  this  radio  telegraph  station  located  in  Berlin 


8 


Radio  Broadcast 


ability  and  sincerity  in  his  words.  In  fact, 
this  condition  has  already  been  observed  fol- 
lowing the  weekly  broadcasting  of  the  Men's 
Conference  at  the  Bedford  Y.  M.  C.  A.  in 
Brooklyn,  N.  Y. 

This  idea  of  forcing  the  preachers  to  improve 
the  quality  of  their  sermons  leads  us  to  a  sug- 
gestion for  many  of  our  celebrated  after-dinner 
speakers.  They  don't  realize  it,  of  course,  but 
the  radio  audience  is  composed  of  nearly  the 
same  individuals  every  evening,  even  though 
those  listeners  directly  in  front  of  them  may  be 
different.  The  professional  after-dinner  artist 
has  been  able  to  earn  his  meal  ticket  rather 
easily  in  the  past;  one  set  of  stories  might  go 
for  the  whole  season  if  he  was  careful  concern- 
ing the  invitations  he  accepted.  But  not  so 
now.  We  recently  heard  one  of  our  national 
figures  tell  the  same  stories  on  three  different 
occasions,  all  within  a  week.  It's  well  that  he 
didn't  know  how  many  of  us  had  already  heard 


about  the  marriage  of  his  chauffeur,  as  it  would 
have  taken  all  the  fun  out  of  his  narration.  It's 
interesting  to  know  also  that  some  speakers 
have  had  to  change  somewhat  the  quality  of 
their  stories,  for  they  never  know  who  is  going 
to  hear  them. 

The  Sunrise  and  Sunset  Barrier  to  Signals 

EVERY  careful  observer  has  noticed 
that  the  distant  stations  seem  to  be 
erratic  in  the  way  they  "come  in." 
Some  evenings  the  signal  received  may  be 
consistently  strong,  and  on  others  it  may 
fluctuate  greatly  in  strength  even  during  the 
course  of  an  hour  or  less. 

According  to  one  of  our  correspondents, 
certain  stations  show  this  fading  phenomenon 
with  a  remarkable  degree  of  regularity;  his 
observations,  which  he  has  sent  us,  show  a 
striking  resemblance  to  those  of  Marconi  when 


  — ;   -  ©  Underwood  &  Underwood 

NOTHING  LIKE  THIS  WHEN  HE  TROD  THE  QUARTERDECK 
England's  oldest  seadog,  the  Hon.  Sir  Edmund  Robert  Fremantle,  Rear  Admiral  of  the  United  Kingdom  since  1901, 
recently  listened  to  a  concert  broadcasted  from  the  Eiffel  Tower,  in  the  cabin  of  his  old  ship,  H.  M.  S.  Impregnable. 
Admiral  Fremantle  entered  the  Navy  in  1849,  in  the  real  days  of  "ships  of  oak  and  men  of  steel,"  when  muzzle-loading 

cannon  lined  the  decks  of  tall-masted  frigates 


The  March  of  Radio 


9 


that  pioneer  was  first  trying  to  bridge  the 
Atlantic.  As  any  student  of  radio  knows, 
Marconi  found  it  almost  impossible  to  send  his 
signals  across  the  sunset  or  sunrise  line.  When 
the  sun  was  up  in  Ireland  and  not  yet  up  in 
Newfoundland,  the  sunrise  line  was  between 
the  two  stations  and  this  line  seemed  to  act 
as  a  kind  of  check  to  the  electric  waves.  The 
signals  acted  the  same  way  when  the  sun  had 
set  in  Ireland  and  had  not  yet  set  in  Newfound- 
land. This  effect  is  not  noticed  to  any  great 
extent  by  the  long-wave,  high-powered  stations 
used  for  transatlantic  service  to-day,  but  with 
Marconi's  shorter-wave,  lower-power  stations 
it  was  a  very  important  factor.  The  fading  of 
signals  noted  above  is  probably  similar  in 
nature  to  the  troubles  encountered  by  Marconi. 

When  two  stations  are  broadcasting  with 
carrier  waves  within  a  meter  or  less  of  one 
another  they  produce  a  constant  singing  note 
in  the  receiving  set,  even  when  this  set  is  not 
oscillating.  (With  the  rapid  increase  in  num- 
ber of  broadcasting  stations  this  beat  note 
interference  becomes  very  much  of  a  nuisance 
when  reception  from  distant  stations  is  being 
attempted.)  Our  correspondent,  who  lives 
about  one  hundred  miles  from  New  York, 
on  listening  to  the  beat  note  between  a  New 
York  station,  and  a  Chicago  station,  reports 
the  note  just  audible  when  the  sun  is  up  in 
New  York  City;  as  soon  as  the  sun  sets  at  his 
station  he  observes  that  the  beat  note  at  once 
increases  several  times  in  intensity  and  that 
about  an  hour  later,  when  the  sun  is  setting  in 
Chicago,  a  remarkable  increase  in  signal 
strength  occurs,  the  increase  not  being  gradual 
but  occurring  very  ,  suddenly.  This  action  is 
so  regular,  he  reports,  that  he  can  tell  v/ithin 
a  minute  or  two  when  the  sun  sets  in  Chicago! 

Several  very  capable  experimenters  have 
been  engaged  during  the  past  year  in  making  a 
continuous  record  of  signal  strengths  from 
those  stations  which  seem  to  fade  most  regu- 
larly and  we  may  expect  their  work  soon  to 
give  us  some  reliable  data  on  the  fading 
phenomena. 

Transmitting  Standard  Wavelengths  for 
Calibrating  Sets 

THE  scheme  of  transmitting  standard 
wavelengths  from  the  Bureau  of  Stand- 
ards, which  we  suggested  as  possible 
and  advisable  in  our  last  issue,  has  already 
been  inaugurated.    The  first  standard  signals 


were  transmitted  on  March  6th  from  11.00 
p.  m.  to  i.i 5  a.  m.,  this  time  having  been 
chosen  because  it  was  freer  from  interference 
than  the  early  part  of  the  evening.  Every 
twenty  minutes  during  this  period  the  wave- 
length was  changed  so  that,  during  the  two 
hours,  seven  standard  wavelengths,  from  550 
meters  to  1500  meters,  were  transmitted. 
Preliminary  tests  carried  out  on  January  31st 
showed  the  feasibility  of  the  scheme  and  also 
convinced  the  Bureau  that  it  was  worth  while. 

Much  of  the  work  of  the  radio  department 
of  the  Bureau  has  to  do  with  calibration  of 
condensers,  coils,  and  wavemeters.  These 
instruments  have  to  be  shipped  by  the  owner 
to  the  Bureau,  tested,  and  then  shipped  back; 
not  only  is  this  an  unnecessarily  expensive 
procedure  but  it  has  been  in  the  past  extremely 
unsatisfactory,  as  the  handling  of  the  instru- 
ment by  the  express  employees,  subsequent  to 
its  calibration,  and  before  the  owner  received 
it,  many  times  subjected  it  to  jarring  sufficient 
to  make  the  certification  of  the  Bureau  at  least 
doubtful — and  that  is  really  as  good  as  no 
certification  at  all. 

Not  only  must  laboratories  have  accurate 
calibration  of  their  apparatus,  but  every  intelli- 
gent radio  listener  would  like  to  have  his 
receiving  set  calibrated  for  wavelength,  so 
that,  instead  of  "feeling  around"  for  the 
signal  of  a  certain  station  he  could  at  once 
adjust  his  set  to  the  wavelength  on  which  the 
desired  station  was  to  transmit  and  if  no  signal 
was  heard  he  would  conclude  that  the  station 
was  not  on  the  air.  Hence,  the  average 
listener  welcomed  the  news  that  standard 
wavelengths  were  being  transmitted  and  hoped 
that  they  would  soon  include  the  broadcast 
range. 

The  calibration  signals  sent  out  by  the 
Bureau  are  continuous-wave  signals  and  can 
be  received  only  by  the  heterodyne  principle; 
the  local  receiver  must  be  made  to  oscillate  by  a 
tickler  coil  or  other  means,  and  the  Bureau's 
call  will  give  the  characteristic  whistling  note 
signal.  By  adjusting  the  receiving  set  to  make 
the  beat  note  have  zero  frequency,  a  point  on 
the  variable  condenser  is  obtained,  which  tunes 
the  set  to  exactly  the  frequency  the  Bureau  is 
broadcasting;  this  setting  is  extremely  accurate 
and  the  set  may  be  calibrated  to  a  fraction  of 
a  meter  if  its  construction  has  been  sufficiently 
well  carried  out.  The  tickler  coil  coupling 
should  be  as  loose  as  is  possible  and  still  main- 
tain oscillations,  otherwise  its  adjustment  will 


IO 


Radio  Broadcast 


r 

©  Underwood  &  Underwood 

LISTENING  TO  THE  GOVERNMENT  BROADCAST  IN  AN  ENGLISH  HOME 

The  English  experimenter  has  been  going  through  a  stage  of  development  in  radio  construction  familiar  to  all  "old- 
rimers"  in  this  country:  working  units  of  all  sorts  and  sizes  are  placed  on  a  board  and  wired  up  regardless  of  compactness, 
appearance,  and  simplicity  of  operation.  The  Englishman  has  done  some  excellent  work  in  constructing  his  own  equip- 
ment, however,  and  some  of  the  commercial  companies  produce  apparatus  that  would  be  hard  to  beat  anywhere 


make  the  calibration  of  the  receiving  set  less 
accurate. 

As  this  goes  to  press,  we  learn  that  about 
April  i  st  another  set  of  signals,  from  300  to 
600  meters,  is  to  be  broadcasted,  and  about 
May  ist  another  set  of  from  125  to  300  meters 
will  be  sent  out.  These  tests  will  be  repeated 
periodically  so  that  checks  on  the  accuracy 
of   apparatus   many   frequently   be  made. 

Considering  the  small  staff  engaged  in  radio 
work  at  the  Bureau  of  Standards,  and  the 
importance  of  work  like  that  mentioned  above, 
we  have  sometimes  questioned  the  judgment 
shown  as  to  what  problems  should  be  studied 
by  the  Bureau.  The  circulars  recently  issued 
on  the  testing  of  receiving  sets,  and  that  on  the 
specifications  for  dry  cells,  are,  in  our  opinion, 
illustrations  of  work  which  the  Bureau  should 
not  attempt;  there  is  so  much  work  of  more 


importance  to  be  done.  We  believe  this 
broadcasting  of  standard  waves  is  one  of  the 
best  services  the  Bureau  has  yet  done  for  the 
radio  public,  and  we  expect  that  the  accuracy 
of  the  signals  will  warrant  the  faith  we  shall 
put  in  them. 

Boosting  the  Box-Office  Receipts  at  the 
Opera 

THE  following  article,  which  appeared 
in  the  New  York  Times  for  February 
20th,  provides  an  interesting  field  for 
speculation  as  to  the  coming  relations  between 
opera  in  the  opera-house  and  opera  via  radio — 
at  home  : 

RADIO   "FANS,"    DRAWN   TO   GERMAN    OPERA,    RECALL  THE 
CROWDS  OF  HAMMERSTEIN  DAYS 

Without  warning  save  for  such  explanations  as  followed 
the  Manhattan's  first  "broadcasting"  of  an  opera  here  two 


The  March  of  Radio 


nights  previously,  the  former  Hammerstein  Theatre  in 
Thirty-fourth  Street  was  besieged  by  opera-goers  all  day 
yesterday  and  its  lobbies  were  the  scene  of  a  wild  but 
friendly  "riot"  last  night  when  the  Wagnerian  Opera 
Festival  began  its  second  week  with  a  packed  house  for 
"Die  Meistersinger."  At  first  the  management  was  at  a 
loss  to  account  for  the  crowd,  some  hundreds  of  whom  had 
to  be  turned  away  for  lack  of  either  seats  or  standing  room. 

Then  it  was  suggested  that  the  wide  public  interest  had 
resulted  from  Saturday's  experiment,  when  a  performance 
of  "The  Flying  Dutchman"  had  been  sent  by  radio  out  to 
a  city  and  suburban  population  of  millions  from  the 
Westinghouse  plant  at  Newark,  N.  J.,  the  music  having 
been  conveyed  to  that  place  on  a  wire  installed  in  the 
Manhattan  stage  by  the  Postal  Telegraph  Company. 
Influential  members  of  the  Metropolitan  directorate  had 
likewise  heard  it  and  there  were  those  who  said  the  result 
might  change  the  policy  of  the  older  Broadway  house, 
which  hitherto  had  barred  the  broadcasting  of  opera  by 
radio. 

It  would  seem  that  even  the  Metropolitan 
Opera  Company,  with  its  ordinarily  well-filled 
house,  cannot  afford  to  overlook  the  possibili- 
ties in  the  situation  and  we  hope  that  the 
directors  will  soon  reverse  their  decision  not  to 
permit  the  broadcasting  of  its  performances. 


For  those  of  us  whom  distance  and  expense 
prevent  from  going  to  see  the  famous  operas, 
now  and  then,  such  an  announcement  would 
be  most  welcome. 

What  is  the  Range  of  a  Broadcasting 
Station? 

WE  HEAR  so  much  nowadays  about 
the  remarkable  distances  covered  by 
broadcasting  stations  that  one  may 
reasonably  suppose  that  the  audience  of  one  of 
the  better  class  stations  often  numbers  tens  of 
thousands.  Practically  any  quiet  evening 
we  can  hear  stations  a  thousand  miles  away 
and  we  are  informed  by  the  National  Radio 
Chamber  of  Commerce  that  there  are  be- 
tween one  and  two  million  receiving  sets  in 
the  country.  Figuring  only  two  or  three 
listeners  to  a  set  gives  a  total  radio  audience 
of  about  five  million.  If,  then,  reception  over 
a  thousand  miles  is  reasonable,  an  audience  of 


LISTENING  TO  AN  OPERA  HE  HEARD  IN  1859 
Christian  Strohm  traveled  from  Oldes  Leben  to  Weimar,  Germany,  sixty-four  years  ago  to  hear  the  first  presentation  of  an 
opera  composed  by  Wagner.    This  year,  he  heard  on  a  crystal  set  the  same  music,  broadcasted  from' WI  P.Philadelphia 


I  2 


Radio  Broadcast 


a  million  is  not  at  all  impossible,  however  im- 
probable it  may  be. 

But  how  many  people  actually  do  hear  sta- 
tions one  thousand  miles  away  consistently? 
One  of  our  friends,  living  in  New  York  City, 
who  has  recently  bought  a  modern  receiver, 
confided  in  us  that  although  he  had  a  set  with 
detector  and  two  steps  of  audio-frequency 
amplification,  he  had  never  heard  stations 
farther  away  than  Newark,  twenty  miles  dis- 
tant. He  probably  isn't  the  only  one  who  has 
trouble  hearing  stations  a  thousand  miles  away. 
The  fellows  who  do  hear  distant  stations 
do  a  lot  of  talking  about  it  but  those 
who  have  received  only  within  a  fifty- 
mile  radius  keep  quiet  when  dis- 
tance records  are  being  discussed. 

As  a  matter  of  fact,  to  many 
listeners-in,  there  is  no  particular 
fascination  in  spending  half  the  night 
bringing  in  the  call  letters  of  some 
distant  station, whose  programme  may 
be  mediocre,  when  at  the  same  time, 
a  good  local  station  is  providing  excellent  en- 
tertainment. Nevertheless,  it  would  be  inter- 
esting to  most  of  us — whether  or  not  we  collect 
call  letters  the  way  some  zealots  collect  auto- 
graphs or  postage-stamps — if  one  of  the  popular 
stations,  which  has  received  the  thousands  of 
letters  which  we  hear  about  from  the  announc- 
ers, would  plot  on  a  map,  for  publication,  the  lo- 
cation of  each  of  these  listeners  who  write  in, 
and  so  let  us  know  the  average  distance  of  the 
radio  audience.  We  predict  it  would  be  well 
within  the  thousand-mile  limit,  even  taking 
into  account  the  fact  that  the  long-distance 
listeners  would  be  the  more  likely  to  write.  It 
would  be  illuminating  to  have  on  record  not  the 
number  of  the  possible  radio  audience,  but  the 
actual  number  of  theaudience  listening,  on  a  par- 
ticular evening,  to  any  particular  programme. 

Atchison,  Kansas,  Takes  Control  of  Radio 

KANSAS  is  always  "doing  things,"  so  we 
are  not  surprised  to  hear  of  a  municipal 
regulation  concerning  radio,  enacted  by 
the  commissioners  of  the  city  of  Atchison.  The 
good  people  of  Atchison  evidently  need  some 
special  supervision,  as  we  are  informed  that 
"  three  hundred  aerials  were  ordered  down  by 
the  chief  engineer  of  the  local  lighting  com- 
pany." It  seems  that  the  lighting  company's 
poles  were  being  used  to  hold  up  the  aerials,  in 
spite  of  the  fact  that  these  same  poles  carried 


a  powerful  current  at  2300  volts,  and  1750 
volts  is  as  high  as  is  used  in  Sing  Sing  to  kill  the 
condemned. 

The  ordinance  passed  by  the  commissioners 
has  to  do  with  the  disturbing  influence  of  small 
boys  with  spark  transmitters.  So  it  was 
"  hereby  made  unlawful  for  anybody  unneces- 
sarily and  electrically  to  disturb  the  atmosphere 
within  the  city  limits  of  the  city  of  Atchison 
by  any  means  whatsoever  not  necessarily  in- 
cident to  the  operation  of  some  device,  mechan- 
ism, or  apparatus  used  and  useful  in  any  busi- 
ness, trade,  or  occupation."  Fines  and  im- 
prisonment are  offered  to  disturbers 
of  the  atmosphere. 

The  city  fathers  have  our  approba- 
tion and  well  wishes  in  their  attempt 
to  clear  the  air  of  spark  sets,  but  we 
judge  they  might  have  some  trouble 
in  sending  the  offender  to  jail  if  he 
didn't  go  willingly;  a  shrewd  attor- 
ney might  show  the  city  was  trying  to 
usurp  the  powers  of  the  Federal  Gov- 
ernment in  the  matter;  if  a  certain  small  boy 
happened  to  have  a  federal  license  to  operate  his 
station  we  judge  he  needn't  goto  prison,  no  mat- 
ter how  drastic  might  be  the  municipal  sentence 
imposed.  We  have  heard  of  the  federal  authori- 
ties assuming  control  where  the  state  or  muni- 
cipal machinery  had  broken  down  but  it  seems 
incongruous  to  have  a  small  town  stepping  in  to 
take  care  of  the  federal  authorities'  business. 

Along  this  same  line  we  have  received  some 
clippings  from  the  Daily  Record  of  Kitchener, 
Ontario,  which  indicate  that  our  Canadian 
cousins  also  can  act  in  radio  matters  with  im- 
petuosity and  rashness.  While  we  cannot  con- 
done illegal  acts,  we  do  sympathize  with  the 
Canadians  in  the  situation  which  preceded  their 
attack.  It  seems  that  several  amateurs  with 
spark  sets  had  been  disturbing  the  ether  around 
Kitchener  to  such  an  extent  that  reception  of 
distant  concerts  was  apparently  impossible  for 
some  of  the  listeners.  After  a  period  of  contro- 
versy the  antennas  and  poles  of  the  offending 
stations  were  surreptiously  taken  away  in  the 
night.  Of  course,  if  found  the  perpetrators  may 
be  prosecuted  for  property  damage,  as  the  law 
prescribes,  but  they  are  apparently  not  adver- 
tising their  share  in  the  exploit.  As  for  the  un- 
fortunate station  owners,  they  are  by  no  means 
reconciled  to  their  bereavement:  to  them  the 
proverbial  silence  of  the  Sahara  is  as  the  noise 
of  many  waters  compared  to  the  reign  of  quiet 
around  their  spark  transmitters. 


The  March  of  Radio 


i  i 


Will  the  Entire  Nation  Listen  to  the  Next 
President's  Inaugural  Address? 

ONE  of  the  latest  developments  in 
broadcasting  was  demonstrated  before 
a  large  audience  in  many  sections  of 
the  United  States  on  the  evening  of  February 
14th.  The  event  was  one  of  the  features  of  the 
annual  convention  of  the  American  Institute  of 
Electrical  Engineers,  held  in  New  York  City. 

An  audience  of  several  hundred  people  in 
the  Engineering  Societies  Building,  in  New 
York,  and  another  similar  audience  in  Kimball 
Hall,  Chicago,  were  able  to  enjoy  an  illustrated 
lecture  by  the  same  speaker  simultaneously. 
Both  auditoriums  were  joined  by  a  long-dis- 
tance telephone  line,  at  each  end  of  which  two 
complete  "public  address"  systems  were  at- 
tached, permitting  a  speaker  at  either  place  to 
address  the  two  audiences  simultaneously, 
though  he  spoke  in  a  comparatively  low  voice. 
Stereopticons  and  duplicate  sets  of  slides  were 


provided  and  the  audience  at  both  ends  of  the 
line  had  no  difficulty  in  following  the  entire 
lecture.  A  second  lecture,  delivered  in  Chicago, 
was  heard  in  a  similar  manner  in  both  cities.  1 1 
gave  the  listeners  an  uncanny  feeling  to  hear, 
at  the  end  of  the  lecture,  the  applause  of  first 
one  audience  and  then  the  other. 

But  even  this  wonderful  demonstration  of 
the  practicability  of  joining  audiences  in  various 
parts  of  our  country  by  a  two-way  communica- 
tion system  was  not  enough  to  satisfy  the 
American  Telephone  &  Telegraph  Company, 
who  arranged  it.  An  additional  tap  was 
taken  off  the  wire  connecting  New  York  and 
Chicago  and  by  a  delicate  manipulation  of  the 
circuits,  enough  current  was  drawn  into  the 
company's  broadcasting  station,  WEAF,  in 
New  York  City,  to  actuate  the  modulating 
system  at  that  station.  In  this  manner,  the 
listening  audience  became  much  larger  than 
the  visible  audience.  Enthusiastic  reports 
from  many  parts  of  the  country  were  received. 


A  CHINESE  STUDENT  DETERMINING  TUBE  CHARACTERISTICS  AT  COLUMBIA  UNIVERSITY,  N.  Y. 
Mr.  Shu  S.  Man,  a  graduate  of  Hong  Kong  University,  came  from  China  to  do  advanced  research  work  in  this  country. 
He  is  here  seen  testing  the  amplification  characteristics  of  a  vacuum  tube  under  various  plate  and  grid  voltages 


I  ii II II  1 1 II  III  II II II  IIIIIII  IIIIIIIIIIMII'I  IIHIIII  illlllllllllllHIIIHI'II  IIIIMIIHHII 


i 


'4 


Radio  Broadcast 


OPERATORS  IN  THE  CONTROL  ROOM 

Located  in  the  Engineering  Societies  Building,  New  York  City,  keeping  the  wires  between  New  York 
and  Chicago  working  at  their  best  for  the  audiences,  in  both  cities,  some  nine  hundred  miles  apart 


Picture  to  yourself  a  man  in  his  living  room 
in  Chicago  listening  to  a  lecturer  in  his  own 
city,  the  reproduction  of  the  voice  coming  to 
him  after  a  trip  by  wire  to  New  York  and  by 
ether  back  to  Chicago  in  less  time  than  one's 
thoughts  can  follow  the  process.  This  will 
give  you  a  slight  idea  of  the  possibilities  of  such 
a  means  of  communication.  It  is  quite  likely 
that,  for  the  first  time  in  the  history  of  our 
country,  the  next  President's  inaugural  ad- 
dress will  be  heard  in  every  state  and  most 
of  the  larger  cities  by  a  similar  arrangement 
of  telephone  lines  used  in  conjunction  with 
broadcasting  stations  and  receiving  outfits 
equipped  with  loud  speakers. 

Twelve  More  Men  Owe  their  Lives  to  Radio 

THE  five-masted  schooner  Santino  was 
recently  put  to  the  lowly  task  of  carrying 
coal.  She  was  built  during  the  war  when 
any  respectable  ship  was  at  a  premium,  but  in 
the  after-the-war  slump  it  was  found  that  coal 
cargoes  from  Norfolk  to  New  England  were 
as  much  as  she  could  hope  to  do.  On  her 
second  trip  from  Norfolk  in  this  work  she 


struck  bad  weather  south  of  Nantucket  Light 
and  her  seams  opened  up.  The  war  work  in 
the  shipping  yards  apparently  wasn't  always 
very  well  done.  To  make  her  plight  worse, 
her  pumps  broke  down  (the  men  who  put  them 
in  were  probably  paid  too  much)  and  she  was 
soon  in  a  sinking  condition.  The  twelve  men 
who  manned  her  were  rescued  with  the  help  of 
radio;  and  the  same  signals  which  called  the 
rescuing  vessel  called  the  Coast  Guard  cutter 
Acusbnet,  to  salvage  the  vessel  and  her  cargo  or 
to  destroy  the  wreck. 

Radio  Sets  are  Contraband  in  China 

IT  SEEMS  that  one  political  faction  of  China 
is  afraid  that  radio  may  be  too  powerful 
a  weapon  in  the  hands  of  the  opposition ,  and 
accordingly,  broadcasting  apparatus,  such  as 
we  use  here,  has  been  put  on  the  taboo  list  in 
China.  An  ambitious  American  firm  an- 
nounced that  it  intended  to  inaugurate  a  broad- 
casting service  in  China,  but  evidently  changed 
its  mind  when  the  customs  commissioner  at 
Shanghai  gave  out  the  information  that  all  such 
apparatus  would  be  seized  as  contraband  of  war. 


The  March  of  Radio 


'5 


^  Protecting  Our  Readers  ^ 

DURING  the  unprecedented  demand  for 
receiving  apparatus — especially  broad- 
cast receivers — last  year  and  again 
during  the  present  peak  of  business,  there  has 
been,  and  there  now  is,  a  grand  opportunity  for 
unprincipled  and  uninformed  petty  capitalists 
to  enter  the  radio  business  and,  as  they  them- 
selves express  it,  "make  a  clean-up."  Such  a 
clean-up  is  usually  accompanied  by  a  large  loss 
on  the  part  of  the  victims,  who,  in  the  effort  to 
purchase  a  radio  outfit  and  finding  all  the 
standard  lines  depleted,  are  cajoled  into  pur- 
chasing what  has  come  to  be  called  "bootleg" 
merchandise. 

Just  as  long  as  the  world  rolls  on,  we  are 
going  to  find  people  in  business  who  believe 
it  is  easier  or  preferable  to  earn  their  livelihood 
among  the  folks  of  whom  Barnum  said,  "One 
is  born  every  minute"  than  in  legitimate  enter- 
prise. And  there  will  ever  be  those  gullible 
people  who  will  part  with  their  shekels  to  the 
tune  of  a  suave  talker's  eulogies  on  the  merits 
of  apparatus  that  proves  to  be  practically 
worthless. 

Our  advertising  department  has  adopted  a 
plan  which  may  save  readers  of  Radio  Broad- 
cast from  any  such  loss.  This  is  the  plan  they 
have  outlined: 

We  are  to  place  a  star  in  the  advertising 
space  of  manufacturing  companies  whose 
material  we  know  can  be  absolutely  relied  upon 
to  do  what  is  claimed  for  it.  We  are  taking 
it  upon  ourselves  to  assure  our  readers  that 
material  purchased  from  advertising  carrying 
our  star  is  sold  with  the  assurance  that  if  its 
performance  is  not  as  represented  in  the  adver- 
tising, it  may  be  returned  for  credit.  Products 
of  the  best  quality  may  be  advertised  without  be- 
ing starred,  but  this  is  only  because  they  have 
not  actually  been  tested  by  Radio  Broadcast. 
It  goes  without  saying  that  advertisements  of 
inferior  products  will  find  no  place  whatever 
in  the  magazine. 

We  cannot  undertake  a  general  endorsement 
of  the  merchandise  handled  by  jobbing  or  mail 
order  houses,  although  we  are  quite  confident 
that  our  readers  may  look  for  fair  dealing  from 
any  of  those  who  advertise  with  us.  In  most 
instances  the  equipment  handled  by  these 
houses,  however,  is  already  endorsed  in  the 
manufacturer's  own  advertisements. 

Radio  Broadcast  is  the  product  of  one  of 


AN  ENGLISH  INVESTIGATOR  OF  OUR  BROAD- 
CASTING SITUATION 
Mr.  A.  P.  M.  Fleming,  C.  R.  E.,  England's  representative  at 
the  international  convention  of  the  Institute  of  Electrical 
Engineers  at  Niagara  Falls  said:  "One  of  the  things  we 
have  learned  (from  the  experience  of  the  United  States)  is 
to  avoid  the  establishment  of  innumerable  broadcasting 
stations  with  no  plan  of  cooperation  between  them" 

the  largest  publishing  houses  in  the  country 
— Doubleday,  Page  &  Company.  Country  Life, 
The  World' s  Work,  The  Garden  Magazine,  The 
Health  Builder  and  Short  Stories  are  among  the 
periodicals  it  publishes  in  its  own  plant  at 
Garden  City,  N.  Y.  It  is  the  largest  publishing 
house  in  the  radio  magazine  business,  and  is  in  a 
position  to  accept  or  refuse  the  advertising  of 
any  product  which  it  believes  to  be  unjustly 
represented. 

Naturally,  a  plan  of  this  nature  is  of  great 
benefit  to  our  advertisers,  for  it  enables  the 
readers  of  Radio  Broadcast  to  buy  with 
confidence.  This,  in  turn,  is  helpful  to  our 
advertising  department,  for  reputable  concerns 
appreciate  that  being  represented  in  a  reliable 
periodical  is  a  substantial  asset  to  them.  By 
the  performance  of  this  service,  we  are  in  a 
position  to  cement  even  more  solidly  the 
friendly  feeling  we  already  enjoy  among  our 
readers. 

J.  H.  M. 


amwraiBis»«3re««nraB«miiifinniiiHiiii  hiibwiwhii™ 


A  Single-Tube  Loop  Set  in  a 

Brief-Case 

A  Receiver  That  Weighs  Six  Pounds,  Including  Everything,  and  Offers  the 
Opportunity  for  Interesting  Experiments  on  Trips  and  Vacations.  The 
Average  Enthusiast  Will  Find  It  Neither  Difficult  Nor  Expensive  to  Construct 

By  WALTER  VAN  B.  ROBERTS 

Princeton  University 

We  have  seen  and  laughed  at  all  manner  of  freak  radio  outfits  which  were  supposed  to  be  portable 
and  supposed  to  work,  but  have  refrained  from  describing  them  because  they  seemed  to  us  impractical  and 
sometimes  very  misleading. 

But  the  set  described  in  this  article  has  several  characteristics  which  seem  to  put  it  in  a  class  by  itself: 
it  is  very  light,  very  small,  inexpensive  to  make,  simple  to  operate — and  it  works!  Can  you  imagine  the 
uncanny  feeling  that  comes  over  one  who  holds  a  complete  outfit — batteries,  aerial,  etc. — in  a  brief-case,  with 
nothing  attached  to  it  but  the  phones  and  "nothing  up  his  sleeve,"  and  hears  the  voice  at  a  station  more 
than  three  hundred  miles  away?  In  trying  out  Mr.  Roberts'  receiver,  which  we  borrowed  from  him  and 
took  into  the  country  to  test,  this  very  thing  occurred:  out  here  on  Long  Island,  we  heard  Pittsburgh. 
Our  cover,  this  month,  illustrates  one  entirely  practicable  use  for  this  outfit. — .The  Editor. 


M 


ANY  so-called  portable  sets  of 
spectacularly  small  dimensions 
have  been  given  publicity  from 
time  to  time,  but  most  of  them 
either  require  something  extra 
in  the  way  of  an  aerial,  or  receive  only  from 
stations  very  close  by;  and  if  vacuum  tubes 
and  batteries  are  used,  the  outfit  is  likely  to 
be  too  heavy  to  be  conveniently  portable. 


ZZ'/2V. 


FIG.  I 

The  circuit  which  Mr.  Roberts  uses 


An  example  of  this  is  a  portable  outfit  described 
not  long  ago  in  the  radio  section  of  a  New 
York  newspaper:  the  set  gave  very  good  results 
on  local  stations  and  even  brought  in  such 
distant  stations  as  Havana,  Cuba,  and  Ft. 
Worth,  Texas,  on  favorable  nights.  But,  al- 
though it  was  not  bulky  (measuring  only  1 1  x 
22x5  inches  over  all) ,  it  weighed  twenty  pounds, 
and  hence  began  to  feel  pretty  heavy  after 
being  carried  any  distance  by  hand. 

Recently,  however,  there  has  been  perfected 
a  small  tube,  the  Radiotron  UV-199,  a  sample 
of  which  was  lent  to  the  writer  by  the  Genera! 
Electric  Company  for  experimental  purposes, 
that  requires  only  60  milliamperes  at  3  volts 
to  light  its  filament.  The  UV-199  tube  has 
not  yet  been  put  on  sale,  but  it  will  probably 
be  available  soon.  The  WD-i  1  tube  will  oper- 
ate in  this  circuit,  although  it  draws  more  cur- 
rent from  the  A  battery  and  takes  a  C-battery 
voltage  of  about  4.5.  This  power  can  be  sup- 
plied by  flashlight  cells.  The  interest  shown  in 
the  "suit-case"  set  mentioned  above  indicated 
that  it  would  be  worth  while  to  design  a 
set  of  "brief-case"  size  weighing  about  six 
pounds  and  capable  of  giving  good  clear  day- 
time reception  of  stations  25  to  50  miles  away. 

The  photograph  shows  the  first  model,  a 
one-tube,  super-regenerative  loop  outfit  which 
is  rather  crude  but  which  does  what  it  was 
designed  to  do,  and,  in  addition,  has  given  better 


_ 


\ 


A  Single-Tube  Loop  Set  in  a  Brief-Case 


17 


results  than  expected  with  dis- 
tant stations  on  favorable 
nights.  The  farthest  stations 
heard  so  far  from  New  York  are 
Chicago,  Kansas  City  and 
Davenport,  Iowa.  These  are 
very  faint,  and  although  quite 
clear  at  times,  are  mentioned 
only  to  give  an  idea  of  the 
"freak"  range  of  the  set.  Of 
course,  as  in  the  case  of  all  un- 
usually long-range  reception, 
the  "freak"  part  is  the  great 
distance  that  the  waves  travel 
sometimes  without  becoming  too 
weak  to  detect.  The  receiver 
itself  will  not  pick  up  any  weaker 
signals  at  night  than  in  the  day- 
time; but  longer  distances  are 
possible  simply  because  the  sig- 
nals themselves  are  stronger. 

In  describing  the  operation 
of  the  circuit  shown  in  Fig.  1, 
an  understanding  of  the  principle  of  super- 
regeneration  will  be  assumed.*  The  two 
features  in  which  this  circuit  differs  from 
the  usual  single-tube  super-regenerator  are 
the  use  of  a  plain  Hartley  interruption  fre- 
quency circuit  using  only  one  large  honeycomb 
coil,  and  the  C  battery  so  poled  as  to  make 
the  grid  positive.  When  the  tickler  coil  is 
moved  away  from  the  grid  coil  so  that  there  is 
no  tendency  to  oscillate  at  radio  frequency, 
the  grid  and  plate  potentials  will  be  approxi- 


Set,  batteries, 
the  box  (95  x  1 
turn  loop  is 


VOLTS 
+  45 


+  J5 
5  +  25 

U-l 

S  +15 
a. 

+  5 
0 

-  5 


PLATE 
'POTENTIAL 

"B"  BATTERY 
VOLTAGE 

"G"  BATTERY 
VOLTAGE  \ 

GRID 
"POTENTIAL 

! 


10,000 
FIG.  2 


SECOND 


1 

10,000 


SECOND 


mately  represented  by  the  curves  of  Fig.  2. 
The  plate  potential  is  seen  to  oscillate  about 
the  horizontal  line  representing  the  value 
of  the  battery  voltage  between  plate  and 

*FortunateIy,  however,  it  is  not  necessary  to  know  all 
this  to  build  and  operate  the  kind  of  set  which  Mr.  Roberts 
describes. — The  Editor. 


ALL  HERE 
and  phone  are  within 
35X3  inches).   A  23- 
wound   around  the 
outside 


filament,  while  the  grid  potential  varies  about 
the  C  battery  voltage  between  the  grid  and  fila- 
ment. 

Now  it  can  easily  be  shown  by  experiment 
that  in  a  simple  regenerative  circuit  using  a 
small  value  of  B  battery,  oscillations  can  be 
made  to  occur  more  readily  if  the  value  of  the 
B  battery  is  increased,  while  conversely,  they 
start  less  readily  if  the  plate  potential  (the 
B  battery)  is  decreased.  Another  experiment 
shows  that  oscillations  occur  less  readily  if 
the  potential  of  the  grid  is  made  positive  (by 
putting  in  a  C  Battery)  than  if  the  grid 
potential  is  kept  near  zero.  These  two  facts 
are  enough  to  explain  the  operation  of  this 
super-regenerator.  For  it  can  be  seen  from 
Fig.  2  that  at  the  time  when  the  plate  potential 
is  at  its  lowest  value  the  grid  potential  is  at  its 
greatest  positive  value.  We  have  just  found 
that  both  these  conditions  are  unfavorable  to 
the  occurrence  of  oscillations  in  the  radio- 
frequency  circuit,  and  hence  if  the  tickler  is 
not  brought  up  too  much,  radio-frequency 
oscillations  will  die  out  rather  than  build 
up  during  this  time.  On  the  other  hand, 
when  the  plate  potential  is  at  its  highest  value 
we  have  the  grid  potential  down  near  zero; 
(see  Fig.  2)  and  as  both  these  conditions  are 
favorable,  oscillations  will  start  up  in  the 
radio-frequency  circuit  and  will  have  built  up 
to  a  value  proportional  to  the  strength  of  the 
signal  picked  up  by  the  loop  when  choked  off 


^3 


II I II  II 1 1  1 1  II I  III  III  I  1 1  III  H  II  lllll  PI  Mlllll  I  lllllllltlMMIIITglTTIITMmramM 


18 


Radio  Broadcast 


by  the  recurrence  of  the  unfavorable  condition 
mentioned  above. 

The  reason  that  the  radio-frequency  oscil- 
lations die  out  during  the  unfavorable  period 
is  that  the  grid  is  then  highly  positive  and 
attracts  a  large  number  of  electrons  from  the 
filament,  and  the  energy  expended  in  doing  this 
is  supplied  by  the  radio-frequency  oscillations 
which  thus  quickly  give  up  all  their  energy,  or 
"die  out."  This  will  explain  the  use  of  the 
positive  C  battery  for  tubes  whose  filaments 
give  off  so  few  electrons  that  the  grid  must  be 
kept  more  positive  in  order  to  attract  equal 
numbers  and  hence  produce  the  proper  "  damp- 
ing" effect.    Another  reason  for  using  the 


positive  C  battery  is  that  it  prevents  the  grid 
from  ever  becoming  very  strongly  negative. 
For  making  the  grid  several  volts  negative  is 
equivalent  to  reducing  the  B  battery  a  good 
many  volts,  which  we  cannot  afford  to  do  when 
we  have  already  cut  down  the  B  battery  to  one 
small  225-volt  block  for  the  sake  of  compact- 
ness and  lightness.  The  unusual  location  of 
the  C  battery  is  for  the  purpose  of  making  it  act 
not  only  on  the  grid,  but  also  in  the  plate  cir- 
cuit, on  the  principle  that  "every  little  helps.  " 

Referring  to  Fig.  i,  the  parts  include  a 
loop,  containing  23  turns  of  No.  24  D.  C.  C. 
wire,  wound  round  the  outside  of  the  case  (9^  x 
x  3  inches.    It  might  be  better  to  devise  a 


11 


THE  WORKS 

The  layout  shown  here  may  be  altered  considerably,  since  there  is  plenty  of  surplus  room  in  the  case.  The  numbers 
indicate  the  units  used  as  follows:  1,4  flashlight  cells  for  A  battery,  in  series-parallel;  2,225-volt  B  battery;  3,  UV-199 
bulb  and  socket;  4,  rheostat;  5,  honeycomb  coil  of  1500  turns;  6  and  7,  by-pass  condensers  each  of  .001  capacity;  8,  conden- 
ser in  interrupter  circuit,  .002  mfd.;  9,  phone  by-pass  condenser,  .05  mfd;  10,  phone,  any  type  will  do;  11,  tickler  coil; 
12,  grid  coil;  13,  Dubilier  "Variodon"  (or  any  other  small  condenser);  loop,  23  turns  of  No.  24  wire 


A  Single-Tube  Loop  Set  in  a  Brief-Case 


19 


means  of  supporting  these  wires  inside  the 
cabinet) ;  a  tickler  and  a  grid  coil,  wound  on 
spider-web  forms  2"  inner  diameter  and 
diameter  including  teeth.  19  teeth  are  used 
and  No.  28  D.  C.  C.  wire  is  wound  over  three, 
then  under  three,  etc.,  which  gives  three  times 
as  many  turns  on  the  same  length  of  tooth  as 
the  ordinary  spider-web  winding.  The  wire 
is  wound  on  fairly  tight  and  up  to  within  about 
an  eighth  of  an  inch  of  the  ends  of  the  teeth. 

The  variable  condenser  has  to  be  compact. 
The  one  now  in  use  by  the  writer  is  a  Dubilier 
.0005  mfd.  A  Connecticut  condenser  will 
also  go  in  the  box. 

The  .001  and  .002  mfd.  condensers  are 
Micadons.  None  of  these  values  is  critical, 
the  first  two  being  merely  radio-frequency  by- 
passes while  the  third  determines  the  inter- 
ruption frequency. 

The  1 500-turn  honeycomb  coil  has  to  be 
tapped  at  several  places  in  order  to  determine 
the  best  place.  If  the  wire  from  the  inside 
of  the  coil  is  the  one  connected  to  the  grid,  then 
the  proper  tap  will  be  about  one  third  the  way 
from  the  inner  edge  to  the  outer  edge  of  the 
coil.  As  the  taps  are  very  easy  to  make  by 
prying  up  the  wire  slightly  and  soldering  small 
wires  on,  it  will  be  well  worth  while  to  make 
at  least  six  taps  near  this  point  so  as  to  find 
the  best  by  experiment. 

A  single  Baldwin  receiver  without  head  band 
is  used.  The  phone  by-pass  condenser  is  a  Fed- 
eral (price  fifty  cents).  One  of  large  capacity  is 
used  in  order  to  by-pass  the  interruption  fre- 
quency. The  B  battery  is  a  single  small  22^- 
volt  block,  and  the  A  battery  consists  of  four 
flashlight  cells  in  series-parallel,  giving  three 
volts  and  lasting  longer  than  only  two  cells. 

An  improvement  in  operation  will  be  possible 
when  a  sufficiently  small  rheostat  of  25  ohms 
or  more  can  be  obtained,  so  that  4^  volts  of  A 
battery  can  be  used  (three  flashlight  cells),  and 
as  the  battery  runs  down  the  resistance  can  be 
cut  out.  Fig.  3  shows  the  circuit  in  its  re- 
commended form.  A  sufficient  positive  poten- 
tial for  the  grid  of  a  Radiotron  UV-199  is 
obtained  by  using  the  positive  side  of  the  A 
battery  as  shown. 

In  operating  the  set  only  two  adjustments 
are  required.  The  condenser  is  turned  to  the 
proper  point  while  the  tickler  is  kept  just 
close  enough  to  maintain  the  hissing  sound 
.  characteristic  of  super-regeneration.  When  the 
tickler  is  brought  too  close  the  whole  thing 
suddenly  goes  "dead."    If  you  then  withdraw 


22'/2V. 


FIG.  3 

This  is  the  circuit  which  Mr.  Roberts  recommends.  The 
arrangement  in  Fig.  1,  however,  is  better  for  WD-i  1  tubes. 

the  tickler  somewhat  and  touch  the  grid  with 
your  finger,  the  interruption  frequency  will 
start  up  again.  The  proper  tap  on  the  1500 
turn  coil  need  not  be  changed  after  it  is  once 
found.  It  should  not  be  so  near  the  grid  end 
as  to  let  the  advance  of  the  tickler  kill  the 
interruption  frequency  too  easily,  nor  so  far 
from  the  grid  end  that  the  furthest  advance  of 
the  tickler  will  not  produce  the  proper  hissing. 

No  claim  is  laid  to  any  great  ingenuity  in 
space  saving,  so  that  the  arrangement  of  parts 
will  not  be  dwelt  upon  except  to  note  that  put- 
ting some  of  the  parts  in  the  box  and  some  on 
the  hinged  panel  makes  available  considerably 
more  area,  for  parts  that  are  not  very  high,  than 
mounting  them  directly  on  the  panel.  It  is  prob- 
able that  by  careful ''designing  the  dimensions 
could  be  reduced  to  about  2§  x  9  x  10  inches,  al- 
though it  would  probably  be  difficult  to  reduce 
the  weight  much  below  the  present  six  pounds. 

Such  a  set  as  this  should  be  of  value  to  those 
who  want  to  be  able  to  catch  weather  reports  or 
time  signals  or  special  features  once  in  a  while, 
but  who  do  not  use  radio  enough  to  warrant  the 
trouble  of  aerial  and  ground  installations,  or  the 
expense  and  house  room  of  an  ordinary  loop 
set.  And  it  will  perhaps  interest  also  those 
who  want  to  be  able  to  carry  a  complete 
receiver — containing  within  the  four  walls  of  a 
small  thin  box  everything  including  phones  and 
batteries — from  one  place  to  another.  With  it, 
they  can  listen  from  an  auto  or  boat,  for 
instance,  or  at  a  camp — in  fact,  wherever  their 
vacation-time  travels  may  take  them. 


Confessions  of  an  Unmade  Man 


"Beware!"  Cries  This  Miserable  Wretch  as  He  Goes  Under  for  the  Third  Time 

By  R.  0.  JASPERSON 


A  YEAR  ago  I  was  a  sober,  respected 
/%     citizen,  loved  of  my  family,  wel- 
/  %    come  in  the  homes  of  my  friends. 
I      %  1  paid  my  bills  promptly,  kept  my 
^       ^  walks  clean  in  winter  and  my  lawn 
mowed  in  summer.    In  short  1  was,  as  you 
might  say,  a  substantial  member  of  that  class  of 
citizens  who  are  the  bone  and  sinew  of  our 
nation. 

Look  at  me  to-day.  I  am  no  longer  sober. 
Once  1  could  pass  by  where  the  deadly  stuff  is 
sold  and  never  bat  an  eye.  To-day,  alas,  my 
feet  carry  me  into  the  open  doors  where  tempta- 
tion lurks.  I  am  no  longer  master  of  myself. 
Gone  is  the  respected  citizen.    No  longer  do  my 


RADIO 
SUPPLI 


GONE  IS  THE  RESPECTED  CITIZEN 
Once  I  could  pass  by  where  the  deadly  stuff  is 
sold  and  never  bat  an  eye.  To-day,  alas,  my 
feet  carry  me  into  the  open  doors  where  tempta- 
tion lurks:  1  am  no  longer  strong  enough  to 
"take  it  or  leave  it  alone" 


friends  welcome  me;  they  shun  me.  My  family 
is  disgusted  with  me,  my  bills  are  unpaid,  my 
walks  are  not  shoveled,  and  my  position  is  in 
danger. 

My  downfall  has  been  rapid.  A  week  before 
Christmas,  little  did  I  dream  that  such  a  change 
could  take  place.  When  I  first  heard  the 
seductive  whisper  of  the  tempter  and  1  yielded, 
knowing  full  well  the  fate  that  had  overtaken 
my  friends,  I  felt  I  was  strong  enough  to  "take 
it  or  leave  it  alone. " 

That  was  at  Christmas  time.  1  shall  always 
look  back  upon  that  happy  season  as  the  begin- 
ning of  my  ruin. 

You  see,  it  was  like  this.  A  friend,  yes  it  was 
a  friend  who  started  me  on  the  downward 
path,  asked  me  to  go  with  him  to  a  place  where 
they  sell  radio  parts  and  sets.  He  had  just 
been  paid  and  there  was  a  gleam  in  his  eye. 
He  hadn't  bought  so  much  as  a  piece  of  spaghetti 
for  three  days  and  I  could  see  that  it  was  useless 
to  attempt  to  restrain  him. 

So  I  went  with  him.  It  was  not  a  gilded  den, 
but  in  spite  of  the  crudeness  of  the  furnishings, 
they  had  the  stuff  to  sell.  There  it  lay  exposed 
to  the  greedy  eyes  of  the  poor  wretches  who  were 
spending  their  hard  earned  cash  for  "parts." 

My  friend  ordered  a  variable  condenser  for 
himself  and  knowing  that  I  didn't  indulge, 
asked  the  bart — 1  mean  the  clerk — toshow  me  a 
"set,"  just  a  cheap  little  set  costing  $io,  while 
he  poured  tempting  words  into  my  ear. 

"You  can  get  WJZ,  and  KDKA,  and  WOR 
with  this  set."  Now  I'm  telling  you.  Just 
think  of  it,  all  those  beautiful  concerts,  speeches, 
and  think  of  the  prize  fights,  "blow  for  blow" 
— those  were  his  exact  words — and  last  night 
1  got  Cuba  ..." 

"Cuba,  did  you  say,  Cuba    .    .    .  ?" 

"  Yes,  I  got  Cuba,  but  you  understand,  not 
on  this  set.  No,  I've  got  honeycomb  coils 
and  two  stages  of  radio  and  two  of  audio,  and 
next  week  I'm  going  to  get  a  loud  speaker." 

I  might  have  known  from  his  raving  how  bad 
they  get  when  once  they  fall,  but  I  was  heedless. 

"  Blow  for  blow. "  Those  words  kept  ringing 
through  my  head.    "Concerts"  and  every- 


Confessions  of  an  Unmade  Man 


thing.    Only  $10.  WJZ, 
WGY,  KDKA    .  . 

Gentle  reader,  I  blush  to 
tell  it,  but  the  temptation 
was  too  great.  I  struggled, 
but  struggled  in  vain.  1 
bought  the  little  $10  set, 
but  with  the  strong  resolu- 
tion that  it  would  be  all.  I 
would  show  them  I  could 
take  it  or  leave  it  alone. 

I  don't  think  my  good 
wife  realized  how  she  con- 
tributed to  my  failure  to 
stick  to  my  resolution  to 
be  strictly  temperate.  As 
I  look  back,  I  see  how  her 
suggestion  that  it  would  be 
nice  if  we  could  both  listen 
in  at  the  same  time  led 
to  my  future  excesses.  I 
bought   an  extra  pair  of 
phones,  a  little  matter  of  $7,  and  a  few  nights 
later  when  company  came  to  listen  to  our 
radio  set,  wife  suggested  we  ought  to  have 
one  of  those  horns  so  everybody  could  listen. 

I  threw  caution  to  the  winds  and  proceeded 
to  read  all  the  magazines  I  could  get  on  the 
subject.  My  favorite  daily  newspaper  did  not 
publish  enough  radio  information  so  1  changed 
to  one  that  must  be  owned  by  some  fiend 
judging  from  the  amount  of  space  devoted  to 
the  subject.  All  the  magazines  except  those 
dealing  with  radio  lie  unopened  and  unread 
upon  my  library  table. 

Before  prohibition  when  a  fellow  indulged,  it 
was  hiccups.  Now  it  is  hook-ups.  My  pockets 
are  full  of  them.  1  bought  a  book  on  hook-ups 
and  with  the  words  of  friend  wife  ringing  in  my 
ears,  1  sought  more  volume,  I  craved  distance, 
I  yearned  for  selectivity. 

From  the  maze  of  hook-ups  I  selected  one 
that  looked  modest  a  id  easy  to  master.  I 
bought  the  parts,  some  of  the  parts,  I  should 
say,  and  abandoned  myself  to  the  seductive 
undertaking. 

My  noon  hours  were  spent  in  radio  shops 
whither  I  went  to  get  information  about  grid 
leaks  and  variometers.  Always  1  bought 
more  parts. 

The  office  boy,  also  an  addict,  discovered  my 
secret.  The  size  and  shape  of  the  many 
packages  I  brought  in  each  day  betrayed  me. 
He  recognized  them  and  one  day  came  to  me 
with  a  hook-up  and  asked  my  opinion.    It  was 


THE  OFFICE  BOY  AND  I  ARE  COMPANIONS  IN  CRIME 
We  sneak  off  to  the  seclusion  of  the  stock  room  to  exchange  hook-ups.    Once  the 


office  boy's  opinions  on  any  subject  were  of  no  interest  to  me. 

seek  his  advice 


Now  I  eagerly 


a  subtle  thing  to  do 


Now,  the  office  boy  and  I 
sneak  off  to  the  seclusion  of  the  stock  room  to 
exchange  hook-ups.  We  are  companions  in 
crime.  Once  the  office  boy's  opinions  on  any 
subject  were  of  no  interest  to  me.  Now  I 
eagerly  seek  his  advice. 

Even  without  taking  time  to  eat  lunch,  I 
find  I  have  difficulty  in  getting  back  to  the 
office  at  noort.  The  office  boy  is  helping  me 
buy  parts.  Yesterday  he  knew  where  he  could 
get  tubes  at  half  price.  I  drew  my  last  dollars 
out  of  the  bank  and  dispatched  him  post  haste 
to  get  three  of  them. 

Next  week  I  must  get  a  certain  battery.  The 
grocer  and  butcher  will  have  to  wait.  }  must 
have  that  battery. 

Where  will  it  end?  It  can't  go  on.  If  I 
knew  of  a  cure  I  would  take  it.  I  have  tried 
to  limit  myself  to  a  definite  sum  weekly,  but 
resolutions  are  of  no  avail.  My  will  power  is 
gone.  Money  means  nothing  to  me  except  a 
means  of  gratifying  my  consuming  craving  for 
parts. 

There  ought  to  be  a  law  against  exposing 
radio  parts  for  sale.  It  is  putting  temptation 
into  the  way  of  the  slave  to  radio.  No  effort 
is  made  to  screen  the  shops  where  radio  addicts 
congregate.  The  traffic  goes  on  openly  in 
full  view  of  the  young  and  impressionable. 

Even  mere  boys  are  among  the  worst  cases. 
I  have  seen  mere  babes  of  no  more  than  nine 
or  ten  rush  wildly  into  a  radio  shop  and  demand 
three  honeycomb  coils  and  a  vernier  rheostat, 


22 


Radio  Broadcast 


throwing  the  money  madly  at  the  clerk  and 
dashing  away  with  the  parts  clasped  to  their 
eager  breasts.  It's  a  sad  commentary  on  our 
American  institutions.  When  you  protest,  the 
sad  eyed  clerk  simply  smiles  and  says,  "We 
might  as  well  take  it  from  the  children.  If 
they  don't  spend  it,  their  fathers  will.  " 

The  other  day  I  saw  a  well  dressed  man 
sitting  in  a  radio  shop  in  deep  thought.  His 
clothes  were  still  in  fairly  good  shape,  although 
I  felt  that  he  had  seen  better  days.  He  looked 
up  as  I  passed  and  he  must  have  recognized 
in  me  a  kindred  spirit,  for  he  said,  "  1  simply 
can't  make  it  out.  Nobody  seems  to  be  able 
to  help  me." 

"Perhaps  I  can,"  I  said,  for  I  felt  sorry  for 
him. 

Then  he  told  me  his  story.  "  1  have  been 
addicted  to  the  habit  two  years.  1  have  built 
twenty  sets  and  used  every  kind  of  hook-up 
from  a  crystal  to  a  five-tube  set  with  indoor 
aerial.  I  have  spent  most  of  my  money  and 
1  thought  I  was  through,  but  a  few  nights  ago 
I  was  adjusting  mv  variable  grid  leak  when  the 
darn  set  spoke  up  as  1  never  heard  it  before. 
I  tried  laying  a  screw  driver  across  the 
terminal  and  the  knob,  and  it  fairly  shouted. 
1  cut  a  piece  of  zinc  about  the  size  of  the  screw 
driver  and  it  worked  still  better.  Then  I 
began  to  experiment,  cutting  larger  and  larger 
pieces  of  zinc,  each  time  getting  the  tone  louder 
and  clearer.  Then  I  ran  out  of  zinc  until  I  re- 
membe redan  oldzinc  bathtubover  onthe  dump. 
1  got  that  and  was  bringing  it  home  when 


my  wife  introduced  me  to  a  gentleman  who  she 
said  was  to  take  care  of  me.  He's  out  there 
now,  see  him?  He's  waiting  for  me  to  come 
out  and  take  me  back  to  the  sanitarium.  Well, 
I  don't  care,  only  1  wish  someone  would  tell  me 
what  made  my  set  speak  up  like  that." 

1  was  unnerved.  I  realized  what  I  was  com- 
ing to.  A  few  short  weeks  ago,  all  unmindful  of 
danger,  1  embarked  upon  my  career  of  debauch- 
ery and  now  1  am  without  hope.  All  about  me 
1  see  the  bright,  promising  young  men  who  will 
soon  be  like  myself,  ruined. 

Go  west,  young  man,  go  west — but  no,  it's 
as  bad  out  there  as  it  is  here.  But,  at  least, 
stop  before  it  is  too  late.  When  temptation 
comes,  and  you  have  once  given  way  to  it,  re- 
member there  is  no  cure. 

Why  do  1  pen  these  words?  I  would  spare 
you  the  sight  that  met  my  eyes  last  night. 
Finding  1  needed  a  couple  of  binding  posts,  1 
stole  out  of  the  house  to  a  low  radio  shop  around 
the  corner  which  keeps  open  all  night.  There 
was  the  usual  crowd  of  men  and  boys,  but  what 
especially  pained  me  was  the  sight  of  an  un- 
shaven man  leaning  heavily  over  a  showcase 
studying  the  display  of  "parts."  Tugging  at 
his  arm  was  a  wan  little  girl  who  was  singing  a 
song  1  had  heard  many  years  before,  "  Father, 
dear  father,  come  home  with  me  now,  the  clock 
in  the  steeple  strikesone.  "  But  the  man  shoved 
her  away  with  a  muttered  curse. 

It  was  too  much.  1  resolved  to  devote  my- 
self to  saving  others  from  the  fate  that  had 
overtaken  me.    May  these  lines  help  


Radio  as  a  Rent  Inducement 

By  ALLISON  EURAY 


4k  N     ENTERPRISING     real  estate 
f\     firm  in  St.  Louis,  Mo.  has  conceived 
/  \    the  idea  of  equipping  each  one  of  the 
/     %  fifty-four  apartments  in  the  Garden 
Court  Apartments,  located  at  5330 
Delmar  boulevard,  with  a  loud  speaker  (oper- 
ated from  a  central  receiving  station),  as  an 
extra  inducement  for  the  renting  of  them.  No 
charge  is  made  for  the  radio  service  which  goes 
in  with  the  rent. 
The  apartment  house  has  a  central  receiving 


station  with  an  outside  aerial,  and  in  each 
apartment  there  is  a  loud  speaker  which  the 
tenant  can  connect  or  disconnect  with  a  plug. 

In  a  trial  recently  held,  the  receiving  station 
has  "picked  up"  Kansas  City,  Atlanta,  Pitts- 
burg, Waco,  and  other  Texas  points.  However, 
information  as  to  how  the  situation  will  be 
handled,  when  a  half-dozen  of  the  tenants  get 
to  arguing  with  the  landlord  as  to  which 
station  is  to  be  listened  in  on,  has  not  been 
divulged. 


The  "Ham"  Set  of  an  Old  Ship 

Operator 

Amateur  Station  2ABM,  at  New  Rochelle,  N.  Y.,  Resembles  a  Commercial 
Station  in  Many  Ways.    Remote  Control  is  One  of  Its  Outstanding  Features 

By  ZEH  BOUCK 

Many  a  fellow  has  taken  up  radio  to  enable  him  to  have  a  taste  of  travel  and  adventure.  Several 
years  later,  when  he  has  settled  down,  he  often  finds  that  he  cannot  keep  his  hand  off  a  key  or  the  receivers 
off  his  ears.  The  kinks  learned  as  commercial  operators  are  being  used  by  amateurs  like  Mr.  Parsons  in 
home  stations  throughout  the  country. — The  Editor. 


SOME  weeks  ago,  two  elderly  gentlemen, 
both  broadcast  enthusiasts,  were 
standing  at  a  corner  in  New  Rochelle, 
I  N.  Y.,  exchanging  the  time  of  day  and, 
incidentally,  their 
achievements  in  radio  tele- 
phone reception.  A  short 
distance  away,  rising  high 
above  neighboring  build- 
ings, was  a  wireless  tower, 
which,  catching  the  eye  of 
one  of  the  gentlemen, 
caused  him  to  exclaim: 

"Great  Scott!  That's 
some  tower.  The  chap  who 
owns  that  must  have  a 
wonderful  station!" 

The  second  man  snorted 
disgustedly.  He  had  expe- 
rienced some  interference, 
which,  rightly  or  wrongly, 
he  blamed  on  that  particu- 
lar station.  "Good  station 
nothing!"  he  replied.  "Why, 
he's  only  an  amateur." 

The  gentleman  who  spoke 
so  vehemently  knew  little 
about  amateurs,  in  general 
or  in  particular,  and  nothing 
about  the  equipment  of  the 
station  in  question. 

This  tower  is  visible 
many  blocks  away,  and  is, 
perhaps,  the  most  spec- 
tacular adjunct  to  station 
2ABM, owned  and  operated 
by  Mr.  Fred  Parsons.  The 
huge  framework  is  built  one 
quarter  of  two  by  two-inch 
spruce,  and  three  quarters 


of  the  resourcefulness  and  ingenuity  of  the 
amateur.  It  is  all  the  more  amazing  when 
it  is  considered  that  it  went  up  almost  en- 
tirely at  night  and  without  plans  except  for 


THE    IOO-FOOT  TOWER  AT  2ABM 


ih'iH  urn  ii  m Mi i  ii ■!' 1 11  m  ii  ii m iiiiiiiiiiiiiaiiiiiiiiiiiiiiimpiiMiiPiiiiiniii 


1 


24 


Radio  Broadcast 


the  pre-determination  that  the  base  should 
be  ah  equilateral  triangle  with  twelve  foot 
sides,  and  that  it  should  taper  so  that  the 
'top,  seventy-five  feet  high,  would  form  a 
smaller  triangle  three  feet  on  a  side.  The 
number  and  positions  of -the  crosspieces  were 
also  approximately  calculated.  The  tower 
was  built  up  from  the  unreenforced  earth,  the 
foundations  being  laid  after  the  framework 
was  completed!  These  consist  of  several 
thousand  pounds  of  concrete  poured  into  three 
holes  dug  around  the  base  to  which  the  up- 
rights are  anchored.  The  tower,  though  prac- 
tically self-supporting,  is  additionally  safe- 
guarded against  strong  winds  by  guy  wires. 
The  mast  on  the  top  of  the  tower  rises  twenty- 
five  feet  above  the  platform,  giving  a  total 
height  of  one  hundred  feet. 

The  transmitting  antenna  consists  of  four 
wires  which  fall  almost  vertically  from  the 
top  mast  to  the  roof  of  the  shack,  which  reduces 
the  actual  lead-in  to  a  few  feet,  and  forms  an 
aerial  of  the  most  efficient  radiating  type 
(vertical). 

The  outdoor  loud-speaker  shown  below  is 
operated  from  the  power  amplifier,  which  was 
especially  constructed  for  the  rebroadcasting 
on  sound  waves  of  special  events,  such  as 


THIS  OUTDOOR  LOUD  SPEAKER  CAN  BE  HEARD  A  MILE  AWAY 
Special  events  such  as  election  returns,  play-by-play  ball  games  and  blow-by-  blow 
prize  fights  are  re-broadcasted  on  sound  waves,  the  loud  speaker  being  hoisted  up 
on  the  antenna  tower 


prize  fights,  election  returns  and  the  World 
Series  baseball  games.  It  is  built  entirely 
of  wood,  five  feet  long  with  a  three-foot  square 
"bell."  The  standard  Western  Electric  loud- 
speaker unit  clamps  to  the  rear  end.  Eleva- 
ted on  the  antenna  tower,  this  mammoth 
loud-talker  can  be  heard  over  a  mile  away, 
and  clearly  understood  at  half  that  distance. 

The  station  proper  occupies  the  top  floor 
of  the  garage  shown  at  the  base  of  the  tower 
in  the  first  illustration.  Like  the  majority  of 
efficient  stations,  the  apparatus  is,  for  the 
greater  part,  operated  by  remote  control. 
The  operating  table,  from  which  the  function- 
ing of  the  receiver  and  transmitter  is  con- 
trolled, is  shown  on  the  opposite  page.  Various 
high-current  circuits  are  opened  and  closed 
by  relays  operated  by  the  bank  of  keys  on  the 
panel  of  the  left  centre  cabinet.  Among  the 
operations  effected  from  this  board  are  stop- 
ping and  starting  the  rotary  spark  gap,  closing 
the  power  line  to  the  transmitting  transformer, 
transferring  the  key  from  the  wireless  to  the 
land-line  sounder,  and  operating  the  N  A  A 
light,  which  flashes  from  an  illuminated  wall 
map  with  the  dots  of  the  time  signals.  This 
last  is  accomplished  by  adjusting  the  grid  bias 
on  the  final  stage  of  power  amplification,  so  that 
the  plate  consumption  of 
the  tube,  when  quiescent, 
is  zero,  while  the  signals 
from  Arlington  will  so  un- 
balance the  circuit,  that  the 
bulb  will  draw  some  fifty 
milliamperes.  This  is  suffi- 
cient to  actuate  an  espe- 
cially designed  high-resis- 
tance relay  which  closes  a 
local  battery  circuit  to  the 
lamp.  (This  device  could 
well  be  applied  to  tape 
recording  instruments  to 
facilitate  the  deciphering  of 
code,  as  well  as  other  in- 
teresting experiments  in 
telemechanics.  It  might  be 
necessary  to  reverse  the  con- 
nections to  the  secondary 
of  the  last  amplifying  trans- 
former, in  order  that  the 
grid  be  charged  positively. 
The  plate  voltage  should  be 
above  two  hundred,  prefer- 
ably three  hundred  and 
fifty,  and  the  grid  bias  on 


The  "Ham"  Set  of  an  Old  Ship  Operator 


25 


MR.  FRED  PARSONS,  2ABM,  AT  HIS  STATION  IN  NEW  ROCHELLE,  N.  Y. 


some  tubes  may  be  as  high  as  one  hundred 
volts.  A  five-watt  power  tube  should  be  used 
in  the  last  step.) 

To  the  extreme  left  in  the  picture  of  the 
operating  room  (above)  is  a  land-line  instru- 
ment, for  Mr.  Parsons  is  an  old  timer  whose 
experience  dates  back  to  the  days  of  Morse. 
The  receiver  to  the  left  is  a  Paragon  RA-10, 
with  antenna  series  condenser,  and  detector 
and  two  steps  mounted  directly  above.  Two 
aerials  are  used  individually  for  reception  and 
transmission,  the  switch  above  the  control-box 
disconnecting  the  single-wire  receiving  antenna 
from  the  set,  protecting  the  delicate  instruments 
from  high  potential  surges.  The  cabinet  to 
the  centre  right,  originally  a  detector-amplifier 
for  the  honeycomb  long-wave  receiver  next  to  it, 
is  now  common  to  both  sets,  a  plug  and  jack 
arrangement  permitting  various  changes  of 
input  and  output.  The  telephone  is  an  ex- 
tension to  that  installed  in  the  living  quarters, 
which,  however,  is  used  only  when  a  red  signal 


light  does  not  indicate  that  the  receiver  is 
removed  on  the  house  phone.  Similar  red  and 
green  lights,  at  different  parts  of  the  station, 
indicate  the  functioning  of  various  circuits. 
On  the  side  of  the  operating  table,  arranged 
according  to  the  practiceof  commercial  stations, 
are  in-and-out-going  message  blanks,  2ABM 
being  an  official  relay  station,  covering  a  wide 
territory  between  the  Mississippi  and  the 
Atlantic  Ocean.  The  typewriter  further  fa- 
cilitates and  systematizes  the  handling  of 
traffic. 

The  photo  on  page  27  shows  the  receiving 
high-voltage  equipment  and  the  connection 
rack  similar  to  that  in  station  2FZ  which  was 
described  in  last  month's  Radio  Broadcast. 
Below  the  land-line  telegraph  instrument  is 
the  B  battery  box  with  the  side  removed,  show- 
ing the  battery  high-voltagearrangement,  which 
consists,  for  the  greater  part,  of  flashlight 
batteries.  This  system  has  an  advantage  over 
the  block  battery  in  that  the  dead  units,  with 


26 


Radio  Broadcast 


their  material  resistance,  may  be  cut  out  of 
circuit. 

The  stove,  reminiscent  of  the  snowbound 
shacks  of  Marconi  and  Fessenden  in  the  pioneer 
days,  is  a  useful  piece  of  apparatus  on  cold  winter 
nights,  and  is  worthy  of  its  position  in  the  fore- 
ground of  the  picture. 

The  panel  just  to  the  left  of  the  stove-pipe  is 
the  high-voltage  switchboard  for  the  power 
amplifier,  which  is  fed  at  three  hundred  and 
fifty  volts  from  a  dynamotor  suspended  in 
back  of  the  panel.  The  dynamotor  is  operated 
from  the  storage  batteries  shown  in  the  picture 
below,  and  the  output  is  perfectly  filtered,  or 
the  commutator  hum  smoothed  out,  by  con- 
densers and  choke  coils.  Between  the  uprights 
of  the  connection  rack  are  relays  forming  part 
of  the  remote  control  system. 

In  the  picture  below,  the  power  and  battery- 
charging  switch-boards  are  shown,  respectively, 
from  left  to  right.    The  power  board  was 


MR.  PARSONS  AT  THE  POWER  SWITCHBOARD 


purposely  constructed  with  adequate  space  for 
expansion.  The  relays  in  the  upper  portion 
close  the  circuits  to  the  power  transformer  and 
rotary  spark  gap,  a  double  operation  con- 
trolled by  a  single  relay,  while  the  other  func- 
tions as  a  key,  following  the  dots  and  dashes 
of  the  light  Morse  instrument  on  the  operat- 
ing table.  Another  addition  to  the  remote 
control  system  which  will  be  effected  in  the 
near  future,  is  a  time  element  relay,  which, 
operating  independently  of  the  rotary  start- 
ing relay,  will  close  the  circuit  to  the  trans- 
former a  few  seconds  after  the  starting  key  is 
depressed.  This  will  make  it  impossible  to 
transmit  until  sufficient  time  has  elapsed  for 
the  spark  gap  to  gain  a  safe  operating  speed, 
a  precaution  that  is  hoped  will  lessen  the  reg- 
ularity with  which  condensers  are  blown  at 
this  station.  The  four-pole  switch  cuts  off  all 
power  to  the  shack,  including  lights. 

The  charging  panel  consists  of  the  necessary 
switches  controlling  the 
charge  and  discharge  of  the 
various  batteries,  meters 
registering  voltage  and 
current,  necessary  fuses, 
and  the  magnetic  rectifier 
at  the  top  of  the  panel. 

The  transmitter,  as  has 
been  implied,  is  a  spark  set, 
Mr.  Parsons  being  true 
to  the  old  days  that  are 
symbolized  in  a  booming 
gap.  The  transformer,  an 
open  core  affair,  is  partially 
of  home  construction,  it 
being  a  combination  of  the 
secondary  of  an  eight-inch 
spark-coil  slipped  over  a 
primary  wound  to  consume 
one  K.  W.  The  secondary 
potential,  judging  from  the 
spark  and  blown  con- 
densers, is  in  the  neighbor- 
hood of  fifty  thousand 
volts.  The  transmitter  is 
mounted  in  an  especially 
constructed  cupboard,  the 
door  of  which  is  flush  with 
the  wall,  an  arrangement 
that  effectually  silences  the 
roar  of  the  gap. 

Following  the  nation- 
wide custom  of  the  genuine 
amateur,  in  deference  to 


The  "Ham"  Set  of  an  Old  Ship  Operator 


27' 


ANOTHER  VIEW  OF  THE  OPERATING  ROOM 
Showing  the  connection  rack  (at  left),  and  the  high-voltage  B  battery  supply  (at  right  of  stove)  consisting  mainly 
of  flashlight  batteries.    On  cold  winter  nights  the  stove  is  as  important  a  piece  of  apparatus  as  any  in  the  room 


the  BCL  (broadcast  listener),  the  transmitter  at 
station  2ABM  is  silent  between  seven  and 
ten  thirty  p.  m.,  excepting  when  operation  is 
justified  by  some  unusual  necessity. 

From  the  ship's  clock  on  the  wall  to  the  port 
holes  with  which  the  windows  are  being  re- 
placed, the  shack  at  2ABM  is  reminiscent  of  the 
commercial  experience  that  goes  into  the  make- 
up of  many  amateurs. 

Mr.  Parsons  operated  many  years  ago  on  the 
Pole  Star  plying  between  Portland,  Maine,  and 
New  York.  Irving  Vermilyea,  one  of  the  old- 
est of  the  old-timers,  was  his  companion  opera- 
tor on  the  run.  However,  the  radio  careers 
of  these  gentlemen,  as  far  as  the  Pole  Star  is 
concerned,  were  terminated  somewhat  abruptly 
in  1909,  by  an  altercation  between  the  wireless 
operators  and  the  captain.  The  disagreement, 
whatever  it  was,  came  to  a  head  on  the  home- 
ward trip  and  Sparks,  first  and  second,  deter- 
mined to  sever  connections  between  themselves 


and  the  good  ship  Pole  Star  when  they  reached 
New  York.  After  leaving  the  Pole  Star,  Mr. 
Parsons  forsook  the  commercial  game,  and 
returned  to  his  amateur  station,  then,  long 
before  the  days  of  radio  legislation,  working 
on  eight  hundred  meters.  However,  the  lure 
of  the  profession  was  not  dampened  with  Mr. 
Vermilyea,  who,  following  it  for  a  time  on  sea, 
and  then  on  land,  rose  high  in  the  game. 
Shortly  before  the  war  he  was  superintendent 
of  the  old  South  Wellfleet  station,  and  is  now 
manager  of  the  transatlantic  station  at  Marion, 
Massachusetts.  But  his  greatest  boast  (if 
honest  and  deserved  self-appreciation  can  be 
called  a  boast)  is  not  of  his  commercial  achieve- 
ments, or  even  his  peer  of  present  day  amateur 
stations,  iZE,  but  goes  far  back  to  the  days 
preceding  the  Pole  Star,  when  he  was,  without 
a  dissenting  claim,  one  of  the  first  amateurs  in 
the  world ! 

Vermilyea's  first  stations,  when  he  signed 


28 


Radio  Broadcast 


"VN,"  were  the  inevitable  outcome  of  his  im- 
mortal private  telegraph  line,  that  ran,  with  as 
much  system  as  the  streets  of  Greenwich  Vil- 
lage, about  the  city  of  Mt.  Vernon.  There  were 
forty  or  fifty  "  subscribers. "  Juice  for  the  line 
was  originally  furnished  from  some  hundreds  of 
gravity  cells  in  VN's  cellar;  and  at  regular 
meetings  of  the  "  subscribers, "  the  hat  was 
passed,  soliciting  funds  for  the  purchase  of 
copper  sulphate.  Things  finally  came  to  such 
a  pass  that  the  accumulation  of  glassware  and 
blue  vitriol  was  appalling,  and  it  was  then  that 
the  audacity  and  resourcefulness  that  made  and 
kept  VN  an  amateur  came  to  his  rescue.  In- 


spired one  morning,  he  ran  what  was  ap- 
parently a  telephone  line  from  his  house  to 
a  bona  fide  pole;  and  from  there,  in  a  perfect 
imitation  of  the  genuine  article,  it  continued  for 
some  blocks,  or  until  what  VN  considered  was 
a  safe  distance  from  headquarters.  Finally  it 
crossed  to  a  pole  supporting  the  power  feed 
to  the  Mount  Vernon  trolley  line!  Carefully 
hidden  in  a  puttied  up  crack,  it  tapped  the 
five  hundred  and  fifty  volts,  and  for  five 
years  the  miniature  Western  Union  was  amply 
supplied  with  current.  It  is  not  on  record 
that  the  tax  for  copper  sulphate  was  discon- 
tinued. 


The  Tuning  Troubles  of  Messrs.  Gallagher 

and  Shean 

(With  Apologies  to  those  Famous  Men) 
As  Sprung  on  the  Second  District  Amateurs  at  Their  Recent  Annual  Banquet 
By  A.  G.  CLARK,  2  C  N  T 

Of  the  RIDGE  WOOD  RADIO  CLUB 


Oh  Mister  Gallagher,  Oh  Mister  Gallagher, 
1  was  listening  on  the  radio  last  night, 
But  an  amateur  quite  near  seemed  to  like  to 
interfere, 

So  I'm  going  to  kick  and  have  him  closed  up 
tight. 

Oh  Mister  Shean,  Oh  Mister  Shean, 
In  the  radio  game  I  see  you're  pretty  green; 
As  they  say  in  gay  Paree,  what  an  animal  you'd 
be  

What,  an  air-hog,  Mister  Gallagher? 
No,  a  jackass,  Mister  Shean! 

Oh  Mister  Gallagher,  Oh  Mister  Gallagher, 
Now  I  don't  see  why  you  put  the  blame  on 

me, 

Everywhere  I  turn  my  knob  I  can  hear  the 

noisy  slob, 
So  it's  not  my  fault  at  all  as  you  can  see. 
Oh  Mister  Shean,  Oh  Mister  Shean, 
You  are  up  against  a  problem  what  I  mean, 
But  there's  something  you  can  get  that  will  cut 

him  out  you  bet  

An  injunction,  Mister  Gallagher? 
No,  a  tuner,  Mister  Shean! 


Oh  Mister  Gallagher,  Oh  Mister  Gallagher, 
Interference  is  no  more  I  hear  them  boast, 
Cause  a  guy  named  Schnell  has  said  that  the 

old  zink  spark  is  dead  

When  the  tube  came  in  the  spark  gave  up  the 

ghost. 

Oh  Mister  Shean,  Oh  Mister  Shean, 
I  can't  get  the  situation  through  my  bean, 
1  must  ask  Sir  Conan  Doyle  for  when  I  burn 
the  midnight  oil  

You  hear  spirits,  Mister  Gallagher? 

No — spark  sets,  Mister  Shean! 

Oh  Mister  Gallagher,  Oh  Mister  Gallagher, 
Station  20M  is  just  a  mile  away, 
1  can  recognize  his  call  but  can't  tune  him  out 
at  all, 

Though  he's  on  two  hundred  sharp  I  hear  them 
say. 

Oh  Mister  Shean,  Oh  Mister  Shean, 
If  you  hear  him  high  and  low  and  in  between, 
That  "200"  is  a  fraud,  why  he's  on  "180 
broad!" 

Is  that  lawful,  Mister  Gallagher? 
No,  it's  awful,  Mister  Shean ! 


Transmitting  and  Receiving  with  the 
Same  One-Tube  Set 


By  FREDERIC  W.  PROCTER 


THERE  has  been  a  need  among  radio 
enthusiasts  for  a  combined  trans- 
mitter and  receiver  of  low  power  that 
could  be  placed,  complete,  in  a  single 
cabinet  of  medium  size,  and  easily 
carried  about.  Until  now,  few  instruments  of 
this  type  has  been  placed  at  the  amateur's 
disposal,  and  it  is  likely  that  the  one  here  de- 
scribed will  appeal,  because  of  its  extreme  sim- 
plicity, to  those  who  desire  a  transmitting  and 
receiving  set  combined  in  one  unit. 

In  this  instrument,  a  single  tube  is  used  for 
both  sending  (telegraphy)  and  receiving  (tel- 
egraphy or  speech),  and  it  is  advisable  to  secure 
a  tube  that  does  not  need  too  critical  an  adjust- 
ment of  the  filament  when  receiving,  as  it 
would  be  impossible  to  obtain  satisfactory  re- 
sults in  a  circuit  in  which  the  change  from  trans- 


mission to  reception  depends  only  on  the 
position  of  a  telegraph  key.  This  : key  must 
have  two  contacts,  making  it  possible  to 
operate  in  two  circuits,  since  in  the  up  or  off 
position  it  must  make  contact  to  close  the 
receiving  circuit  and  in  the  down  position  form 
the  dots  and  dashes  of  the  code.  The  placing 
of  the  key  in  this  combined  circuit  is  unique 
and  makes  possible  the  dual  work  performed. 
It  will  be  seen  from  the  following  explanation 
that  when  the  key  is  in  the  up  position,  during 
code  transmission,  the  circuit  is  held  open  for  re- 
ception. Another  advantage  of  this  circuit  is 
that  once  the  operator  has  tuned  the  receiver  to  the 
station  with  which  he  desires  to  communicate,  the 
transmitter  is  also  sharply  tuned  on  approxi- 
mately the' same  wave. 

If  the  reader  will  follow  the  wiring  diagram 


MR.  PROCTER  S  ONE-TUBE  TRANSMITTER-RECEIVER 
Showing  the  third  key  contact,  with  its  binding  post  at  the  left  end  of  the  key  base  board.    The  left-hand  dial  controls  the 
43-plate  condenser.    The  other  large  dial  controls  the  secondary  of  the  variocoupler,  and  the  filament  rheostat  is  mounted 

in  the  centre  of  the  panel  below  the  milliameter 


30 


Radio  Broadcast 


THIS  IS  THE  CIRCUIT 
Which  is  used  in  Mr.  Procter's  set.    A,  is  the  primary  of  the  variocoupler  made  with 
a  special  winding,  B;  C,  tickler  coil;  D,  key  contact  used  for  transmitting;  E,  con- 
verted ordinary  telegraph  key;  F,  key  contact  for  closing  the  receiving  circuit;  G, 
B  battery  for  transmitting;  H,  B>  battery  for  receiving 


tubes.  This  divides  the 
stator  into  two  sections,  the 
larger  of  which  is  used  as 
the  antenna  tuning  induct- 
ance, while  the  smaller  is 
connected  between  one  ter- 
minal of  the  rotor  and  the 
auxiliary  source  of  plate 
potential  used  for  transmis- 
sion. This  is  used  in  series 
with  the  rotor  or  the  tickler 
coil  in  the  transmitting  cir- 
cuit, and  its  close  inductive 
relation  to  the  tuning  in- 
ductance insures  a  state  of 
oscillation  when  the  tele- 
graph key  is  depressed.  For 
the  benefit  of  those  who 
may  prefer  to  make  their 
own  variocoupler,  it  is  ad- 
vised that  No.  20  B.  &  S.  or 
a  larger  wire  be  used  for  the 
stator  winding  if  good  re- 
sults are  to  be  obtained. 

In  considering  the  grid 
condenser  and  grid  leak,  it  is 


closely  while  reading  the  description  of  the 
circuit,  he  should  have  no  trouble  in  under- 
standing the  working  principle  of  the  system 
and  afterward  constructing  the  set  itself. 

The  receiver  is  of  the  well  known  single- 
circuit  type,  and  gives  the  necessary  sharpness 
of  tuning  with  a  minimum  of  adjustments. 
A  variable  condenser  of  .001  mfd.  capacity  is 
placed  in  series  with  an  inductance  and  the 
antenna,  and  due  to  its  large  range  of  capacity 
it  provides  a  wavelength  variation  of  between 
1 75  and  400  meters,  with  an  antenna  of  average 
size.  The  experiment  of  placing  a  vernier  in 
parallel  across  the  plates  of  this  condenser  was 
tried  to  determine  the  advisability  of  leaving 
it  permanently  in  the  circuit,  but  while  the 
vernier  increased  the  sharpness  of  tuning  to 
some  extent,  it  was  not  considered  necessary 
to  make  it  a  fixture.  The  most  satisfactory 
inductance  unit  that  can  be  used  in  this  circuit 
is  a  vario-coupler  similar  to  the  Baldwin  type, 
as  this  instrument  is  particularly  adapted  to  the 
needs  of  the  set.  It  is  necessary  to  make  a 
slight  change  in  the  stator  winding,  to  give  a 
special  plate  inductance  required  in  the  trans- 
mitting circuit.  At  the  tenth  turn  from  the 
bottom  cut  the  stator  winding  and  remove  two 
turns,  fastening  the  ends  in  holes  drilled  in  the 


advised  that  a  mica  con- 
denser of  .00025  mfd.  capacity  be  employed. 
The  amateur  may  prefer  to  make  this  condenser 
variable  and  in  some  instances  a  variable 
capacity  may  be  of  some  aid  if  the  builder  is 
experimenting  with  different  makes  of  tubes. 
The  grid  leak  should  be  of  one  megohm  re- 
sistance at  the  most,  since  the  impulses  received 
are  relatively  weak,  while  the  transmitted 
impulses,  being  generated  locally,  are  rela- 
tively high. 

The  problem  of  selecting  the  right  vacuum 
tube  for  this  circuit  is  one  that  brings  up  many 
points  for  discussion,  since  the  tube  to  be  used 
must  be  one  that  will  cover  a  wide  range  of 
work.  It  must  not  only  give  good  service  as  a 
detector  but  must  also  be  capable  of  taking  a 
fairly  high  plate  potential  to  give  a  strong  out- 
put for  transmission.  For  the  set  described, 
the  Western  Electric  tube  or  V.T.  1  was  se- 
lected, since  its  filament  adjustment  is  not 
critical  and  its  insulation  permits  the  use  of 
plate  potentials  up  to  200  volts.  Much  valu- 
able knowledge  pertaining  to  the  functioning 
of  various  tubes  can  be  acquired  through  trying 
them  out  in  this  circuit. 

Next  comes  the  problem  of  choosing  the 
source  of  plate  potential.  B  batteries  have  their 
advantages,  giving  a  constant  source  of  cur- 


Transmitting  and  Receiving  with  the  Same  One-Tube  Set 


3i 


rent  without  the  variations  in  potential  com- 
mon in  other  forms  of  plate  current  supply. 
Moreover,  since  no  excessive  voltage  is  re- 
quired for  this  circuit,  a  few  45-volt  B  bat- 
teries are  all  that  are  necessary.  They  are  to 
be  found  in  any  receiving  station  and  can 
be  purchased  at  a  comparatively  low  cost. 
For  the  amateur  who  is  making  his  initial 
attempt  at  transmission,  this  method  should 
have  a  great  appeal. 

Another  method — the  use  of  a  small  dyna- 
motor  or  motor  generator — will  be  found  satis- 
factory by  those  who  already  have  one  in  their 
station,  if  it  does  not  give  too  high  an  output  for 
the  tube  used.  It  must  be  remembered  that  in 
this  circuit  the  plate  current  for  reception  and 
the  plate  current  for  transmission  will  be  in 
series  when  the  key  is  depressed,  and  the  plate 
of  the  tube  will  receive  the  sum  of  both  po- 
tentials. Therefore,  care  should  be  taken  not 
to  overlook  the  fact  that  an  additional  22^  or 
45  volts  will  be  added  to  the  voltage  of  the 
motor  generator  or  other  source  of  plate  cur- 


rent being  used.  In  purchasing  the  motor- 
generator  or  dynamotor,  it  is  strongly  advised 
that  one  of  standard  and  reputable  make  be 
selected,  since  a  cheap  one  is  likely  to  be  a 
constant  source  of  annoyance  and  disappoint- 
ment. It  should  have  a  large  number  of 
commutator  segments  for  otherwise  a  most 
unpleasant  generator  hum  will  be  heard  in 
the  receiving  station.  A  dynamotor  which 
supplies  both  filament  and  plate  current  will 
not  possess  the  usual  advantages  in  the  case 
at  hand,  since  it  would  necessitate  the  running 
of  the  machine  to  keep  the  tube  lighted  for 
receiving.  The  possibility  of  using  house  light- 
ing current  will  have  to  be  dwelt  upon  in  a  more 
lengthy  manner  than  the  two  former  methods. 

First,  110  D.  C.  may  be  directly  connected 
to  the  set.  This  system  gives  exactly  the 
same  results  as  those  obtained  by  the  use  of 
B  batteries,  except  that  the  potential  often 
varies,  dropping  below  1  10  volts  and  rising 
again,  if  some  excessive  load  has  been  placed 
on  the  house  lighting  circuit.    This  drop  will 


THERE   IS  NOTHING   VERY   COMPLICATED   ABOUT  THE  SET 
The  tube  in  the  picture,  a  Western  Electric  VT-i,  has  been  found  very  satisfactory  for  the  double  function  of  trans- 
mitting and  receiving;  but  other  "hard"  bulbs  may  be  employed,  especially  where  short  distances  are  to  be  covered 


32 


Radio  Broadcast 


naturally  have  an  effect  on  the  transmission 
in  progress  if  the  signals  at  the  receiving  station 
are  weak,  for  a  troublesome  fading  will  be 
noted.  If  the  current  is  sure  to  be  constant 
this  system  can  be  recommended  and  good  C. 
W.  transmission  will  take  place. 

Where  1 10  A.  C.  is  available,  it  may  be  used 
in  several  different  ways. 

The  first  of  these  is  direct  connection  from 
the  line  to  the  set.  The  advantage  of  this 
system  is  that  the 
quality  of  the  signal 
transmitted  makes  re- 
ception possible  over 
short  distances  with  a 
crystal  detector  or 
some  other  non-oscil- 
latory receiver,  since 
the  transmitted  wave 
will  be  broken  up  by 
the  set  ceasingto  oscil- 
late during  one  alter- 
nation. The  disad- 
vantage of  this  system 
is  that  if  sixty-cycle 
A.  C.  current  is  used, 
the  transmitted  note 
would  be  low  and  un- 
pleasant to  the  lis- 
tener. 

If  desired,  the  alter- 
nating current  may  be  connected  through  a 
transformer  to  increase  the  voltage  applied  to 
the  plate.  This  would  still  give  an  interrupted 
wave  of  very  low  tone,  although  the  higher 
plate  potential  would  increase  the  radiation. 

The  alternating  current  can  also  be  rectified. 
One  drawback  of  this  system  is  the  expense 
involved,  but  by  use  of  a  rectifying  device  the 
frequency  of  the  current  is  doubled,  giving  a 
120-cycle  note  at  the  receiving  end.  This  note 
is  much  more  pleasant  to  listen  to,  and  allows 
the  operator  to  use  more  speed  in  transmission, 
since  the  note  is  clear  and  the  dots  and  dashes 
are  sharply  defined. 

The  use  to  which  the  transmitter  is  to  be  put 
will  determine  whether  a  filter  should  be  em- 
ployed. A  filter  may  consist  of  a  choke  coil, 
large  capacity  condenser  or  a  combination  of 
both.  The  filter  serves  to  smooth  out  the 
ripple  in  the  120-cycle  current,  permitting 
transmission  on  a  continuous  wave  instead 
of  a  damped  wave.  The  ingenious  experi- 
menter should  be  able,  when  using  A.  C. 
current,  a  rectifier  and  a  filter,  to  put  in 


How  to  Get  Your  Transmitting 
Licenses 

If  you  wish  to  transmit,  you  must  have  two 
licenses,  one  certifying  you  as  an  operator,  the 
other  for  your  station.  You  must  be  able  to 
receive  at  least  ten  words  a  minute  (five  letters 
or  characters  to  the  word),  and  must  comply 
with  certain  other  requirements  explained  in 
the  Government  pamphlet:  "Radio  Com- 
munication Laws  of  the  United  States."  It  is 
advisable  to  obtain  this  pamphlet,  as  it  gives 
a  list  of  places  where  examinations  are  held 
and  other  information  either  necessary  or 
helpful  to  the  prospective  operator.  It  may 
be  had  from  the  Superintenent  of  Documents, 
Government  Printing  Office,  Washington, 
D.  C.    Price,  15  cents  a  copy. 


two  double-pole-double-throw  knife  switches 
around  his  filtering  system,  permitting  the  use 
of  either  straight  or  modulated  C.  W.  (con- 
tinuous-wave) transmission  at  will.  The  use  of 
either  of  these  forms  is  a  matter  of  preference, 
or  will  depend  on  the  character  of  the  work  to 
be  done.  For  the  amateur  who  desires  to  use 
his  set  for  field  work,  it  will  be  found  that  B 
batteries  are  the  most  convenient  source  of 
plate  current.    For  use  in  a  permanent  station, 

several  makes  of  stor- 
age B  batteries  can  be 
obtained  and  if  the 
station  has  a  battery 
charger  included  in  its 
equipment  they  w''.l 
be  found  satisfactory, 
although  for  field  work 
the  dry  battery  excels. 
After  reviewing  the 
different  methods  of 
obtaining  plate  cur- 
rent that  have  just 
been  outlined,  it  is  up 
to  the  builder  of  the 
set  to  choose  the 
method  which  he  con- 
siders the  best  adapted 
to  his  needs. 

As  mentioned  above, 
the  key  must  operate 
in  two  circuits,  the  receiving  and  the  transmit- 
ting. By  using  one  of  the  key  contacts  in  both 
circuits,  it  is  necessary  to  add  only  one  more 
contact.  First,  the  key  should  be  mounted  on  a 
bakelite  or  wood  base  and  a  hole  drilled  one- 
eighth  of  an  inch  directly  back  of  the  end  of  the 
the  key  arm  in  the  base.  A  machine  screw 
should  then  be  raised  up  through  this  hole  and 
held  in  place  by  a  nut.  Then  remove  the  nuts 
from  the  key  adjustment  in  the  rear  of  the  arm 
and  fasten  on  a  small  piece  of  strip  brass  which 
will  extend  out  in  the  rear  of  the  arm  and  make 
contact  with  the  machine  screw.  Then  re- 
place the  adjustment  nuts  to  hold  this  strip 
in  place,  and  the  key  conversion  is  complete. 

It  will  be  seen  that  when  the  key  is  in  the 
up  position  the  brass  strip  and  screw  make  the 
contact  in  the  receiving  circuit,  while  in  the 
down  position  the  key  contacts  close  the  trans- 
mitting circuit. 

It  was  not  the  author's  intention  to  tell 
exactly  how  to  build  this  set  part  by  part,  but 
rather  to  describe  the  circuit  and  explain  the 
use  of  each  instrument  involved.  Every  experi- 


Have  You  Heard  These  Stations  Yet? 


33 


menter  prefers  to  build  his  set  in  an  entirely  dif- 
ferent manner  from  any  one  else,  some  prefer- 
ring to  mount  the  instruments  on  a  board,  while 
others  are  partial  to  the  cabinet  arrangement. 
The  set  illustrated  was  built  by  the  author  and 
Walter  H.  Bullock,  to  whom  a  large  amount  of 
»  credit  must  be  given  for  his  aid  and  suggestions 
which  helped  the  author  prepare  this  article. 

So  far,  a  distance  of  eleven  miles  has  been 
covered  on  transmission  from  the  centre  of 


New  York  City  up  into  the  Bronx  under  very 
unfavorable  conditions,  and  signals  have  been 
received  from  a  broadcasting  station  in  Chi- 
cago (700  miles).  These  distances  exceed 
anything  expected  at  the  time  the  set  was 
designed.  It  is  hoped  that  many  of  you  will 
derive  pleasure  and  knowledge  from,  this 
circuit  and  may  do  the  kind  of  work  with  it  that 
will  make  you  feel  that  the  time  used  in  con- 
structing the  set  was  well  spent. 


Have  You  Heard  These  Stations  Yet? 

CKAC  in  Montreal,  WGR  in  Buffalo,  N.  Y.,  and  WGY  in 
Schenectady,  N.  Y.,  are  Broadcasting  Excellent  Musical  Programmes. 
Their  Wavelengths  are  430,  400  and  400  Meters,  Respectively 


UP  IN  Montreal,  Canada,  there  is 
a  French  newspaper  called  "  La 
Presse, "  which  has  installed  a 
broadcasting  station  that  is  unusual 
in  several  respects.  One  man,  Mr. 
N.  Carter,  performs  alone  the  various  duties 
of  announcer,  manager  and  operator.  This  he 
is  able  to  do  by  reason  of  the  special  type  of       CKAC  has  a  splendid  pipe  organ  of  its  own, 


J 


broadcasting  equipment  which,  although  the 
station  is  a  powerful  one,  is  simple  in  operation. 
No  motor  generators  are  used,  the  alternating 
current  supply  from  the  city  being  passed 
through  two  giant  rectifier  tubes  to  supply  the 
required  voltages. 


THE  ORGAN  AT  CKAC 
Station  of  the  French  newspaper,  La  Presse,  in  Montreal 


Supplying  Broadcasts  Like  Gas  or  Electricity 


35 


installed  in  the  studio.  The  illustration  on 
page  33  shows  an  organist  giving  a  recital 
to  an  audience  which  undoubtedly  contained 
as  many  Americans  as  Canadians.  The  lan- 
guage of  music  is,  of  course,  universal,  but  the 
announcements  at  CKAC  are  made  in  both 
French  and  English,  and  the  programmes,  also, 
are  given  sometimes  in  one  tongue,  sometimes 
in  the  other.  To  tune  in  this  Montreal  station, 
you  must  "go  up"  to  430  meters. 

The  Federal  Telephone  &  Telegraph  Com- 
pany has  a  station  in  Buffalo,  N.  Y.,  known  to  a 
large  radio  audience  as  WGR — possibly  you 
have  heard  of  it.  It  has  been  performing  a 
useful  service  in  transmitting  weather  and 
market  reports  as  well  as  all  manner  of  musical 
and  other  entertainment,  and  is  planning  to 
extend  its  scope  to  include  educational  courses 
of  various  kinds.  The  Broadcast  Division 
of  the  Federal  Company  expects  also  to  make 


WGR  a  public  forum  for  the  discussion  of 
matters  of  national  and  local  interest.  As  will 
be  seen  from  the  picture  on  the  opposite  page, 
an  elaborate  system  of  hangings  and  floor 
coverings  has  been  worked  out  which  isolates 
the  studio  from  all  sounds  but  those  desired 
for  broadcasting. 

A  third  station,  which  is  gaining  a  wide 
reputation  for  its  musical  programmes,  is  WGY, 
the  station  of  the  General  Electric  Company  at 
Schenectady,  N.  Y.  It  has  a  powerful  trans- 
mitting installation  and  has  been  heard  in 
every  state  in  the  Union  and  in  several  for- 
eign countries.  The  orchestra  which  is  shown 
in  the  picture  has  won  the  enthusiastic  praise 
of  listeners-in  from  far  and  near.  These  five 
players  also  supply  the  music  for  the  light 
operas,  such  as  Gilbert  and  Sullivan's  "  Pirates 
of  Penzance,"  broadcasted  from  WGY  from 
time  to  time. 


Supplying  Broadcasts  Like  Gas  or 

Electricity 

How  the  Municipal  Receiving  Station  in  Dundee,  Michigan,  Relays 
Radio  Entertainment  to  Private  Subscribers  Over  Land  Wires 

By  GRAYSON  L.  KIRK 


RECEIVING  conditions  in  Dundee, 
Michigan,  are  unusually  good.  You 
don't  need  any  aerial  or  ground. 
You  don't  even  have  to  have  a 
-radio  set.  In  fact,  you  can  hear 
programmes  from  stations  all  over  the  country 
on  nothing  but  $1.50  a  month  and  a  loud- 
speaker. 

Municipal  radio  is  the  answer;  and  Dundee, 
a  little  farming  village  of  less  than  a  thousand 
inhabitants,  proudly  boasts  the  first  working 
system  of  its  kind  in  the  United  States.  This 
village,  named  after  the  Scottish  community 
renowned  for  its  marmalade,  is  located  in  the 
rich  farming  district  of  Monroe  County,  Michi- 
gan, along  the  banks  of  the  River  Raisin. 
There  the  tired  farmer  goes  in  from  work,  closes 
a  switch,  and  without  any  tinkering  with 
instruments  may  listen  to  a  perfectly  tuned 
concert  from  almost  anywhere  in  the  country. 
In  the  pool  room  on  "Main  Street,"  an  eager 
crowd  gathers  on  summer  afternoons  to  listen 


to  Big  League  scores  or  Grand  Circuit  results. 
In  the  lobby  of  the  little  hotel  across  the  street 
the  college  student,  agenting  for  the  summer 
among  the  farmer  folk,  may  sit  of  an  evening 
and  listen  to  the  radio  concerts. 

All  this  is  now  possible  because  more  than 
a  year  ago,  Frank  W.  Gradolph,  President  of 
the  Farmers'  Telephone  Company  of  Dundee, 
had  a  vision — a  vision  whereby  his  company 
might  render  greater  service  to  the  town  and 
community.  He  saw  that  one  of  the  greatest 
handicaps  to  radio  receiving  was  the  even 
slight  technical  knowledge  and  expensive  in- 
struments necessary  for  satisfactory  opera- 
tion. And  he  saw  still  further  the  tremendous 
possibilities  that  would  be  opened  if  these 
difficulties  could  be  eliminated. 

The  project  at  first  seemed  foolhardy,  if  not 
actually  impossible.  Obviously  a  central  sta- 
tion and  receiving  apparatus  were  a  necessity. 
But  how  could  the  sound  be  distributed  from 
such  a  station  without  losing  any  of  its  tonal 


36 


Radio  Broadcast 


THE   RE-BROADCASTING   STATION   AT  DUNDEE,  MICHIGAN 

Here  is  where  the  entertainment  for  a  whole  community  is  tuned  in  every  evening.  It  is  transferred  to 
land  wires  running  to  the  homes  of  the  various  subscribers,  who  pay  $1.50  a  month  for  the  service 


quality?  What  sort  of  wire  would  be  required? 
Would  telephonic  interference  demand  special 
poles? 

These  were  a  few  of  the  problems  that  beset 
the  originator  of  the  project.  He  was  undaunt- 
ed, however,  and  after  a  stormy  session  the 
consent  of  the  board  of  directors  was  secured 
and  the  work  was  begun. 

First,  a  powerful  receiving  set  was  purchased 
and  installed  in  the  office  of  the  telephone 
company.  Batteries  of  a  special  design  and 
extra  strength  were  purchased.  Then  came 
the  problem  of  a  suitable  aerial.  The  company 
erected  a  tall  well-braced  mast  on  the  roof  of 
their  own  three-story  building  and  secured  per- 
mission from  the  owner  of  a  neighboring  build- 
ing to  erect  on  its  roof  a  similar  mast.  A 
customary  four-wire  antenna  was  stretched 
between  them  and  connections  were  made.  It 
gave  splendid  results  in  the  little  telephone 


office.  Could  the  sound  be  distributed  all  over 
town  satisfactorily? 

This  problem  of  distribution  proved  to  be 
the  greatest  obstacle  the  company  had  to  face. 
At  first  a  few  loud  speakers  were  installed  in 
various  homes  about  town  and  were  connected 
to  the  central  station  by  means  of  uninsulated 
telephone  wire  strung  along  on  the  telephone 
poles. 

The  result  was  discouraging.  The  sound 
seemed  to  have  sufficient  volume  but  the  tonal 
quality  was  ruined.  The  music  was  changed 
into  a  blaring  static-charged  discord.  The 
officials  decided  that  the  trouble  was  caused  by 
the  interference  of  the  telephone  currents  and 
they  set  about  to  remedy  the  difficulty.  They 
tore  down  the  transmission  wire  and  in  its  place 
substituted  a  medium  grade  of  light  insulated 
wire,  such  as  is  often  used  in  house  wiring. 

The  results  this  time  were  better,  but  by  no 


Supplying  Broadcasts  Like  Gas  or  Electricity 


means  satisfactory.  So,  profiting  by  their 
experience,  the  wires  were  once  again  torn 
down,  and  replaced  with  a  very  heavily 
insulated  wire.  More  than  six  months  had 
now  elapsed  since  their  first  experiments,  and 
the  directors  of  the  company  were  beginning 
to  grow  impatient.  Would  it  be  a  success 
this  time  or  were  they  again  destined  to  fail? 

Giving  orders  to  the  operator  to  open  the 
circuit  at  a  certain  time,  the  officials  hurried 
down  to  one  of  the  homes  that  had  a  Magna  vox 
installation.  They  waited  in  suspense;  and 
suddenly  there  burst  from  the  horn  the  sound  of 
a  voice  singing.  The  tone  was  full  and  clear. 
The  reproduction  was  almost  perfect.  The 
experiment  was  an  unqualified  success! 

News  of  the  success  of  the  venture  spread, 
and  within  a  few  days  the  office  was  besieged 
with  townspeople  clamoring  for  an  installa- 
tion. The  troubles  of  the  company,  though, 
were  not  yet  over,  for  difficulty  in  distribution 
arose  almost  immediately.  As  the  number  of 
phones  or  horns  was  increased  the  volume  of 
sound  steadily  decreased,  until  the  results  were 
as  unsatisfactory  as  before. 

Various  schemes  of  overcoming  the  trouble 
were  tried  and  finally  the  electricians  hit  upon 
the  idea  of  dividing  the  town  into  four  dis- 


37 

tribution  districts  and  effecting  a  quadruple 
distribution  from  these  four  main  conduits. 
As  a  further  aid,  more  powerful  batteries  were 
installed  in  the  central  station.  Once  again  the 
results  were  satisfactory. 

The  entire  mechanical  force  of  the  telephone 
company  was  placed  on  the  work  of  installing 
and  soon  practically  every  home  in  the  village 
was  able  to  enjoy,  without  any  technical  knowl- 
edge or  expensive  receiving  outfit,  radio  con- 
certs and  programmes  picked  up  from  many 
parts  of  the  United  States  by  the  powerful  cen- 
tral station. 

F.  W.  Gradolph,  the  man  who  was  credited 
earlier  in  this  story  with  the  original  idea  and 
subsequent  realization  of  the  project,  is  a  quiet 
electrician  and  business  man  of  early  middle 
age,  who  takes  a  naive  and  pardonable  pride  in 
being  able  to  provide  this  broadcast  service  at 
a  charge  of  one  dollar  and  a  half  a  month  to 
each  subscriber. 

It  is  the  opinion  of  everyone  who  has 
witnessed  the  successful  operation  of  the  Dun- 
dee experiment  that  this  community  really  "has 
something."  Who  will  say  how  many  Dundees, 
all  over  the  country,  will  be  adopting  this 
system  of  municipal  radio  within  the  next  few 
years? 


THE  MUSIC  FLOODS  THE  LOCAL  STORE 

One  drawback  to  this  system  of  re-broadcasting  is  that  if  one  subscriber  doesn't  like  the  selections  provided, 
he  cannot  turn  a  knob  and  bring  in  something  else.    It's  a  case  of  take  it  or  leave — the  switch  open 


The  "Neutrodyne"  Receiving  System 


Outlining  the  Hazeltine  Method  of  Securing  Radio  Fre- 
quency Amplification  Without  Regeneration  or  Reradiation 

By  KIMBALL  H.  STARK 

Chief  Engineer,  F.  A.  D.  Andrea,  Inc. 


R'.DIO  enthusiasts  speak  freely  of 
audions,  pliotrons,  dynatrons,  sup- 
er-regeneration and  heterodyne;  but 
now  comes  a  new  word— "neu- 
trodyne." 

Neutrodyne  is  the  coined  name  for  a  revolu- 
tionary radio  receiver  circuit  that  seemingly 
achieves  the  impossible.  It  neutralizes  the 
capacity  coupling  of  the  circuits  and  allows  very 
efficient  radio-frequency  amplification  even  on 
short  wavelengths.  In  effect,  the  usual  re- 
generation of  the  circuit  is  eliminated  by  this 
method  of  neutralizing  the  coupling  capac- 
ities. 

On  the  evening  of  March  2nd,  1923,  Professor 
L.  A.  Hazeltine,  Professor  of  Electrical  Engi- 
neering at  Stevens  Institute  of  Technology,  Ho- 
boken,  N.  J.,  delivered  a  lecture  before  a 
meeting  of  the  Radio  Club  of  America,  telling 
in  detail  of  his  work  which,  extending  over  a 
number  of  years,  has  resulted  in  the  develop- 
ment of  the  neutrodyne  circuit.  The  applica- 
tion of  this  circuit  to  the  problem  of  radio- 
frequency  amplification  is  only  one  of  the  uses 
of  the  neutrodyne  principle  as  developed  by 
Professor  Hazeltine. 

Briefly  reviewing  the  methods  of  producing 


IN  THIS  NEUTRODYNE  RECEIVER 
All  the  tuning  is  done  with  the  three  dials.    In  a  test  made 
by  Radio  Broadcast,  broadcasting  stations  over  a  thou- 
sand miles  distant  were  heard  on  a  loud  speaker  ar  night 


amplification  in  radio  receiver  circuits,  we 
find  that  radio-frequency  amplification  can  be 
obtained  by  using  three  possible  methods  of 
coupling  one  circuit  to  another,  namely,  re- 
sistance coupling,  impedance  coupling  and 
transformer  coupling.  Resistance  coupling  is 
possibly  desirable  when  wavelengths  above 
1,000  meters  can  be  used,  but  the  amplification 
per  stage  is  not  great  and  the  tuning  is  broad. 
Impedince-coupled  amplifiers  when  tuned  are 
much  more  efficient  and  good  results  have  been 
obtained  from  their  use.  If  two  or  more  stages 
of  tuned  impedance  amplification  are  employed, 
however,  the  sharpness  of  tuning  means  very 
difficult  adjustments  and  as  a  result  cascade 
amplifiers  of  this  type  are  not  in  general  use. 
On  the  other  hand,  transformer  coupling  of 
amplifier  circuits,  because  it  has  been  standard 
practice  with  audio  frequency  circuits,  has 
always  found  favor  with  both  professional  radio 
engineers  and  amateur  experimenters  as  the 
ideal  method  of  obtaining  efficient  radio-fre- 
quency amplification. 

To  date,  two  general  devices  for  transformer- 
coupled  radio-frequency  amplifying  circuits 
have  been  used;  those  employing  air-core 
transformers  and  those  having  iron-core  trans- 
formers. Circuits  using  air- 
cored  transformers  are  ex- 
tremely sharp  in  their  tuning 
and  the  wavelength  range  of 
the  transformers  is  necessarily 
limited.  In  cascade  ampli- 
fiers of  this  type  a  multiplicity 
of  controls  is  thus  necessary, 
and  very  accurate  tuning  is: 
required  for  each  stage  to  get 
good  results  on  the  various 
wavelengths.  For  some  time 
iron-cored  transformers  for 
radio  frequency  work  were 
thought  to  be  impracticable, 
due  to  the  enormous  eddy- 
current  and  hysteresis  losses 
developed  in  the  cores  at 


The  "Neutrodyne"  Receiving  System 


39 


these  high  frequencies.  Later  work  with  iron- 
cored  transformers  showed  that  by  using  cores 
made  of  special,  very  thin  laminations  and  tak- 
ing great  care  in  the  design  and  assembly  of  the 
transformer,  quite  satisfactory  amplification 
could  be  obtained. 

Special  means  were  devised  to  broaden  the 
wavelength  band,  but  even  as  with  air-cored 
transformers,  it  was  impossible  to  utilize  wind- 
ings with  a  step-up  ratio.  Thus  several  stages 
were  needed  to  obtain  long  distance  signals. 

As  nearly  every  experimenter  will  agree,  it 
is  exceedingly  difficult  to  hook  up,  even  in 
the  laboratory,  either  of  these  types  of  radio- 
frequency  amplifier  circuits  and  not  get  oneself 
into  all  sorts  of  trouble.  At  high  frequencies 
the  losses  in  the  insulating  materials  used,  the 
necessity  for  making  all  soldered  connections 
of  low  resistance,  and  the  very  great  drawback 
of  the  impossibility  of  eliminating  the  capacity 
coupling  between  the  circuit  and  its  various 
parts,  make  the  problem  seem  impossible  of 
solution.  The  matter  of  capacity  coupling  is 
obviously  the  most  important.  The  capacity 
of  the  output  circuit  to  the  input  circuit  between 
the  wiring  of  the  set  provides  a  path  for  a  feed 
back  of  energy  with  the  result  that  the  apparatus 
oscillates.  In  broadcast  reception  using  this 
sort  of  equipment  the  incoming  signals  are 
likely  to  be  distorted,  the  overtones  and  under- 
tones being  eliminated,  and  the  tuning  ac- 
companied by  whistles  as  each  carrier  wave  is 
crossed.  In  addition  to  the  capacity  coupling 
between  the  circuits  the  inductive  coupling  of 
transformers,  inductances,  etc.,  is  also  likely  to 
bring  this  reaction  about. 

THE  THEORY  OF  THE  NEUTRODYNE 

PROFESSOR  Hazeltine  in  his  lecture  pointed 
out  methods  of  overcoming,  through  neutral- 
ization, these  various  capacities  between  com- 
ponent parts  of  receiver  and  amplifier  circuits. 
Theoretically  his  method  may  be  explained  as 
shown  graphically  in  Fig.  i.  We  have  two  cir- 
cuits, A  and  B,  coupled  to  each  other  by  a  metal- 
lic connection  C  and,  in  addition,  by  the  coupling 
capacity  D.  A  magnetomotive  force  is  set  up  in 
circuit  B  because  of  energy  being  transferred 
by  the  capacity  coupling,  a  voltage  and  current 
transfer  taking  place.  This  condition  in  many 
instances  is  undesirable  and  decreases  the 
efficiency  of  the  receiver  or  amplifier  circuit. 

To  make  clear  his  method  of  neutralizing 
this  capacity  coupling  between  circuits,  Profes- 
sor Hazeltine  explains  by  the  drawing  the  use 


CAPACITY  COUPLIMSv 


POINT  OF  DISTURBING  POTENTIAL 


FIG.  1 

A  theoretical  presentation  of  Prof. 
Hazeltine's   neutralizing  scheme 


of  an  inductance  tapped  in  the  centre  as  shown. 
To  the  point  of  the  disturbing  potential  on  the 
circuit  B  one  end  of  this  inductance  is  connected 
and  the  other  end  is  connected  to  a  similar 
point  on  circuit  A  through  an  adjustable  neu- 
tralizing capacity.  The  centre  tap  of  this 
inductance  system  is  connected  to  the  low 
potential  point  of  the  circuit  B.  In  effect,  the 
path  of  the  voltage  and  current  is  as  shown 
by  the  arrows,  with  the  energy  caused  by  the 
parasitic  capacity  coupling  D  passing  down 
through  coil  E  in  one  direction  and  with  the 
current  and  voltage  in  the  opposite  direction 
through  branch  F,  going  into  the  inductance 
system  as  an  opposing  voltage,  thus  inductively 
neutralizing  the  coupling  capacity  effect  and 
causing  no  voltage  across  the  terminals  of 
circuit  B. 

As  applied  to  radio  circuits  the  drawing  of 
Fig.  2  shows  the  device  adapted  to  neutralizing 
the  grid-to-plate  capacity  of  vacuum  tubes.  In 
this  circuit  coils  E  and  F  are  placed  respective- 
ly in  the  grid  and  plate  circuits  while  the  centre 
tap  goes  to  the  common  filament  connection. 
The  grid-plate  capacity  is  shown  by  dotted 
lines  and  the  neutralizing  capacity  is  adjusted 
to  offset  the  grid-plate  capacity  coupling.  It  is 
possible  that  the  inductances  E  and  F  might 
be  replaced  by  the  inductances  of  other  units 
as  used  in  the  circuit,  as  for  instance  the  primary 
and  secondary  coils  of  an  air-core  radio  fre- 
quency transformer.  Professor  Hazeltine 
showed  that  the  character  of  these  transformers 
affects  the  size  of  the  balancing-out  neutralizing 
capacity  and  that  in  his  system  it  is  possible 
to  utilize  transformers  with  a  step-up  ratio  in 
the  order  of  one  to  four  and  thus  reduce  the 


40 


Radio  Broadcast 


■  GRID  PLATE  CAPACITY 


"B"  BATT. 

HUM 


be 


IMPEDANCE  WHICH  MAY 
BE  TELEPHONE  RECEIVER 


NEUTRALIZING  CAPACITY 


FIG.  2 

Applying  the  neutralizing  method 
to     a    vacuum     tube  circuit 

capacity  of  the  neutralizing  condenser  to  ap- 
proximately one  or  two  micro-microfarads. 

In  both  of  these  explanatory  drawings  the 
capacity  to  be  neutralized  out  or  eliminated 
has  been  represented  by  dotted  lines  as  being 
only  a  single  capacity.  In  practice  this  capaci- 
ty may  be  made  up  of  a  great  number  of  small 
capacities  whose  total  is  balanced  out  by 
the  neutralizing  capacity. 

Accompanying  illustrations  show  interior 
and  exterior  yiews  of  a  receiver  built  by  F. 
A.  D.  Andrea,  Inc.,  employing  the  Hazeltine 
principle  in  its  commercial  form.  It  will  be 
noted  that  but  four  controls  are  used,  three 
of  them  being  tuning  controls  and  the  other 
being  the  detector  tube  vernier  rheostat. 
Two  stages  of  tuned  radio-frequency  amplifica- 
tion, a  vacuum-tube  detector,  and  two  stages 
of  audio-frequency  transformer-coupled  ampli- 
fication is  obtained,  using  only  four  tubes. 
One  tube  does  double  duty  as  both  audio- 
and  radio-frequency  amplifier. 

In  the  interior  view  the  amplifying  trans- 
formers are  shown  in  the  foreground.  Three 
variable  air  condensers  are  mounted  directly 
behind  them  and  the  transformers  assume  an 
angle  with  respect  to  each  other  such  that  no 
electro-magnetic  coupling  exists  between  them. 
The  variable  condensers  shown  in  the  wiring 
diagram  in  Fig.  4  are  placed  in  parallel  with 
the  radio-frequency  transformer  secondaries, 
forming  closed  oscillatory  circuits,  so  that  dial 
settings  for  these  condensers  remain  practi- 
cally alike  for  any  given  wavelength.  The 
settings  of  dial  one,  which  is  across  the  sec- 
ondary of  the  transformer  whose  primary  is  in 
the  open  oscillatory  antenna  circuit,  will  vary 


in  setting  with  various  sizes  of  antennas  used. 
With  the  average  antenna,  however,  it  should 
not  vary  more  than  io°  to  120  above  or  below 
the  settings  of  dials  two  and  three  counting 
from  the  left. 

The  important  neutralizing  condensers  are 
pictured  just  above  and  between  the  variable 
condensers  and  transformer  units.  It  is  rather 
difficult  to  imagine  a  variable  condenser  having 
so  small  a  capacity  as  1  micro-microfarad  and 
with  the  added  advantage  of  having  no  con- 
nection to  its  moveable  element.  Such  a  con- 
denser can  be  readily  constructed.  As  shown 
in  the  drawing  in  Fig.  3  it  consists  of  an  insu- 
lated sleeve  in  which  are  inserted  two  pieces  of 
wire  with  about  f  inch  space  between  them  at 
the  center.  A  metal  tube  is  adjusted  length- 
wise outside  of  the  insulating  sleeve  over 
the  ends  of  the  two  wires.  The  resulting  ca- 
pacity is  the  series  capacity  of  the  metal 
tube  to  both  wires.  After  this  capacity  is 
adjusted  during  the  testing  of  the  receiver  it  is 
sealed,  being  adjusted  carefully  for  the  particu- 
lar types  of  vacuum  tubes  used.  The  adjust- 
ment of  these  neutralizing  capacities  is  made 
experimentally  by  tuning  in  a  strong  signal, 
then  turning  out  the  filament  of  the  tube'  whose 
capacity  is  to  be  matched  but  leaving  the  tube 
in  its  socket.  If  the  neutralizing  capacity 
is  not  correct  the  circuits  on  each  side  of  the 
tube  will  have  capacity  coupling  which  will 
transmit  the  signals  into  the  receivers.  The 
neutralizing  capacity  is  then  adjusted  until 
the  signal  disappears,  then  sealed  in  place. 
Such  a  method  illustrates  that  the  neutrodyne 
circuit  operates  to  eliminate  the  capacity  coup- 


INSULATING 
SLEEVE  - 


1  ;  


NEUTRALIZING  >rl 
SLEEVE   


WIRE 


I" 


SPACE 


Cz 


-H- 


FIG.  3 

The  arrangement  shown  in  A  forms  a  condenser 
shown  in  B.  The  resultant  capacity  is  the  series 
capacity  of  the  two  rods  to  the  neutralizing  sleeve 


<D 


6 


1  £" 


FIG.  4 


1 


THE  NEUTRODYNE  SYSTEM  APPLIED  TO  A  RECEIVER  FOR  GENERAL  USE 
In  which  there  are  three  air-core  transformers  with  tuned  secondaries.    The  left  hand  one  functions  in 
the  antenna  circuit  while  the  other  two  are  used  for  the  tuned  R.  F.  inter-stage  coupling  transformers 


ling  and  is  not  just  a  method  for  opposing  the 
effects  of  regeneration,  because  the  adjustment 
is  made  while  the  filament  is  cold  and  there- 
fore under  conditions  when  the  tube  could  not 
regenerate. 

With  one  of  these  receivers  utilizing  the 
neutrodyne  circuit  and  only  four  vacuum 
tubes,  three  of  the  stations  copied  from  New 
York  City  are  noted  below,  together  with  the 
dial  settings.  In  this  work  an  indoor  antenna 
was  used  consisting  of  about  50  ft.  of  annuncia- 
tor wire  running  along  the  picture  molding. 

A  glance  at  the  dial  setting  indicates  the  sharp- 
ness with  which  tuning  may  be  accomplished. 

Dial  1     Dial  2 

KYW     Chicago,  111.  ^  66 

WOO     Philadelphia,  Pa. 
WGM    Atlanta,  Ga. 


35 
35-5 
46 


67 
74 


Dial  3 
66.5 
65 

7'-5 


Another  advantage  of  the  neutrodyne  capa- 
city neutralizing  circuit  is 
the  fact  that  it  can  be  used 
with  circuits  employing  re- 
generation if  desired.  This 
means  that  amateur  C.  W. 
reception  can  be  carried  out 
successfully  over  very  long 
distances;  in  fact,  several 
tests  made  in  New  York  City 
by  amateurs  not  particularly 
familiar  with  the  circuit 
have  resulted  in  reception 
from  every  district  in  the 
country,  stations  from  the 


West  Coast  coming  in  clearly  and  with  good 
volume. . 

From  a  non-interference  point  of  view  the 
neutrodyne  circuit  possesses  great  advantages 
because  it  does  not  re-radiate  even  when  used  in 
connection  with  regenerative  circuits,  because 
it  does  not  allow  energy  to  be  fed  back  into 
the  antenna — in  other  words,  oscillation,  if  it 
occurs  at  all,  is  confined  to  the  detector  circuit. 

The  selectivity  of  the  receiver  is  great  and 
yet  because  no  regeneration  occurs  it  is  pos- 
sible for  even  the  novice  broadcast  listener  to 
adjust  the  three  dials  quickly  and  receive 
concerts  with  great  clarity.  Dial  settings  for 
various  stations  read  like  football  signals,  and 
to  be  able  to  have  the  women  folks  turn  the 
dials  to  prearranged  settings,  throw  in  the 
filament  switch  and  pull  in  broadcasting 
stations  1 500  miles  away,  is  a  feat  that  even 
some  of  the  older  radio  "night-hawks"  envy. 


THE  INTERIOR  OF  THE  RECEIVER 

Is  well  planned.  Note  the  angle  at  which  the  transformers  are  mounted 
to  cut  out  electro-magnetic  coupling.  The  brass  sleeves  which  form 
the  neutralizing  condensers  may  be  seen  between  the  transformers 


An  SOS  in  the  Jungle  of  Indo-China 

By  LELAND  L.  SMITH 

How  a  Distress  Call,  Flashed  from  a  Remote  French  Outpost,  Brought 
Airplane  Assistance  at  the  Critical  Moment  in  an  Uprising  of  Moi  Natives 


THE  most  easterly  town  on  the  coast 
of  French  Indo-China,  Qui  Nhon,  lies 
at  the  door  of  the  wildest  hunting 
country  that  I  have  been  able  to  find 
anything  about.  When  I  arrived 
there,  looking  for  a  bit  of  hunting  and  liter- 
ally "a  place  in  the  sun"  as  a  relief  after 
campaigning  in  Siberia,  only  ten  French  gov- 
ernment officials  inhabited  the  place,  but 
they  immediately  opened  their  arms  to  a 
former  American  army  officer.  While  talk- 
ing to  one  of  them,  1  was  suddenly  asked 

whether  I  happened  to   

come  from  Pittsburgh. 
Being  a  good  Yankee, 
I  replied  with  a  ques- 
tion, asking  why  of 
all  American  cities  he 
had  inquired  about 
Pittsburgh. 

"Well,"  the  official 
replied,  "  1  am  one  of 
the  only  two  living 
persons  bearing  the 
name  of  Duquesne, 
the  founder  of  Pitts- 
burgh; and  it  is  my 
greatest  wish  to  visit 
that  city." 

There  was  some- 
thing interesting  about  this  man  who  was 
keeping  up  the  pioneering  history  of  his 
family.  We  became  good  friends  and  he 
gladly  gave  me  all  the  information  that  1 
needed.  We  had  still  another  thing  in  com- 
mon: Mr.  Duquesne  turned  out  to  be  in  charge 
of  the  government  radio  station  at  that  point 
and  1  had,  shortly  before  leaving  Siberia,  been 
transferred  to  the  wireless  branch  of  the  Signal 
Corps.  1  was  naturally  delighted  when  I  was 
invited  to  visit  his  plant,  which  I  found  to  be 
very  modern  and  large  enough  to  protect  the 
shipping  of  perhaps  the  worst  bit  of  typhoon 
coast  in  the  world. 

His  stories  about  the  China  Sea  were  thrill- 
ing, but  what  whetted  my  imagination  most 


"After  having  spent  a  rather  frigid  time 
in  Siberia  fighting  for  democracy,"  writes  Mr. 
Smith,  "  I  decided  to  look  for  a  place  where  I 
could  thaw  out.  I  hunted  up  a  map  of  the 
world,  and  putting  my  finger  on  the  equator", 
started  searching  for  the  most  out-of-the-way, 
hot  place  on  the  globe.  My  eyes  fell  on  Indo- 
China,  and  then  and  there  I  decided  that  Indo- 
China  was  the  place  for  me."  After  reading 
the  following  account  of  his  experiences  there, 
we  are  inclined  to  think  it  isn't  the  place  for 
any  white  man.  But  the  French  Colonials 
make  existence  in  the  jungle  more  endurable 
and  less  hazardous  by  the  use  of  radio  at  their 
outposts. — The  Editor. 


was  his  account  of  how  a  tiny  French  post,  lost 
in  the  wilds  of  the  Annam  mountains,  had  been 
saved  from  annihilation  at  the  hands  of  the  Moi 
natives  by  the  use  of  radio.  It  seemed  that 
the  natives  of  the  mountains  had  yet  to  be 
brought  under  the  domination  of  the  French. 
Military  posts  were  gradually  being  established 
in  the  interior,  but  slowly,  as  most  of  the  Colo- 
nial troops  were  still  in  France  and  the  native 
Annamite  troops  were  too  much  of  an  unknown 
quantity  to  undertake  the  subjugation  of  the 
Mois.    Directly  East  of  Qui  Nhon,  200  kilome- 

  ters  away,  was  a  post 

called  KonTum  which 
had  no  means  of  com- 
municating with  the 
outside  world  except 
radio.  Telephone  and 
telegraph  wires  had 
been  strung  several 
times,  but  wild  ele- 
phants had  destroyed 
them  as  fast  as  they 
were  laid.  Therefore, 
a  field  wireless  had 
been  installed  at  the 
post.  An  automobile 
road  was  in  the  course 
of  construction  but 
only  half  was  com- 
pleted, and  the  rest  of  the  distance  to  the  post 
had  to  be  made  over  a  jungle  trail — impassable 
after  a  tropical  rain — by  ox-carts. 

A  year  before,  the  natives,  who  are  religious 
fanatics,  had  become  excited  over  some  fancied 
wrong  to  their  faith  and  had  attacked  the  post. 
Many  were  killed  by  machine  gun  fire  but  the 
Mois,  in  their  religious  wars,  seek  death,  be- 
lieving that  the  supreme  sacrifice  in  battle  will 
render  them  salvation.  The  supply  of  am- 
munition had  run  low  and  the  post  was  soon 
reduced  to  a  state  of  starvation.  There  had 
been  a  succession  of  electrical  storms  that  had 
temporarily  put  the  field  radio  set  out  of  com- 
mission, and  it  was  only  by  hard  work  and  good 
luck  that  the  news  of  the  outbreak  was  received 


An  SOS  in  the  Jungle  of  Indo-China 


43 


by  the  Qui  Nhon  station. 
It  was  impossible  for  relief 
to  arrive  immediately  and 
it  was  doubtful  if  the  hand- 
ful of  men  that  Qui  Nhon 
could  spare  would  be  enough 
to  cope  with  the  situation. 
The  lieutenant  in  charge  of 
the  besieged  fort  had  the 
idea  of  calling  by  radio  for 
two  aeroplanes  that  were 
stationed  at  Qui  Nhon,  as 
the  Mois  had  always  taken 
to  flight  upon  the  one  or 
two  occasions  that  planes 
had  cruised  over  the  coun- 
try. The  weather  being 
favorable,  the  planes  had 
set  out  and,  upon  arriving 
over  the  fort,  dropped  a  few 
bombs  and  opened  up  at 
close  range  with  machine 
guns.  As  if  by  magic,  the 
natives  took  to  their  heels 
and  had  not  bothered  the 
post  since.  The  French  had 
since  increased  the  number 
of  planes  on  the  Annam 
coast  in  case  of  a  recurrence 
of  the  outbreak.  But  the 
machines  were  never  al- 
lowed to  fly  inland  often 
enough  for  the  Mois  to  get 
accustomed  to  them. 

1  was  very  much  inter- 
ested in  the  story  and  in- 
quired whether  it  would  be 
possible  for  me  to  visit  the 
post,  and  whether  I  could 
obtain  any  big  game  such 
as  tiger  and  elephant  at  the  same  time.  I 
was  told  that  Qui  Nhon  communicated  with 
the  post  twice  a  day  and  if  I  would  be  at 
the  station  on  the  following  morning  at 
seven  I  could  ask  as  many  questions  as  I  de- 
sired. It  was  finally  arranged  that  I  should 
go  to  the  camp  and  participate  in  a  hunt  for  a 
man-eating  tiger  that  had  been  ravaging  the 
neighboring  Moi  tribe.  So,  on  the  following 
day,  I  set  out  for  the  jungle  post,  loaded  with 
equipment  and  supplies  that  the  French  officials 
had  given  me  or  recommended. 

The  first  100  kilometers  were  quickly  covered 
by  automobile  over  a  road  that  led  directly 
into    the    mountains    and    through  dense 


THIS  MOI  CHIEF  THREW  HIS  VICTIMS  TO  THE  ELEPHANTS 
Lieutenant  Gobert  would  have  suffered  this  death,  had  not  the  author  been  success- 
ful in  summoning  French  army  planes  by  radio.    The  long  double  piece  of  wire  in  the 
chief's  hair  was  originally  part  of  some  European  cooking  utensil.    Note  the  large 
wheel  on  the  native  cart.    Wheels  of  jungle  carts  are  never  greased  in  Indo-China 
as  the  ear-splitting  shrieks  they  make  serve  to  keep  tigers  and  leopards  at  a  safe 

distance 


jungles.  Then  I  was  bundled  into  an  ox-cart 
and  plunged  into  the  dark  country  away  from 
the  white  man's  land. 

A  man  who  has  never  seen  a"  real  jungle 
cannot  even  guess  at  its  denseness,  or  its 
vivid  color.  For  hours  at  a  time,  it  seemed, 
the  bamboo  "brousse,"  as  the  French  call  it, 
hid  the  sight  of  the  sky,  its  long,  curving  stalks 
closing  like  a  net  over  the  thin  trail.  Flowering 
vines  hung  from  the  branches  like  Japanese 
filmy  curtains.  The  solemn  oxen,  that  carried 
me  jerkily  over  the  rough  road,  ruthlessly  tore 
down  the  colored  strands  and  munched  the 
most  exquisite  orchids.  Monkeys  followed 
overhead,  chattering  and  making  a  terrific 


44 


Radio  Broadcast 


racket.  Gay-plumed  parrots,  noble  peacocks, 
deer,  and  wild  boar  were  encountered  contin- 
ually. As  the  heat  was  terrific,  the  oxen  were 
rested  at  every  creek  and  1  was  able  to  peer 
into  the  jungle  at  close  range.  The  length  of 
my  nose  was  about  as  far  as  I  could  get,  and  I 
thought  to  myself  that  Siberia  and  the  Bolshe- 
viki  had  been  less  dangerous  than  this  new 
kind  of  No  Man's  Land.  My  white  escort  had 
left  me,  and  four  half-naked  Annamites  and 
one  child  had  taken  possession  of  me.  Their 
apparent  unconcern,  however,  reassured  me. 

The  cart  that  was  carrying  me  to 
Kon  Turn  had  the  largest  wheels  I 
have  ever  seen  outside  of  a  power 
house,  and  when  they  revolved  they 
made  a  sound  like  the  singing  of  every 
canary  that  the  islands  of  that  name 
had  ever  been  guilty  of  exporting. 
An  investigation  elicited  the  fact  that 
wooden  hubs,  revolving  on  wooden 
axles,  were  sending  forth  the  air  splitting  shrieks 
that  went  echoing  away  into  the  jungle.  The 
driver,  who  spoke  an  extremely  Annamite- 
French,  advised  me  that  the  noise  was  made  on 
purpose  as  tigers  and  leopards  never  attacked 
a  squeaking  vehicle.  He  added  that  no  person 
would  ever  get  out  of  the  jungle  alive  in  a 
noiseless  cart.  From  then  on,  the  squeaks 
became  the  most  beautiful  music,  and  the 
louder  they  became  the  more  I  liked  it. 

We  arrived  at  an  open  space  shortly  before 
sunset  and  preparations  were  made  to  spend 
the  night.  I  had  always  dreamt  of  sleeping  in 
a  hammock  suspended  between  two  palm-trees 
and  it  was  with  a  thrill  of  delight  that  I  started 
to  hang  my  swinging  bed  between  two  royal 
palms  not  far  from  the  fire.  The  entire  An- 
namite  contingent  protested  violently.  I  was 
unable  to  understand  why,  but  resigned  myself 
to  my  fate  and  removed  my  stuff  to  the  covered 
cart.  After  an  exceedingly  Annamite  meal, 
which  I  could  not  eat  (having  seen  it  cooked),  I 
sat  down  under  the  palms  and  watched  the  light 
of  the  day  disappear  over  the  jungle,  or  rather  it 
seemed  that  the  sombre,  tangled  forest  arose 
and  blotted  out  the  light.  Never  will  I  forget 
the  intricate  laciness  of  the  bamboo  foliage; 
nor  the  majesty  of  the  scattered  royal  palms  as 
they  struggled  to  retain  the  light  a  little  longer 
than  their  less  tall  companions;  or  the  weird 
callsthatcame  fromthe  depthsof  the  jungle  and 
were  echoed  again  and  again  on  my  spinal  cord. 

A  sharp  pain  on  my  wrist  brought  me  to  with 
a  start.    I  naturally  grabbed  the  outraged  spot 


and  felt  hot  blood.  Another  pain  struck  me  in 
the  neck;  it  was  so  sharp  that  I  cried  out.  The 
Annamites  came  running  and  dragged  me  from 
under  the  palms  to  the  fire.  I  discovered 
several  black  worms,  about  two  inches  long 
crawling  on  me.  They  fastened  their  heads 
upon  an  object,  bringing  their  tails  up  to  the 
head,  and  repeating  the  operation,  they  moved 
along  with  surprising  rapidity.  Their  backs 
were  kept  curved  after  the  manner  of  an  out- 
raged cat  and  they  were  extremely  painful  if 
your  skin  was  reached;  for  immediately  the 
worm  began  the  operation  of  bloat- 
ing itself  with  your  blood. 

"Sangsues!  Sangsues!"  shouted 
the  natives  with  amusement;  and  it 
was  then  that  I  discovered  why  1 
could  not  sleep  under  trees.  The 
worms  were  leeches  that  live  on  the 
branches  and  drop  on  their  prey  at 
night.  Their  bites  are  very  deep  and 
the  blood  may  run  for  fifteen  minutes  before  it 
can  be  stopped ;  and  the  deadly,  recurring  forest 
fever  often  results  from  them. 

With  the  crack  of  dawn,  we  were  jolting  and 
rocking  again.  We  left  the  valley  country  and 
began  toiling  up  crooked,  mountain  roads. 
The  jungle  gave  way  to  pine  trees,  and  tall 
mountains  frowned  down  upon  us  from  all 
sides.  Mile  after  mile  and  hour  after  hour 
went  by  without  the  slightest  trace  of  man.  We 
seemed  to  be  the  only  people  in  the  world. 

As  the  forenoon  lengthened,  we  reached  a 
great  plateau,  and  in  the  distance  a  black  spot 
was  pointed  out  as  our  objective.  Only 
glimpses  of  the  fort  could  be  seen  from  time 
to  time  through  the  large  pine  trees  and  I  was 
not  prepared  for  the  formidable  structure  that 
suddenly  appeared,  dominating  a  large  vacant 
plain  from  the  top  of  a  knoll.  The  fort  looked 
for  all  the  world  like  a  copy  of  the  old  prints  I 
had  seen  of  the  stockade-stronghold  of  the 
Pilgrim  Fathers  at  Plymouth.  A  dry  moat 
surrounded  the  post.  On  the  inside  bank,  long 
pointed  posts  stuck  out  at  an  angle  of  forty-five 
degrees.  Then  came  a  tall,  pointed  stockade 
broken  at  frequent  intervals  with  enfilading 
towers.  At  the  corners  were  tall  look-out 
posts.  .  Bayonets  flashed  at  intervals  along  the 
top  of  the  stockade.  A  French  flag  hung  from 
a  tall  pole. 

We  crossed  the  open  space,  which  I  noticed 
must  have  been  prepared  for  aeroplanes  and, 
as  we  approached,  a  bugle  sounded.  A  draw- 
bridge was  lowered  and  a  French  lieutenant 


An  SOS  in  the  Jungle  of  Indo-China 


45 


advanced  to  greet  me.  A 
few  minutes  later,  1  was  in 
the  officers'  quarters  trying 
to  discover  some  part  of 
my  body  that  did  not  ache 
from  the  vibrations  of  the 
ox  cart,  and  quenching  my 
thirst  with  one  of  those 
long,  cold  ones  that  make 
you  think  that  all  has  not 
been  in  vain. 

The  lieutenant,  Gobert 
by  name,  was  a  slim, 
medium-sized  man  bearing 
the  tan  that  comes  only 
from  years  of  life  in  the 
tropics.  He  was  about 
thirty  years  old  and  his 
plain,  khaki  uniform  did 
not  have  the  vestige  of  a 
decoration,  a  sharp  con- 
trast to  the  gay  bosoms  of 
the  Colonial  officers  I  had 
seen.  His  eyes  had  fol- 
lowed mine  and  a  slight 
blush  suffused  his  face. 

"  I  was  one  of  the  few 
Colonials  that  - understood 
the  Mois  and  were  kept 
here  during  the  entire  war 
to  prevent  the  natives  from 
being  carried  away  by 
German  propaganda.  I  am 
still  a  lieutenant  and  have 
yet  my  laurels  to  win." 

The  lieutenant  -  had 
spoken  frankly  and  pleas- 
antly. I  felt  that  1  was  go- 
ing to  like  him  immensely. 

"  From  what  I  have  already  heard  about  you 
and  the  Mois  last  year,  I  would  say  that  your 
laurels  have  grown  into  a  large-size  tree,"  1 
hastened  to  answer. 

Lieutenant  Gobert  laughed,  replying:  "The 
Mois  are  extremely  interesting.  They  have  no 
place  in  history  and  have  apparently  always 
lived  in  the  mountains  of  Annam.  The  fact 
that  they  have  been  uncontaminated  by  sur- 
rounding races  is  probably  due  to  the  fact  that 
the  Annamites  of  the  coast  think  the  mountains 
are  the  abiding  place  of  the  worst  devils,  and 
the  Mois  are  certain  that  sure  death  lurks  on 
the  plains.  As  a  result,  the  Mois  are  perhaps 
the  most  uncivilized  people  in  the  world.  But 
enough  of  this:  it  is  nearly  dinner  time." 


A  CORNER  OF  THE  DEFENSES  OF  KON  TUM 

Showing  the  stockade  with  its  sharp-pointed  posts,  set 
like  bayonets  against  a  possible  attack  by  man  or  beast 


In  going  to  my  quarters,  I  discovered  that  the 
buildings  were  in  the  form  of  a  square  and  could 
be  joined  together  by  inserting  sections  of 
stockade,  thus  presenting  a  second  line  of 
defence.  The  feudal  atmosphere  of  the  place 
and  the  Annamite  soldiers  with  their  conical 
hats,  long  bayonets  and  vivid  red-wrapped 
leggings  above  their  bare  feet  thrilled  me  with 
delight.  I  was  comfortably  quartered  and 
given  an  orderly.  The  place  was  a  veritable 
museum  of  strange  instruments  of  war,  and  it 
was  with  a  sense  of  regret  that  I  abandoned  a 
bamboo  arrow-gun  to  follow  my  orderly  to  the 
mess  quarters.  We  passed  through  a  charm- 
ing garden  to  a  large  house,  evidently  of  Moi 
pattern,  raised  off  the  ground  about  ten  feet  and 


46 


Radio  Broadcast 


having  a  wide  porch  running  entirely  around  it. 
On  one  side,  a  snowy  white  table  was  already 
set  and  the  interior  of  the  structure  was  the 
most  perfect  man's  lounging  room  1  have  ever 
seen,  with  huge  fire-place,  deep  chairs,  hunting 
trophies  and  a  riot  of  velvety  skins.  It  was 
the  only  spot  in  the  post  that  did  not  breathe 
war. 

Our  dinner  was  delicious,  and  when,  as  a 
climax,  a  heaping  dish  of  luscious  strawberries 
and  cream  was  brought  in,  visions  of  home  and 
Mother  flashed  before  me.  1  was  told  that  the 
post  was  at  an  altitude  of  five 
thousand  feet  and  that  temper- 
ate zone  products  flourished  on 
the  plateau. 

We  sat  there  a  long  time, 
watching  the  afterglow  of  the 
tropical  sun  on  the  mountain 
tops,  and  planning  my  hunting 
trip.  It  was  decided  that  we 
would  take  elephants  on  the  fol- 
lowing morning  and  visit  the 
neighboring  Moi  village  where 
we  would  arrange  for  the  killing  of  a  buffalo, 
the  building  of  a  "kill"  in  which  to  wait 
for  the  tiger,  and  the  engaging  of  a  number 
of  Mois  to  assist  us  in  the  proposed  hunt. 
While  waiting  six  or  seven  days  for  the  slain 
buffalo  to  become  tender  enough  to  appeal  to 
the  delicate  senses  of  a  well-brought-up  tiger, 
1  was  to  be  initiated  into  the  excitement  of 
electric  searchlight  hunting  at  night  and  the 
dangerous  pastime  of  shooting  elephants. 

We  were  interrupted  by  a  pretty  young  girl 
clad  only  in  a  colored,  native  skirt.  Her  hair 
stood  out  at  least  ten  inches  all  around  her  head 
and  her  eyes  were  so  black  that  I  was  startled. 

Lieutenant  Gobert  spoke  to  her  in  her  native 
tongue.  The  girl  advanced  shyly.  After  a 
short  conversation,  she  made  me  the  religious 
Lai  courtesy  of  Annam  and  glided  noiselessly 
out  of  the  room,  her  dark,  brown  body  seeming 
to  fuse  into  the  darkness. 

The  French  officer  laughed  before  making 
any  explanations. 

"That  was  Pocahontas,  my  Moi  wife. 
Come,"  said  he,  rising,  "  Duquesne  will  be  try- 
ing to  get  us  on  the  radio.  Let  us  go  to  the 
operating  room  and  I  will  tell  you  the  story  of 
Pocahontas  on  the  way." 

Once  out  of  the  dark  garden,  the  lieutenant 
continued: 

"  Most  of  the  time  there  are  only  two  white 
officers  in  a  post  like  this.    At  the  present 


moment,  I  have  a  garrison  of  only  sixty  An- 
namites,  since  my  colleague,  Sous-Lieutenant 
Lancelin,  and  the  rest  of  the  force  is  fifty  kilo- 
meters away  on  some  surveying  work.  Our  only 
communication  with  this  force  is  by  fire.  At  ten 
o'clock  we  will  mount  the  observation  tower  and 
look  for  his  signal  that  all  is  well.  After  you 
have  done  over  six  years  of  this  kind  of  service, 
with  only  one  leave  in  France,  you  will  perhaps 
understand  how  all  of  the  books  in  the  world 
will  cease  to  be  the  companion  that  nature  has 
intended  every  man  to  have. 

"The  Mois  are  very  tricky; 
you  never  know  when  and  how 
you  are  going  to  hurt  their  feel- 
ings. About  two  years  ago,  I 
was  unfortunate  enough  to  kill 
one  of  their  sacred  bulls  acci- 
dently  while  hunting  at  night. 
I  was  instantly  seized  and  con- 
demned to  be  thrown  to  the 
elephants,  which  are  instructed 
in  the  playful  art  of  throwing 
humans  high  into  the  air,  catch- 
ing them  on  their  tusks  and  then  kneeling  on 
what  is  left  after  the  first  operation.  This  girl 
you  have  just  seen  pleaded  with  her  father,  the 
chief,  for  clemency — I  had  previously  tried 
to  buy  her  for  a  wife — but  the  old  man  had  re- 
fused. So  earnest  was  she  in  my  behalf  that 
the  father  allowed  me  to  go.  A  few  days  later 
1  discovered  the  little  princess  hidden  in  my 
room :  she  had  run  away  from  her  tribe  and  said 
that  she  only  wished  to  serve  me  as  long  as  1 
wanted  her.  I  finally  struck  a  bargain  with 
her  father,  but  he  swears  that  he  will  throw  her 
to  the  elephants  if  she  ever  goes  back  to  him. 

"This  all  sounds  like  a  fairy  tale,  but  I  have 
grown  to  love  her  and  wonder  what  1  can  do 
with  her  and  what  will  become  of  her  when  1 
am  transferred  home.  I  call  her  Pocahontas 
because  Duquesne  interested  me  in  American 
history  some  time  ago  and  the  story  of  Captain 
John  Smith  and  the  Indian  princess  seemed 
to  resemble  my  case  somewhat." 

As  we  entered  the  receiving  room,  an  operator 
was  busy  receiving  a  message.  1  found  that 
the  radio  set  was  a  small  one,  not  good  for  over 
one  hundred  and  fifty  miles  under  the  most 
favorable  conditions,  but  compact  and  just  the 
thing  for  an  outpost  like  Kon  Turn.  Lieute- 
nant Gobert  read  me  the  gist  of  the  message  al- 
ready received.  Most  of  it  was  world  news  but 
Duquesne  had  slid  in  the  baseball  scores  sent 
out  by  Cavite  for  my  benefit.    It  was  wonder- 


An  SOS  in  the  Jungle  of  Indo-China 


47 


ful !  Here  we  were  lost  in  the  wilds  of  Darkest 
Asia,  yet  we  figured  out  that  the  baseball 
crowds  in  New  York  were  still  on  their  way 
home. 

When  the  native  had  ceased  receiving,  1 
asked  the  lieutenant  for  permission  to  send  a 
message  to  Duquesne.  "  Pittsburgh— Pitts- 
burgh!" 1  flashed  out  over  the  jungle  wastes, 
experiencing  a  thrill  of  pleasure  at  the  snappy 
crack  of  the  spark.  As  quick  as  a  flash  the 
reply  came  back:  "  Heinz  57." 

After  a  few  minutes  of  exchange  of  compli- 
ments, 1  reluctantly  followed 
Gobert  to  the  look-out.  At  ten 
sharp,  a  red  glow,  that  increased 
suddenly  and  then  slowly  died  out, 
appeared  on  the  far  horizon.  The 
lieutenant  touched  an 
electric  button  and  an 
electric  searchlight  above 
us  answered  the  signal. 
That  was  all;  but  the  lights  had 
sent  a  message  that  was  full  of 
meaning.  1  could  not  help  admir- 
ing these  men  who  were  consecrat- 
ing their  lives  to  the  demands  of  their  country 
and  carrying  out  their  orders  in  the  midst  of  a 
hostile  country  that  might  swallow  them  up 
at  any  moment. 

Next  morning,  shortly  after  daybreak, 
Lieutenant  Gobert  called  for  me  with  two  large 
elephants  bearing  protected  baskets.  Poca- 
hontas was  there  also,  stroking  one  of  the 
beasts  fondly.  She  had  come  to  see  her  master 
off.  Her  shyness  had  disappeared  and  I  was 
greeted  with  an  expansive  smile.  There  were 
five  armed  men  in  the  first  basket,  not  counting 
the  driver,  who  sat  pompously  on  the  ele- 
phant's head.  We  mounted  the  second  ele- 
phant and  were  joined  by  three  more  soldiers, 
making  twelve  of  us  altogether.  There  were 
enough  bayonets  sticking  out  of  the  baskets  to 
frighten  most  any  creature.  The  lieutenant 
gave  a  few  orders,  waved  good-bye  to  Poca- 
hontas, and  we  were  off. 

"She's  a  funny  girl,"  Gobert  remarked  with 
a  smile,  having  doubtless  followed  my  eyes. 
"  1  have  given  her  all  kinds  of  European  clothes, 
but  she  refuses  to  wear  them,  as  she  says  that 
neither  her  mother  nor  her  grandmother  ever 
wore  anything  like  them.  If  she  ever  sees  a 
white  woman,  perhaps  she  will  change  her 
mind."  • 

It  took  me  a  few  minutes  to  become  accus- 
tomed to  the  rather  uncomfortable  toddle  of  the 


elephant,  and  for  a  while  I  had  grave  fears  for 
my  breakfast.  After  leaving  the  stronghold, 
we  first  crossed  the  great  open  space  that  lay 
before  it.  Lieutenant  Gobert  went  on,  waving 
toward  the  plain: 

"The  maintenance  of  this  field  absolutely 
free  of  all  plants  capable  of  hindering  a  plane 
is  my  greatest  charge,  because,  if  the  Mois 
should  suddenly  rebel,  I  count  absolutely  upon 
the  assistance  of  planes,  as  there  are  no  troops 
available  that  could  get  here  quick  enough 
in  an  emergency." 

"Have  the  Mois  any  firearms?" 
I  inquired. 

"No;  but  they  have  bamboo 
guns  that  shoot  extremely  dan- 
gerous poisoned  darts.  Also,  they 
are  very  accurate  with  blow-guns. 
They  have  no  fear,  wishing  to  die 
in  war,  as  it  assures  them  of  the 
favor  of  the  gods.  It  is  no  sinecure 
fighting  hundreds  of  these  natives 
with  a  few  guns  and  a  limited 
quantity  of  ammunition  that  de- 
teriorates more  rapidly  than  it 
can  be  replaced  in  this  tropical  climate." 

"It  is  very  fortunate  that  you  have  a  radio 
set,"  I  remarked. 

"I  should  say  so;  the  radio  is  really  our 
protector.  You  think  that  I  am  isolated  now; 
just  think  how  much  more  difficult  the  position 
of  my  predecessor  was  before  the  days  of  the 
radio!" 

We  had  plunged  into  the  forest.  Large  pine 
trees  lined  the  roads  interspersed  by  tropical 
foliage  in  the  low  places.  The  elephants  fas- 
cinated me  as  they  tore  down  all  the  low,  hang- 
ing limbs  that  would  otherwise  have  scraped  our 
car.  In  one  place  we  passed  a  curious  collec- 
tion of  houses  surrounded  by  a  high  paling  of 
tree  trunks.  Wicker  roofs  rose  sharply  from 
their  narrow  bases  and  met  forty  feet  overhead 
like  the  edge  of  a  razor.  Colored  woods  were 
worked  into  the  roofs  in  peculiar  designs.  I 
was  told  that  each  house  represented  a  family 
vault,  some  of  them  containing  twenty  wrapped 
bodies;  and  the  strong  stockade  was  to  prevent 
the  dead  from  being  consumed  by  tigers. 

Shortly  afterward  we  reached  a  village  of 
many  houses  clustered  around  a  large  square. 
They  were  all  made  of  grass,  rested  on  piles 
from  eight  to  ten  feet  from  the  ground,  and  had 
flat  sloping  roofs.  Upon  our  approach,  crowds 
of  naked  children,  and  natives  clad  only  around 
the  centre  of  the  body,  swarmed  down  the  lad- 


48 


Radio  Broadcast 


protested  violently,  turning 
on  their  heels  to  go  away. 
It  was  then  1  realized  that 
money  was  an  unknown 
article  to  these  simple  na- 
tives. Lieutenant  Gobert 
produced  some  pieces  of 
cloth,  beads,  and  brass 
bracelets  which  were  di- 
vided among  them.  Not 
even  then  did  they  smile. 
Their  stoicism  was  most 
disagreeable  and  I  realized 
what  unpleasant  folk  they 
would  be  if  aroused. 

We  were  soon  again  on 
the  march,  our  Moi  guides 
following  after.  1  was  told 
by  Gobert  to  watch  out 
for  the  Chief's  elephants, 
as  we  were  soon  to  pass 
ders  of  their  houses  and  curiously  inspected  us,  them.  Great  snorts  greeted  us  as  we  came 
always  keeping  at  a  respectable  distance.  At  to  several  strong  stockades  almost  obscured 
the  far  end  of  the  square  was  a  building  of  con-  by  clouds  of  dust.  I  was  greeted  by  one 
siderable  proportions  which  my  conductor  an-  of  the  strangest  and  most  awful  sights  of 
nounced  was  the  domicile  of  the  Chief.  We  my  life.  Ten  elephants  with  long,  curved 
had  hardly  time  to  descend  from  our  elephants  tusks,  the  ends  of  which  had  been  sharpened  by 
before  the  great  man  appeared,  protected  *by  the  addition  of  steel  points,  were  throwing  grass 
several  extraordinary  muscular  soldiers  armed  manikins  into  the  air  and  catching  them  deftly 
with  spears,  grass  shields,  and  bow-guns.  on  the  ends  of  their  tusks.    After  doing  this 

The  Chief  was  dignity  itself  in  a  native  woven  several  times,  they  cast  what  was  left  of  the 
shirt,  black  towel  tied  around  his  head  with  its  forms  on  the  ground  and  trampled  them.  •'■  The 
ends  flapping  on  either  side,  several  strings  elephants  were  undergoing  their  daily  training, 
of  beads  around  his  neck,  round  pieces  of  gold  in  The  forest  soon  became  so  dense  that  we  had 
the  lobes  of  his  ears,  and  a  long  double  piece  of  to  dismount  our  elephants.  Gobert  superin- 
wire  from  some  European  cooking  utensil  tended  the  killing  of  an  old  buffalo,  and  a  blind 
stuck  through  his  twisted  hair  at  a  rakish  was  made  from  where  we  were  to  shoot. the 
angle.  great  cat  when  he  had  been  attracted  by  the 

Lieutenant  Gobert  addressed  him  in  his  own  odor  of  the  dead  beast.  The  huge  buffalo,  al- 
language,  presenting  him  with  a  package  of  though  weighing  over  two  thousand  pounds, 
cigarettes.  Not  a  trace  of  a  smile  broke  his  was  chained  to  a  tree  to  prevent  him  from  being 
feature  or  those  of  his  attendants  during  the     dragged  off  by  the  tiger. 

interview.  Suddenly  he  made  a  signal,  turned  The  following  night  we  started  on  our  first 
and  entered  the  house,  leaving  us  to  ourselves,  hunt.  Gobert  fitted  me  out  with  an  electric 
Gobert  announced  that  we  had  been  promised  searchlight  that  was  fastened  to  my  hat  and 
a  number  of  Mois  but  they  would  have  to  be  connected  with  some  batteries  strapped  to  my 
paid  in  advance.  At  that  instant  a  number  of  belt.  1  was  then  given  a  lecture  on  eyes:  red 
stalwart  men  advanced.  1  took  out  my  purse,  eyes  announced  a  member  of  the  cat  family: 
insisting  on  paying  the  necessary  costs.  Lieute-  if  they  were  small  and  close  together  it  would 
nant  Gobert  burst  into  laughter,  directing  me  be  a  leopard,  but  if  they  were  large  and  far 
to  offer  each  native  a  couple  of  Indo-China  bills,  apart  it  would  be  a  tiger.  On  the  other  hand, 
The  men  took  the  money,  examined  it  coolly,  if  the  eyes  were  green,  they  belonged  to  a  mem- 
and  handed  it  back  to  me.    The  lieutenant     ber  of  the  deer  family. 

explained  that  the  bills  were  in  payment  for  Trying  to  keep  this  information  in  my  mind, 
their  work  as  guides,  but  they  immediately     I  plunged  with  Gobert  into  a  jungle  path,  fol- 


Courtesy  of  the  French  Colonial  Digest 


A   BIT  OF  THE  COUNTRY  WEST  OF  QUI  NHON 
Once  in  the  tangle  of  tropical  growth  beyond  the  falls,  it  is  impossible  to  see 
more  than  a  few  feet  in  any  direction,  and  it  is  dark  and  strangely  silent 


An  SOS  in  the  Jungle  of  Indo-China 


49 


lowed  by  several  Mois.  1  was  told  to  keep  my 
searchlight  flashing  on  the  trees  to  anticipate 
any  lurking  panthers  while  my  companion  was 
to  cover  the  ground,  since  he  did  not  care  to  run 
the  risk  of  my  killing  a  sacred  bull  as  had 
happened  before  with  disastrous  results.  All 
of  the  awful  sights  1  had  ever  seen  paled  in  the 
terrible  aspect  assumed  by  the  snarled,  dark, 
dank  jungle  that  closed  in  upon  us.  The  hang- 
ing vines,  apparently  brought  to  life  by  the 
flashing  searchlights,  looked  like  writhing 
snakes  waiting  to  clasp  us  in  their  clammy 
embrace.  Owls  kept  me  on  the  jump  as  their 
eyes  would  flash  like  a  match  in  the  night  as 
they  flew  before  us. 

Suddenly  two  lights  shone  before  me  and 
disappeared  before  I  could  decide  whether  they 
were  green  or  red.  Two  more  followed  to  the 
left;  and  still  two  more  to  the  right.  I  brought 
my  rifle  to  my  shoulder  but  Gobert  whispered 
in  my  ear  that  they  were  deer  and  not  to  shoot 
as  it  would  frighten  the  big  game  we  were  after. 
I  have  never  seen  anything  prettier  than  the 
lovely  animals  as  they  slunk  away  into  the 
woods  after  having  been  momentarily  hypno- 
tized by  our  searchlights. 

We  came  to  a  branch  in  the  trail  and  I  was 
told  to  take  the  one  on  the  left  until  it  met  the 
other  a  few  hundred  yards  ahead.  I  had  not 
followed  it  long  before  I  came  to  an  open  space. 
I  heard  a  noise,  and  flash- 
ing my  light  in  the  direction 
of  the  disturbance  I  found 
myself  looking  into  a  pair 
of  huge  eyes.  A  second 
later  I  had  fired.  There 
was  a  terrific  crash.  1  care- 
fully went  forward,  expect- 
ing to  see  a  great  tiger 
stretched  out  on  the 
ground.  Finally,  the  light 
revealed  my  prey.  I  be- 
came transfixed  with  terror: 
a  huge  animal  lay  before  me 
with  several  Mois  shrieking 
beside  it.  Upon  seeing  me 
they  fled,  followed  by  our 
own  escort,  and  I  was  left 
alone — alone  with  a  dead 
sacred  bull. 

A  moment  later  Lieuten- 
ant Gobert  rushed  up. 
When  he  saw  what  had  hap- 
pened, he  seemed  to  turn  to 
stone.    Not  a  word  did  he 


utter  after  his  first  ejaculation:  he  stood  mo- 
tionless looking  at  the  bleeding  animal  before 
him.  I  tried  to  explain  how  1  had  been  sure 
that  nothing  in  the  world  but  a  tiger  could  have 
had  such  large  eyes;  how  terribly  I  felt  about 
it.  But  he  heard  me  not,  and  1  lapsed  into 
silence,  my  intuition  telling  me  that  the  conse- 
quence of  my  error  would  be  disastrous.  Sud- 
denly he  turned  on  his  heel  with  a  curt  "  Come; 
we  must  act  quickly." 

Without  another  word  I  followed  him  to  our 
elephant  and  suffered  the  torments  of  the 
damned  on  our  trip  home.  Gobert  smoked 
one  cigarette  after  another,  often  not  waiting 
for  one  to  be  consumed.  The  frightful  conse- 
quences following  the  killing  of  a  bull  two  years 
before  flashed  though  my  brain  with  foreboding 
vividness.  I  could  think  of  nothing  but  being 
tossed  aloft  by  furious  elephants,  and  of  fruit- 
less radio  SOS  calls. 

Upon  our  arrival  at  the  fort,  Gobert  led  me 
immediately  into  the  radio  room  and  carefully 
locked  the  door.  He  gave  me  a  pad  and  pencil, 
and  proceeded  to  give  me  directions. 

"There  is  only  one  thing  to  do:  I  must  go  to 
the  Chief  personally  and  forestall  any  religious 
uprising  that  may  follow. 

"Nothing  of  the  kind;  it  is  1  who  must  bear 


the  consequences," 
"  You  could  do 


1  interrupted. 

nothing,  and  besides,  you 


STRIKING  INTO  THE  DENSEST  JUNGLE 
A  hunting  party  out  after  tiger.    The  journey  would  be  practically  impossible  on 


foot,  but  the  lumbering,  pitching  elephants  are  excellent  mounts  for  this  sort  of 
work— if  you  are  a  good  sailor 


50 


Radio  Broadcast 


must  take  charge  here  until  the  other  detach- 
ment can  get  back.  You  will  at  once  keep  a 
fire  signal  going  until  answered  by  my  lieute- 
nant. Then  you  will  keep  at  this  radio  set 
until  you  can  get  Qui  Nhon.  They  do  not  us- 
ually take  messages  before  7  a.m.  but  you  must 
call  every  five  minutes  all  night  in  the  hope 
that  for  some  reason  that  God  only  knows  Qui 
Nhon  may  be  able  to  pick  up  your  call.  You 
will  tell  them  of  what  has  happened  and  to  send 
aeroplanes  at  once,  for  there  is  no  time  to  lose. 
If  1  don't  come  back,  have  the  planes  bomb  the 
Mois.  But  in  no  event  open  the  gates  of  the 
fort  until  the  planes  or  Lieutenant 
Lancelin  arrive." 

I  protested,  warning  him  of  his 
danger,  but  was  finally  convinced 
that  he,  knowing  the  Chief,  was 
the  person  to  go.  With  a  last  few 
directions  and  a  warning  not  to 
tell  "Pocahontas"  where  he  was 
or  what  had  happened,  he  was 
gone.  He  was  to  take  one  ele- 
phant and  five  armed  men,  one  of 
which  was  to  drop  off  the  elephant 
just  before  entering  the  Moi  camp  and  return 
to  the  fort  with  news  of  the  party's  fate. 

A  moment  later  the  Annamite  radio  man 
came  in  and  we  began  our  frenzied  attempt  to 
call  Qui  Nhon.  The  soldier  was  visibly  fright- 
ened, although  he  did  not  know  just  what  had 
happened,  and  I  felt  that  the  small  Annamite 
garrison  would  not  hold  if  attacked  by  the  Mois. 
I  Suddenly  there  was  a  crash  and  the  sky 
seemed  to  split  from  one  end  to  the  other.  I 
was  dazed  by  the  light.  The  heavens  opened 
and  a  storm  of  such  magnitude  as  I  had  never 
conceived  broke  upon  us.  The  current  had  to 
be  turned  off  and  there  we  sat  in  total  darkness 
hour  after  hour,  helpless  and  unable  to  use  the 
instruments  before  us.  Never  have  I  seen  such 
flashes  of  lightning,  such  blasts  of  wind  and 
rain.  The  signal  soldiers  reported  that  no 
answer  from  the  surveying  party  had  been  seen 
and  the  searchlight  was  now  useless.  1  or- 
dered a  number  of  barrels  of  crude  oil  to  be  set 
afire  as  help  must  be  had.  The  Annamite  said 
that  electrical  storms  sometimes  kept  up  for 
several  days  and  1  trembled  when  I  thought 
that  1  might  be  prevented  from  soliciting  help 
by  radio.  It  was  simply  up  to  Providence, 
and  we  kept  up  our  ominous  vigil,  hoping  and 
praying  that  the  storm  would  cease  at  the  break 
of  day. 

The  girl  came  in  to  inquire  for  the  lieutenant. 


I  sent  her  away  with  some  excuse.  A  few  mo- 
ments later  the  Annamite  called  my  attention 
to  the  East  where  the  first  signs  of  day  were 
struggling  through  the  storm.  There  came  a 
blow  at  the  door  and  a  torn  and  water-soaked 
figure  fell  into  the  room.  It  was  Gobert's 
soldier,  who  had  struggled  several  miles 
through  the  storm  and  jungle.  His  condition 
was  pitiful.  After  a  breathing  spell,  he  was 
able  to  tell  us  between  gasps  of  terror  and  ex- 
haustion that  the  lieutenant  and  his  soldiers 
had  been  seized  by  the  Moi  chief.  The  soldiers 
were  to  be  thrown  to  the  elephants  and  the 
lieutenant,  owing  to  his  rank, 
would  receive  the  more  honorable 
death  of  being  tied  to  four  ele- 
phants which  would  then  be  driven 
to  the  four  opposite  points  of  the 
compass. 

A  scream  followed  and  Poca- 
hontas, who  had  been  concealed 
behind  the  door,  rushed  into  the 
room.  She  cried  that  she  had 
saved  Lieutenant  Gobert  once 
and  she  could  do  it  again.  Accord- 
ing to  the  custom  of  her  people  all  executions 
took  place  at  high  noon,  and  by  starting  at 
once  she  could  forestall  the  event.  1  told  her 
that  I  would  not  allow  her  to  go  as  her  father 
had  vowed  to  kill  her  if  she  ever  returned  to  his 
camp.  The  poor  girl  rushed  from  the  room 
crying  that  she  would  gladly  give  her  life  if 
she  could  but  save  the  lieutenant.  It  was 
necessary  to  have  the  girl  locked  up,  and  she 
struggled  and  shrieked  to  the  very  last. 

I  took  up  my  place  at  the  instrument  again. 
The  day  broke  with  a  rush,  sending  the  storm 
away  as  fast  as  it  had  come.  It  was  incredible 
that  such  a  calm  could  succeed  the  crashes  and 
downpour  of  the  night  so  suddenly.  I  turned  on 
the  current  and  sent  out  the  call  for  Qui  Nhon, 
one  thing  running  through  my  mind  again  and 
again — assistance  had  to  arrive  before  noon. 
It  was  an  hour  before  Qui  Nhon  was  scheduled  to 
receive  but  I  prayed  that  somehow  the  message 
would  be  heard.  A  half  hour  went  by.  And 
then  it  was  three  quarters.  My  wrist  watch 
showed  that  there  remained  barely  five  hours. 
I  wondered  what  could  be  done  if  I  could  not 
get  immediate  help.  It  was  impossible  to 
rescue  Gobert  with  the  small  detachment  at 
the  post.  The  poor  Annamite  was  no  longer 
capable  of  work;  he  was  almost  paralyzed  with 
terror  and  1  must  admit  the  situation  was  af- 
fecting my  own  nerves.  .aa&Tt 


An  SOS  in  the  Jungle  of  Indo-China 


5i 


Suddenly  there  came  a  buzz  in  my  ears  and 
a  moment  later  1  was  pounding  off  the  news  of 
our  predicament.  Then  I  had  to  wait  for  a 
reply.  An  hour  went  by.  Only  four  more 
hours  remained.  1  cursed  the  slowness  of 
officialdom.  Finally,  there  came  orders  to  get 
everything  in  readiness  to  receive  two  aero- 
planes that  had  already  started.  1  announced 
the  news  to  the  nervous  Annamites  and  disci- 
pline returned  immediately. 

Then  began  the  longest  wait  I  have  ever 
known.  My  eyes  went  from  my  watch  to  the 
eastern  sky.  Only  two  and  a  half  hours 
remained.  Duquesne  flashed  me  words  of 
encouragement.  An  Annamite  rushed  in  point- 
ing to  the  sky  and  words  fail  to  express  the  joy 
with  which  we  watched  the  progress  and  land- 
ing of  the  planes. 

A  Captain  rushed  forward  and  in  a  second  1 
had  explained  the  situation.  He  commanded 
me  to  enter  his  machine,  which  was  a  three- 
seated  bomber,  and  we  were  off,  followed  by 
the  small  plane  armed  with  a  machine-gun, 
speeding  for  the  Moi  village.  As  we  approached 
it,  we  could  see  a  crowd  in  the  square.  We 
dropped  a  bomb  which  went  off  with  a  terrific 
crash  as  it  struck  the  earth.  The  Mois  seemed 
to  disappear  into  thin  air.  The  small  plane 
made  a  nose  dive,  spraying  the  fleeing  natives. 
We  exploded  another  bomb  just  for  effect  and 


then  landed,  the  small  plane  circling  overhead 
to  protect  us. 

We  found  Lieutenant  Gobert  and  the  An- 
namites lying  in  a  row,  stripped  of  their  cloth- 
ing and  tied  to  thick  bamboo  poles.  A  Moi 
cart  was  found  and  we  were  soon  on  our  way 
back  to  the  fort.  When  we  were  safely  within 
the  walls,  the  two  planes  left  for  Qui  Nhon,  for 
the  Mois  must  be  kept  in  fear  of  them.  We  were 
also  told  that  reinforcements  were  on  the  way, 
and  were  also  greeted  upon  our  return  by  the 
surveying  party  that  had  seen  our  signal  of  the 
night  before. 

The  joy  of  Pocahontas  upon  seeing  her  mas- 
ter was  something  I  shall  never  forget.  Savage 
though  she  may  have  been,  she  was  as  brave 
and  devoted  as  they  make  them.  That  night, 
as  Gobert  and  I  communicated  with  Duquesne, 
it  was  with  a  sense  of  gratitude  that  we  handled 
the  small  radio  set.  Twice  it  had  saved  the 
life  of  the  lieutenant  and  his  tiny  garrison.  As 
for  me,  1  had  to  return  to  Qui  Nhon  contented 
with  my  one  shoot,  for  I  had  so  roused  the  na- 
tives that  it  was  impossible  to  continue  the 
hunt. 

Now,  as  1  sit  comfortably  by  my  radio  set  in 
a  staid  city  of  the  United  States,  I  cannot  help 
wondering  how  Gobert  and  Pocahontas  are 
faring  in  their  fort  in  the  wilds  of  the  Moi 
country. 


Adding  Two  Steps  to  Your  Aeriola 

Senior 

How  the  Job  is  Done,  and  What  the  Set  Will  Do 
By  JACQUES  H.  HERTS 


THERE  must  be  a  great  number  of 
radio  enthusiasts  who  started  their 
radio  education  as  I  did,  with  the 
well  known  Westinghouse  Aeriola 
Senior,  really  the  first  of  the  WD-i  i 
tube  sets.  To  all  of  these  this  description  of 
its  reconstruction  should  prove  interesting. 

1  acquired  my  Senior  last  April,  and  from  the 
first  hour  that  I  had  it  in  operation  I  knew 
that  I  had  been  bitten  by  the  "bug."  Re- 
sults were  interesting  from  the  start  and  after 
a  few  months  I  was  listening  to  half  the  conti- 
nent on  its  single  (and  then  almost  unknown) 
WD- 1 1  dry-cell  tube.  Being  a  "bug,"  I 
knew  that  ere  long  I  should  want  a  larger  and 
more  powerful  set,  and  my  present  set  is  the 
result. 

Several  months  ago  the  two-step  audio- 
frequency amplifier  to  match  the  Senior  made 
its  appearance  on  the  market;  but  my  old 
Senior  was  rather  shabby  looking  after  its 
hard  summer's  work  (though  it  still  was  reach- 
ing out  1,000  miles  with  regularity),  and  I  didn't 
like  the  idea  of  hooking-up  one  of  these  nice, 
new  shiny  amplifying  units  to  it,  so  1  decided  to 
use  what  1  could  from  the  Senior  and  build  an 


addition  to  it  of  two  stages  of  audio-frequency 
amplification,  the  entire  new  set  to  be  con- 
tained in  one  cabinet  and,  of  course,  to  operate 
entirely  on  WD-i  i  tubes. 

Not  having  the  necessary  equipment  to  do 
the  work,  I  drew  many  plans  and  had  them 
carried  out  by  a  well-known  radio  construction 
firm;  however,  the  work  is  quite  simple  and 
could  be  done  at  home  in  a  few  days  (and  quite 
a  bit  of  money  could  be  saved  on  the  job). 

The  new  parts  needed  and  their  prices  are  as 
follows: 


2  WD-ii  tubes   $13.00 

2  Transformers    .     .     .     ...     .     .  10.00 

3  Sockets                             .    .    .    .  1 . 50 

3  Rheostats                                .     .     .  1 .80 

3  Jacks   3.00 

3  Dials  -  .     .     .  1 . 50 

1  Variable  Condenser   2.50 

3  Dry  cells   1 .00 

go  Volts  of  "B"  batteries   5.00 

Panel  (7x24)  and  Cabinet    .     .     .     .  6.00 

Sundries — Buss  Bar,  Spaghetti, 

Binding  posts,  etc   2.00 


Total     .     .     .     .  •  .     .     .     .  $47.30 


FIG.  I 

This  is  the  receiver  built  according  to  the  author's  plan.  Everything  but  the  antenna  and  ground  leads 
and  the  loud  speaker  (or  phones)  is  within  the  cabinet.    This  receiver  is  both  attractive  and  practical 


Adding  Two  Steps  to  Your  Aeriola  Senior 


53 


The  prices  given  are  approximate.  If  you 
want  to  shop  around  a  bit,  you  can  reduce 
them  materially. 

You  will  note  that  I  specify  two  new  tubes, 


FIG.  2 

There  is  plenty  of  room  within  the  cabinet  for 
the  A  and  B  batteries  as  well  as  the  tuning  and 
amplifying  units.  Note  that  the  amplifying  trans- 
formers are  mounted  at  right  angles  to  each  other 

assuming  that  you  will  use  the  one  that  you  are 
using  with  your  Senior,  as  I  did.  Three  new 
sockets  and  rheostats  are  needed  as  the  ones 
on  the  Senior  will  not  be  suitable  for  your  new 
set.  Choose  dials  and  rheostats  that  match  up 
and  your  new  panel  will  present  a  neat,  pro- 
fessional appearance. 

I  retained  intact  the  Senior  tuning  element 
as  I  considered  that  the  heart  of  the  circuit,  the 
only  addition  being  the  .0005  variable  con- 
denser in  the  antenna  circuit  instead  of  the 
fixed  antenna  condenser  that  is  provided  in  the 
Senior.  This  gives  considerably  sharper  tuning 
with  better  selectivity  resulting.  That's  about 
all  you  can  use  of  the  Senior  with  the  exception 
of  the  phone  condenser  and  grid  condenser  and 


leak,  but  it  is  enough  to  form  the  basis  of  a  very 
fine  piece  of  apparatus. 

I  used  De  Forest  transformers  and  find  the 
results  excellent,  though  that  is  a  matter  of 
personal  choice.  Nearly  any  of  the  standard, 
well  made  audio  transformers  may  be  used 
with  the  WD-i  1  tube. 

Figure  1  shows  the  panel  arrangement.  The 
.0005  condenser  is  placed  at  the  extreme  left, 
next  comes  the  dial  for  the  main  variometer, 
and  next  the  tickler.  You  will  note  that  this 
arrangement  reverses  that  on  the  Senior.  It 
is  done  simply  by  turning  the  entire  tuning 
element  upside  down.  This  will  make  wiring 
somewhat  easier  and  is  a  bit  better  when  you 
come  to  tuning  the  set.  To  the  right  of  the 
panel  you  see  the  three  rheostat  knobs  with 
the  three  jacks  underneath  for  plugging  in  on 
signals  with  either  the  detector  alone  or  with 
one  or  two  stages  of  amplification. 

Figure  2  shows  the  interior  arrangement  of 
the  parts.  I  have  my  three  tube  sockets,  two 
transformers  and  all  battery  binding  posts, 
mounted  on  a  small  hard  rubber  base  panel  to 
the  right  of  the  tuning  elements.  I  had  my 
cabinet  made  large  enough  to  hold  three  stand- 
ard dry  cells,  comprising  my  A  battery  and  one 
45-volt  B  battery,  although  I  find  somewhat 
louder  signals  may  be  had  by  using  or  even 
90  volts  on  the  plates  of  the  amplifying  tubes, 
so  I  am  using  another  45-volt  B  battery  for 
which  there  is  not  room  within  the  cabinet. 
All  connections  are  inside  the  cabinet  with  the 


fig.  3 

The  two  variometers  are  included  in  the  Aeriola  Senior  unit  itself,  and  the  addition 
of  the  variable  condenser  and  amplifying  units  is  clearly  shown  in  this  diagram 


54 


Radio  Broadcast 


FIG.  4 

Here  w?  have  the  layout  of  the  main  and  amplifier  panels.  Notice  the  shielding,  made  of  sheet  metal,  on  the  main  panel, 
and  the  sturdy  brackets  used  to  fasten  the  two  panels  together.    All  the  binding  posts  are  located  on  the  amplifier  panel 


exception  of  this  extra  B  battery  and  the  silk- 
covered  antenna  lead  and  ground  lead.  The 
wiring  diagram  shown  in  Fig.  3,  together  with 
the  panel  and  arrangement  drawings,  should 
enable  any  one  to  duplicate  this  set.  So  much 
for  how  it  is  done. 

Now  for  what  it  will  do.  My  outside  an- 
tenna is  a  single  wire  70  feet  long  on  the  top  of  a 
seven-story  building  with  the  lead-in  to  my 
room  on  the  third  floor.  The  ground  connection 
is  eight  feet  long  to  the  cold-water  pipe.  1  also 
use  a  loop  aerial  consisting  of  15  turns  of 
Litzendraht  wire  spaced  \"  between  turns  on 
a  two-foot  loop.  I  have  used  a  Dubilier  socket 
as  an  aerial  with  excellent  results. 

1  list,  in  the  order  of  their  importance  to  me, 
the  set's  various  performances: 

Tone  Quality:  Excellent,  equal  to  the  best 
phonograph  1  have  ever  heard. 

Selectivity:  I  have  readily  tuned  in  (from 
New  York)  KYW,  WWJ,  KDKA,  and 
WGY,  while  either  WJZ,  WEAF,  WHN, 
or  WOR  were  going  full  blast. 

Volume:  Set  can  be  heard  all  over  our  eight- 
room  apartment.  Local  stations  come  in  loud 
enough  to  work  a  non-power  loud  speaker, 
using  the  loop.  This  is  one  feature  that 
appeals  to  me  particularly,  as  the  loop  cer- 
tainly tunes  sharp  and  clean  and  when  the 
summer  season  comes  again  should  prove 
very  useful  in  cutting  down  the  static. 


DX:  My  best  distance  so  far  is  WBAP  at 
Fort  Worth,  Tex.,  1400  miles,  air  line.  I  can 
probably  improve  this  as  1  continue  to  use 
the  set,  but  do  not  expect  any  tremendous 
increase  in  range  over  the  Senior.  Only  the 
first  stage  of  the  audio  amplification  will  be 
of  any  value  in  reaching  out  after  DX  sta- 
tions and  this  assistance  will  only  be  slight. 

The  advantages  of  the  set  are,  that  the  simple 
tuning  of  the  Senior  is  retained  to  a  large  de- 
gree, the  added  control  of  the  variable  con- 
denser does  not  complicate  tuning  very  much 
(after  a  few  days  you  will  hardly  notice  the 
change),  you  still  have  a  portable  set  (no 
storage  batteries),  and  you  have  fine  tone 
and  ample  volume,  fine  selectivity  and  good 
range. 

Just  one  little  hint.  I  found  after  a  few 
weeks'  operation  and  experiment  that  a  .0005 
fixed  condenser  shunted  across  the  secondary 
of  the  second  transformer  improved  the  tone 
quite  a  bit  and  did  not  cut  down  the  volume 
noticeably. 

I  have  purposely  avoided  laying  down  any 
hard  and  fast  directions  or  instructions  for  the 
construction  work.  1  am  merely  offering  a 
suggestion  of  what  can  be  done  with  an 
Aeriola  Senior  and  am  leaving  details  to  each 
individual's  ingenuity.  The  next  person  that 
attempts  the  same  job  will  probably  hit  upon 
some  little  wrinkle  or  improvement  that  1  did 
not  discover. 


What  Can  Be  Patented? 

By  ROGER  SHERMAN  HOAR,  A.B.,  M.A.,  LL.B. 

Former  Assistant  Attorney  General  of  Massachusetts 
Drawings  by  THOMAS  E.  MONROE 


N'  OT  every  bright  idea  is  patentable, 
and  not  every  patentable  idea  can 
be  made  use  of  by  its  originator. 
Without  any  further  introduction, 
let  us  roll  up  our  sleeves  and  plunge 
right  into  the  following  welter  of  words: 

U.  S.  Revised  Statutes,  Title  LX,  Sec.  4886.  Any 
person  who  has  invented  or  discovered  any  new  and 
useful  art,  machine,  manufacture,  or  composition  of 
matter,  or  any  new  and  useful  improvements  thereof 
not  known  or  used  by  others  in  this  country  before 
his  invention  or  discovery  thereof,  and  not  patented 
or  described  in  any  printed  publication  in  this  or  any 
foreign  country  before  his  invention  or  discovery 
thereof,  or  more  than  two  years  prior  to  his  appli- 
cation, and  not  in  public  use  or  on  sale  in  this  country 
for  more  than  two  years  prior  to  his  application,  un- 
less the  same  is  proved  to  have  been  abandoned, 
may,  upon  payment  of  the  fees  required  by  law, 
and  other  due  proceeding  had,  obtain  a  patent 
therefor. 

That  is  a  mouthful,  to  chew  and  digest !  But 
the  present  chapter  will  undertake  that  task. 
Let  us  start  with  a  few  definitions. 

An  "art"  means  some  distinct  method  or 
process.  The  word  "machine"  requires  no 
defining.  A  "composition  of  matter"  consists 
in  the  uniting  of  two  or  more  ingredients,  either 
chemically  or  physically,  to  produce  a  new  and 
homogeneous  mass.  A  "manufacture"  is  any- 
thing, made  by  man,  which  is  not  a  machine, 
a  composition  of  matter,  or  a  design. 

The  invention  must  be  new  and  useful. 
Novelty  consists  in  the  invention  not  having 
been  used  by  others  in  the  United  States, 
orpatented  or  de-scribed  in  any  printed  publica- 
tion in  this  or  any  foreign  country.  Yet  prior 
knowledge  or  use  abroad,  unknown  to  the  in- 
ventor, does  not  prevent  the  invention  from 
being  "new,"  even  if  such  foreign  use  was 
known  in  this  country.  This  shows  that,  in 
spite  of  the  language  of  the  above-quoted 
statute,  prior  knowledge  in  this  country  does 
not  prevent  novelty;  anid  we  shall  see  later  in 
this  article  that  even  prior  invention  in  this 
country  is  not  necessarily  fatal. 

An  invention  is  "useful,"  if  operable,  and  if 


not  frivolous,  nor  injurious  to  morals,  health  or 
good  order. 

The  Patent  Office  has  an  interesting  policy 
with  respect  to  perpetual-motion  machines, 
which  of  course  are  not  operable,  and  hence  are 
not  useful,  and  hence  are  not  patentable.  Un- 
fortunately it  is  impossible,  by  mere  argument, 
to  convince  the  inventor  of  perpetual  motion 
that  he  is  on  the  wrong  track.  So  the  Patent 
Office  adds  a  little  inducement  to  its  argu- 
ment, by  sending  a  personal  letter  to  the  poor 
deluded  scientist,  offering  him  his  choice  of  a 
rejection  if  he  persists,  or  a  return  of  his  filing 
fee  if  he  will  be  so  good  as  to  withdraw  his  ap- 
plication.   This  usually  works. 

Yet  many  ideas  as  weird  and  wild  as  per- 
petual motion  are  permitted  to  be  patented.  1 
know  of  one  leading  patent  attorney  who  has  a 
much-prized  collection  of  some  two  hundred 
freak  patents  of  this  sort. 

If  you  wish  some  light  humorous  reading,  I 
suggest  that  you  look  at  the  Official  Gazette  of 
the  Patent  Office  each  week  at  your  Public 
Library,  or  subscribe  to  it  at  five  dollars  a  year 
from  the  Public  Printer,  Washington,  D.  C. 
In  the  first  place,  this  magazine  is,  next  to  the 
Congressional  Record,  the  leading  funny-paper 
of  America.  In  the  second  place,  it  will  enable 
you  to  keep  in  touch  with  the  progress  which  is 
being  made  in  your  own  particular  line.  Some 
member  of  every  engineering  department 
should  certainly  be  assigned  the  very  entertain- 
ing job  of  reading  the  "O.  G.,"  which  very 
name  is  symbolic  of  the  surprised  joy  he  will 
experience. 

But  although  the  examiners  of  the  Patent 
Office  are  too  busy  to  head  -off  the  scores  of 
absolutely  absurd  and  unworkable  devices 
which  issue  every  year,  yet  they  occasionally 
balance  the  record  by  rejecting  some  perfectly 
workable  one.  "  If  this  be  treason,  make  the 
most  of  it,"  as  Patrick  Henry  once  said.  For 
example,  a  certain  aiming  device  for  big 
guns,  which  was  developed  during  the  late 
War,  was  thrice  turned  down  by  them  with 
much  sarcastic  comment,  in  spite  of  the  fact 
that  it  had  been  tested  and  approved  by  the 


56 


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INVENTION  CONSISTS  IN  THE  CONCEPTION 
And  the  selection  of  means  whereby  the  function  can  be 

Coast  Artillery  Board,  the  Field  Artillery 
Board,  the  Chief  Orientation  Officer  of  the  A. 
E.  F.,  etc.,  etc.,  and  had  won  an  official  U.  S. 
Army  contest  to  determine  the  most  accurate 
device  of  its  class.  Yet  the  patent  examiners 
thrice  ruled,  in  the  face  of  this  evidence,  that 
this  machine  could  not  possibly  work! 

Reverting  to  the  subject  of  patentability,  we 
find  that  there  is  an  important  legal  distinction 
between  "combinations"  (which  are  patenta- 
ble) and  "  aggregations  "  (which  are  not).  Sup- 
pose your  invention  consists  in  putting  together 
two  or  three  already-known  elements.  The 
mere  combining  of  old  machine  parts,  each 
operating  in  the  old  way,  and  accomplishing 
the  old  result,  is  an  aggregation,  and  hence 
unpatentable;  whereas,  if  a  new  result  be 
produced  by  the  joint  action  of  the  elements, 
artd  if  such  result  be  not  the  mere  adding  to- 
gether of  the  contributions  of  the  separate  ele- 
ments, then  there  exists  a  patentable  combina- 
tion. Ask  yourself:  Is  the  function  of  the 
whole  equal  to,  or  greater  than,  the  sum  of  the 


functions  of  the  parts?  If 
equal  to,  then  we  have  mere 
aggregation.  If  greater 
than,  then  we  have  com- 
bination. In  other  words, 
a  patentable  combination 
violates  that  fundamental 
axiom  of  geometry:  "The 
whole  is  equal  to  the  sum 
of  its  parts." 

Furthermore,  a  mere  idea 
is  not  patentable;  there 
must  also  be  the  means  for 
utilizing  it  practically. 
Newly  discovered  laws  of 
nature  are  not  patentable; 
invention  consists,  not  in 
discovering  them,  but  rather 
in  applying  them  to  useful 
objects.  A  good  definition 
from  a  very  recent  court 
decision  is:  "  Invention  con- 
sists in  the  conception  of  a 
function,  and  the  selection 
of  means  whereby  the  func- 
tion  can  be  operatively 
carried  out." 

Novelty  and  utility  alone 
are  not  enough  to  make  an 
idea  patentable,  but  there 
must  also  be  invention. 
That  is  to  say,  the  inventor 
must  have  displayed  more  ingenuity  than  could 
be  expected  of  the  average  skilled  person,  when 
confronted  with  the  same  situation.  It  is  not 
necessary,  however,  for  the  inventor  to  under- 
stand why  his  device  works,  provided  he  under- 
stands and  explains  how  it  works. 

Mere  simplicity  of  the  device  does  not  nega- 
tive invention;  but  rather  is  often  evidence  of 
the  very  highest  inventive  genius.  On  the 
other  hand,  mere  complexity  or  multiplicity  of 
parts  is  no  proof  of  invention.  Redhoeffer's 
famous  perpetual-motion  machine  attracted 
no  popular  attention  until  he  added  a  lot  of 
gears  and  buzzing  ratchets,  when  it  at  once  be- 
came a  nine-day  wonder;  but  all  this  noisy 
machinery  didn't  get  him  anywhere  with  the 
Patent  Office.  A  certain  gear  company  has  an 
advertising  machine  consisting  of  about  a 
thousand  of  their  products,  all  intermeshing 
and  actually  running;  certainly  ingenious,  and 
involving  great  mechanical  skill,  but  by  no 
means  patentable. 

A  few  further  sorts  of  improvements  which 


OF  A  FUNCTION 
operatively  carried  out" 


What  Can  Be  Patented  ? 


57 


are  not  patentable  are:  superior  form  or  finish; 
a  more  extended  application  of  an  old  idea;  en- 
larging or  strengthening;  changing  proportions; 
duplication  of  parts;  changing  the  location  of 
parts;  substitution  of  equivalent  materials;  or 
substituting,  for  some  part,  a  mechanical 
equivalent  which  performs  the  same  functions 
in  substantially  the  same  way,  thereby  ac- 
complishing substantially  the  same  result. 
Mechanical  devices  are  "equivalents"  when 
any  skilled  and  experienced  workman  would 
know  that  they  would  produce  the  same  results. 

The  omission  of  a  part  and  of  its  function  is 
not  invention;  but  the  omission  of  a  part,  with 
a  rearrangement  of  the  remaining  parts,  so  as 
to  perform  the  same  results,  is  invention.  So 
likewise  is  the  substitution  of  a  single  part  to 
perform  the  functions  of  two  or  more  former 
parts. 

The  best  way  to  determine  the  patentability 
of  your  invention  is  to  have  some  attorney 
make  a  search  of  the  prior  art  in  the  files  of  the 
Patent  Office  at  Washington.  This  will  cost 
you  at  least  twenty  or  thirty  dollars,  but  any 
search  costing  less  than  this  will  not  be  worth 
even  what  you  pay  for  it. 

Thus  it  will  be  just  as  cheap  for  you  to  pre- 
pare a  regular  patent  application  and  file  it  with 
a  twenty-dollar  fee,  and  then  let  the  Patent 
Office  make  your  search  for  you.  If  the  search 
shows  that  your  invention  has  been  anticipated, 
it  will  have  cost  you  no  more  than  a  search 
made  by  an  attorney.  If,  however,  the  result 
of  the  search  is  favorable, 
your  patent  will  already  be 
on  its  way  to  allowance  with- 
out further  expense. 
■  But,  before  doing  even 
this,  you  can  easily  make  a 
sort  of  search,  which  may  be 
productive  of  great  results  at 
practically  no  cost.  Copy 
the  patent  dates  from  a  few 
machines  of  your  own  class. 
Look  up  the  inventor's  name 
and  patent  number  under 
these  dates  in  the  bound  vol- 
umes of  the  Official  Gazette  in 
the  Public  Library.  If  any 
of  these  inventions  are  at  all 
like  yours,  send  ten  cents 
apiece,  with  the  name,  date 
and  number,  to  Mentzel  & 
Sterzer,  9 1 9  Washington  Loan 
&  Trust  Bldg.,  Washington, 


D.  C,  requesting  copies  of  these  patents,  and  a 
list  of  the  patents  which  were  cited  against  each, 
while  pending.  Enclose  an  extra  dollar  per 
patent,  for  this  latter  information.  When  they 
reply,  send  ten  cents  apiece  for  copies  of  the 
citations,  etc.,  until  finally  you  will  have  col- 
lected, at  nominal  cost,  enough  prior  art  to 
show  you  just  where  you  stand.  1  always  use 
this  method. 

You  will  save  a  lot  of  bother  by  using  govern- 
ment coupons  to  order  your  copies.  Such  cou- 
pons can  be  purchased  of  the  Patent  Office  in 
books  of  twenty  for  S2.00,  or  one  hundred  for 
$10.00. 

Let  us  now  consider  how  an  invention  can 
lapse.  An  inventor  forfeits  his  invention  by 
two  years'  public  use  or  sale  in  America  (by 
himself  or  others)  prior  to  his  applying  for  a 
patent;  or  by  abandonment. 

A  single  public  use  is  sufficient.  The  knowl- 
edge or  consent  of  the  inventor  is  immaterial. 
But  mere  experimental  use,  even  if  public,  is 
not  a  bar;  and  the  Courts  are  very  liberal  in 
construing  a  use  to  be  experimental. 

A  single  sale  is  sufficient.  Merely  placing 
on  sale  the  completed  machine  is  sufficient, 
even  if  no  sales  result.  But-  it  is  allowable  to 
sell  a  very  expensive  experimental  machine, 
without  this  barring  your  patent. 

An  inventor  can  likewise  forfeit  his  invention 
by  abandonment,  as  will  be  described  in  the 
next  article. 

Reverting  to  the  language  of  the  statute,  you 


INGENIOUS,   BUT  NOT  PATENTABLE 
A  collection  of  various  kinds  of  products  manufactured  by  a  gear  company. 
The  gears  actually  run,  but  the  machine  serves  no  useful  purpose 


5<3 


Radio  Broadcast 


EVEN   IF  NO  SALES  RESULT 
An  inventor  forfeits  his  invention  by  plac- 
ing on  sale  his  completed  machine  for  two 
years  prior  to  his  applying  for  a  patent 


will  see  that  only  the  inventor  or  discoverer  is 
entitled  to  a  patent  in  the  United  States.  The 
manufacturer  or  first  importer  cannot  get  a 
patent  here,  although  a  different  rule  prevails 
in  some  foreign  countries. 

You  will  also  see  that  the  invention  must  not 
have  been  previously  known  or  used  by  others. 
This  amounts  to  the  same  thing  as  the  state- 
ment to  which  the  inventor  must  subscribe  in 
his  official  oath:  namely,  that  he  is  the  original 
and  sole  inventor.  Just  what  do  these  words 
mean?  Strange  as  it  may  seem,  they  have  two 
entirely  distinct  meanings,  according  as  to 
whether  the  real  first  inventor  does,  or  does  not, 
apply  for  a  patent.  This  is  a  vital  distinction, 
and  may  well  be  the  determining  factor  in 
deciding  whether  or  not  to  apply  for  a  patent. 

Let  me  illustrate  this  point  by  the  imaginary 
case  of  a  certain  type  of  desk  invented  by 
Smith.  Suppose  that  Robinson,  several  months 
later  than  Smith,  independently  conceives  of 
exactly  the  same  invention. 

Case  i .  Suppose  that  both  Smith  and  Rob- 
inson apply  for  patents.  An  interference  is 
declared  in  the  Patent  Office,  and  each  is  re- 
quired to  produce  evidence  as  to  the  date  of 
conception  of  his  invention,  and  the  dates  of 


such  subsequent  acts  as  have  been  performed 
by  him  in  completing,  adapting,  and  perfecting 
it,  and  in  putting  it  into  use.  Such  dates  us- 
ually include  the  dates  of  (a)  conception,  (bj 
first  drawing,  (c)  first  written  description,  (d) 
first  disclosure  to  others,  (e)  first  full-size 
machine,  (f)  first  successful  operation,  and  (g) 
first  sale;  also  the  extent  of  use.  But,  although 
the  date  of  conception  is  the  really  important 
thing,  it  is  very  hard  to  prove  a  conception 
earlier  than  the  date  of  first  disclosure.  Fur- 
thermore, the  conception,  drawing,  description, 
and  even  disclosure  are  of  no  avail  unless  the 
invention  was  diligently  reduced  to  practice, 
i.  e.,  either  built  or  embodied  in  a  patent  ap- 
plication. Reduction  to  practice  will  be  dis- 
cussed more  at  length  in  the  next  article. 

Case  2.  Suppose  Robinson,  the  later  in- 
ventor, applies  for,  and  secures,  a  patent. 
Smith  tries  to  manufacture.  Robinson  sues 
Smith  for  infringement.  Smith  defends  on 
the  ground  that  Robinson  was  not  the  original 
and  first  inventor,  a  defense  specifically  allowed 
by  statute.  But  the  Courts  have  cut  down  this 
defense  by  limiting  the  admissible  evidence. 
Thus  Smith  must  prove  an  actual  successful 
use  of  the  machine,  or  a  sale  or  full  published 
description,  prior  to  Robinson's  mere  concep- 
tion. Even  proof  of  models  and  unpublished 
drawings  will  be  of  no  avail  to  Smith. 

Both  cases  show  the  importance  of  the  real 
first  inventor  speedily  applying  for  a  patent, 
if  he  wishes  to  retain  the  right  to  manufacture 
his  own  device. 

Let  us  now  consider  the  perplexing  question 
of  joint  inventors.  If  several  persons  work 
together  devising  a  new  piece  of  apparatus, 
which  of  them  should  be  included  in  the  ap- 
plication for  a  patent?  This  is  not  a  mere 
formal  question,  but  is  very  important,  for  a 
patent  issued  to  two  parties  is  invalid  if  one 
of  them  is  the  sole  inventor,  and  a  patent 
issued  to  only  one  of  two  joint  inventors  is 
likewise  void. 

This  is  particularly  important  in  interferences 
where  the  true  facts  are  almost  certain  to  be 
brought  out  in  the  course  of  proving  the  date 
of  invention.  It  is  impossible  either  to  add  or 
to  strike  out  an  inventor  by  amendment;  and 
so,  because  of  including  too  many  or  too  few 
names,  the  application  is  apt  to  be  disregarded, 
and  priority  awarded  to  inventors  who,  al- 
though later,  have  nevertheless  been  more 
careful  in  this  particular. 

Above  all,  do  not  include  the  name  of  your 


What  Can  Be  Patented? 


59 


chief  engineer,  out  of  mere  courtesy,  as  a  joint- 
inventor,  nor  the  name  of  your  draughtsman 
or  mechanic.  I  have  known  patents  to  be 
declared  void  for  each  of  these  causes. 

If  different  improvements  on  the  same  ma- 
chine are  invented  by  each  of  several  inventors 
separately  without  consultation  with  the  other, 
then  each  must  patent  his  own  contribution 
separately.  But  mutual  suggestions  and  im- 
provements constitute  a  joint  invention,  even 
if  the  contribution  made  by  each  is 
distinct  and  separate. 

Thus  when  a  claim  covers  a  series  of 
steps  or  a  number  of  elements  in  a 
combination,  the  invention  may  be 
joint,  even  if  some  of  the  steps  or  ele- 
ments were  contributed  by  one  in- 
ventor alone. 

On  the  other  hand,  the  suggestion  of  some 
features  by  another  than  the  patentee  will  not 
invalidate  the  patent,  if  the  final  result  repre- 
sents the  patentee's  own  combination  of  these 
suggestions  with  ideas  of  his  own. 

In  view  of  this,  it  may  be  desirable  to  patent 
a  device  in  the  name  of  the  last  contributor;  and 
this  is  perfectly  allowable  if  the  device  with  his 
last  contribution  would  be  patentable  as  an 
improvement  over  the  device  as  it  stood  just 
before  this  contribution. 

Lack  of  mechanical  skill,  and  the  consequent 
employment  of  another  to  work  out  the  details 
of  your  invention,  do  not  prevent  you  from 
being  the  sole  inventor. 

In  the  absence  of  an  express  agreement  be- 
tween the  joint  owners  of  a  patent,  either  of  the 
owners  can  make,  use,  and  sell  the  invention,  or 
grant  to  others  the  right  to  do  so,  without  re- 
gard to  the  proportionate  interest  which  the 
parties  may  own,  and  without  liability  to  his 
co-owners  to  share  his  profits  with  them. 

As  between  patent  attorney  and  client,  any 
suggestions  of  the  attorney  inure  to  the  benefit 


of  the  client.  In  a  recent  case  the  lawyer 
claimed  to  have  made  a  certain  invention  be- 
fore his  client  came  to  him  with  the  same  idea ; 
but  the  Court  awarded  the  patent  to  the  client. 
This  illustrates  the  need  of  care  in  choosing  an 
honest  lawyer,  a  point  which  will  be  further 
discussed  in  the  fourth  article. 

In  the  absence  of  an  express  agreement,  an 
employer  has  no  right  to  the  inventions  of  an 
employee,  even  though  the  device  was  built. 

tested,  and  patented  at  the  employ- 
er's expense,  and  even  though  the 
employee  was  hired  expressly  to  in- 
vent, in  which  latter  case,  however, 
the  Company  would  have  an  implied 
license  to  make,  use,  and  sell  devices 
embodying  the  inventions.  And  in 
any  event,  if  the  invention  was  ap- 
plicable to  the  employer's  business,  he  would 
have  a  right  to  use  the  device  in  his  own  shops. 

Accordingly  it  is  customary  for  employers 
to  insist  that  technical  employees  shall  agree 
in  writing  to  assign  all  inventions  made  during 
their  employment;  and  such  agreements  have 
always  been  sustained  by  the  Courts. 

An  agreement  to  assign  all  future  inventions, 
is  void;  but,  with  a  time  limit  or  even  a  limit  to 
a  certain  class  of  inventions,  it  is  perfectly 
valid.  Yet  everyone  will  tell  you  that  there 
must  be  a  time  limit  too,  even  in  the  latter 
case. 

In  my  old  home  town,  the  noble  redskins 
frequently  sell  a  piece  of  land  and  still  think 
that  they  own  it.  This  results  in  the  same  piece 
of  land  being  sold  several  times  in  succession, 
and  yet  still  being  claimed  by  its  original  Indian 
owner,  to  the  great  joy  of  some  local  lawyer. 
Hence  the  expression  "  Indian  Giver."  Some- 
what the  same  idea  frequently  prevails  among 
inventors,  so  let  me  state  in  closing  that,  if  you 
sell  a  patent,  it  is  gone,  and  even  you  can't 
manufacture  your  own  device  any  more. 


This  is  the  second  of  a  series  of  four  articles  dealing  with  patents. 
The  first,  "What  Good  is  a  Patent?"  appeared  last  month,  and 
Mr.  Hoar's  third  article,  entitled  "Protecting  Your  Invention," 
will  be  published  in  Radio  Broadcast  for  June. — The  Editor. 


LISTENING  TO  A  BROADCASTING  PROGRAM- 
This  is  said  to  be  the  first  hotel  in  America  to  equip  its 
guests  may  listen  when  they  wish  to,  but  are  not  disturbed- 


— AT  THE  HOTEL  BELLEVUE,  SAN  FRANCISCO 
— dining-room  with  radio.    By  using  individual  phones,  the 
— by  a  loud  speaker  when  they  prefer  to  talk — or  eat! 


A  Radio  Code  With  Eleven  Million 

Variations 

By  S.  R.  WINTERS 


WHEN  the  battleship  fleets 
of  the  Atlantic  and  Pacific 
engaged  in  maneuvers  in  the 
vicinity  of  the  Panama  Canal, 
in  March,  there  was  in 
operation  for  the  first  time  under  service  con- 
ditions an  apparatus  for  transmitting  radiotele- 
graph messages  in  a  code  capable  of  1 1,881,376 
variations.  The  invention,  the  work  of 
Edward  H.  Hebern  of  Oakland,  California,  is 
said  to  be  the  only  one  in  the  world  by  which 
wireless  communications  can  be  sent  by  a  code 
system  that  is  automatically  deciphered  and 
is  clothed  in  absolute  secrecy.  A  reward  of 
$5,000,  offered  to  the  Department  of  Justice 
many  months  ago,  contingent  upon  its  ability 
to  decipher  a  message  thus  transmitted,  has  not 
been  redeemed. 

This  machine,  for  which  more  than  seventy 
patents  have  been  issued  or  are  pending  in  all 
countries  of  the  world,  functions  in  conjunction 
with  a  small,  changeable  wheel  known  as  the 
"key  wheel"  or  "code  wheel."  A  statistical 
wizard  in  California  has  computed  the  possible 
changes  to  which  one  code  wheel  is  subject 
as  approaching  the  staggering  figures — 
40,303,146,321,064,147,046,400,000.  Be  that 
as  it  may,  this  tiny  wheel,  weighing  barely  twelve 
ounces,  contains  a  multiplicity  of  abbreviated 
electric  wires — twenty-six,  to  be  exact.  In 
either  side  of  this  wheel  are  also  twenty-six  aper- 
tures, with  an  equal  number  in  the  rim. 

Each  key  on  the  typewriter-like  keyboard  is 
wired  in  combination  with  other  letters  and 
they  are  responsive  to  a  slight  pressure  of  any 
of  the  letter  keys,  each  of  the  latter  being  en- 
ergized by  an  electro-magnet.  The  entire 
apparatus  is  electrically  operated,  the  arrange- 
ment of  the  complicated  wiring  containing  the 
secret  of  the  instrument.  A  dry  battery,  half 
the  size  of  one's  hand,  is  sufficient  to  operate 
the  machine  for  about  two  hours.  The  model 
on  demonstration  in  Washington,  D.  C,  em- 
ploys a  No.  750  Tungsten  battery.  As  a 
matter  of  fact,  any  source  of  electricity  is 
capable  of  operating  this  mechanism — a  six- 


volt  automobile  battery,  dry  cells,  or  direct  or 
alternating  current  from  a  1 10-volt  home  or 
office  circuit.  The  standard  code  machine, 
however,  is  equipped  for  operation  with  alter- 
nating current,  contact  being  made  with  a 
1 10-volt  circuit,  which  is  "stepped  down" 
to  twenty  volts  by  a  transformer  within  the 
stand  of  the  apparatus.  If  direct  current  is 
to  be  used,  a  special  transformer  is  supplied  for 
reducing  the  strength  of  the  electric  energy. 

The  operator  who  desires  to  transmit  wireless 
messages  according  to  this  code  system  writes 
what  he  has  to  say  in  plain  English  on  the 
keyboard.  The  code  wheel  on  the  sending 
device  transforms  the  words  into  a  jumble  of 
letters,  so  to  speak,  for  conveyance  through 
the  ether  by  radio.  Both  the  sending  and 
receiving  units  of  this  machine  are  combined, 
the  entire  outfit  weighing  barely  twenty-five 
pounds  and  being  less  bulky  than  a  typewriter. 

The  unit  for  the  reception  of  the  radio- 
telegraph communications  records  the  words  in 
code  just  as  they  were  sent.  However,  the 
message  is  mechanically  decoded  before  it  is 
actually  put  down  on  paper  by  the  receiving 
operator,  who  manipulates  a  keyboard  accord- 
ing to  the  letters  spelled  out  on  an  electrically- 
illuminated  alphabet-board  identical  in  ar- 
rangement with  his  keyboard.  For  the  sake 
of  convenience  in  transmission  and  as  an  extra 
precaution  for  insuring  secrecy,  the  sending 
mechanism  automatically  prints  the  code  in 
groups  of  five  letters,  and  the  decoding  unit,  at 
the  wireless  receiving  station,  converts  these 
five-letter  groups  back  into  understandable 
English  words. 

The  operator  of  the  code  receiving  unit  main- 
tains on  a  rack  in  front  of  him  a  number  of 
these  spools  or  code  wheels  which  correspond 
in  wiring  to  similar  wheels  at  the  transmitting 
point.  The  operator  who  is  to  decode  the 
message  needs  to  know  on  which  key  letter  the 
opposite  wheel  was  set  in  order  that  he  may 
set  his  wheel  at  the  same  key  letter  to  start 
decoding.  This  is  necessary  since  a  wheel  set 
at  any  one  of  the  twenty-six  key  letters  causes 


A  Radio  Code  with  Eleven  Million  Variations 


63 


the  machine  to  write  an  entirely  different  code. 
Therefore,  it  is  important  either  to  print  the 
key  letter  on  which  a  code  wheel  starts  coding 
as  the  first  letter  of  the  message,  or  to  have  it 
understood  in  advance  what  key  letter  will  be 
used.  Differently  expressed,  letters  common 
to  two  wheels  are  first  sent,  which  affords  a 
"key"  to  the  receiving  operator  to  insert  into 
his  machine  the  similarly  electrically-wired 
code  wheel  from  his  rack.  That  is,  only  two 
wheels  that  have  electric  wiring  in  common  will 
function  together. 

The  so-called  "  Hebern  Electric-Super  Code," 
to  quote  the  inventor,  "is  merely  the  applica- 
tion of  the  electric  current  in  certain  combina- 
tions, which  causes  the  machine  at  the  receiv- 
ing end  to  reproduce  in  understandable  words 
an  apparently  meaningless,  yet  systematic, 
jumble  of  words  sent  out  by  the  operator  of 
the  sending  machine.  Neither  the  sending  nor 
the  receiving  operator  knows  the  letters  that 
are  going  through  the  air;  that  is  the  secret 
of  the  machine,  or  rather  the  secret  of  the  two 
little,  electrically  synchronized  wheels,  a  dozen 
of  which  can  be  carried  in  a 
man's  coat  pocket.  The 
machine  without  the  wheel 
is  useless;  the  wheel  without 
the  machine  is  nothing  but 
a  little  metal  bobbin. 

"To  solve  any  one  mes- 
sage sent  out  between  any 
two  of  these  machines  and 
plucked  from  the  air  by 
wireless  instruments,  would 
require  exactly  11,881,376 
experiments,  and  it  would 
require  all  the  time  of  a 
staff  of  code  experts  for 
100  years  to  make  these  ex- 
periments." 

The  "Hebern  Electric- 
Super  Code"  is  built  in  two 
units,  one  design  being  ap- 
plicable to  the  service  of  the 
United  States  Government 
in  times  of  war  or  peace, 
and  the  other  provided  with 
a  typewriter  and  adaptable 
to  commercial  purposes.  It 
is  understood  that  the  in- 
ventor will  not  sell  these 
machines,  but  will  lease 
them  to  interested  parties. 
The  machine   is  only 


about  8  by  10  inches  in  dimensions  and  may 
be  carried  from  place  to  place  in  a  small 
case. 

The  protection  of  documents  issued  by  banks, 
such  as  travelers'  checks,  drafts,  cashiers' 
checks;  the  transmission  of  important  business 
papers  between  banks  or  other  commercial 
firms,  and  as  a  means  of  preventing  forgery,  are 
among  the  suggestions  advanced  for  the 
application  of  this  wonder-working  mechanism 
to  peace  times.  Somebody  has  stated  that 
code  messages  sent  during  the  Civil  War  have 
not  yet  been  deciphered.  Even  as  late  as 
the  World  War  the  imperfection  of  code  sys- 
tems was  realized  when  during  the  naval  en- 
gagement off  Jutland  the  code  system  was 
abandoned  after  a  trial  of  one  hour  and  mes- 
sages received  during  that  brief  sixty  minutes 
were  not  deciphered  for  days  thereafter.  The 
use  of  radio  and  the  invention  here  described 
may  solve  the  problem  of  the  United  States 
in  the  event  of  future  wars,  when  a  secret  and 
yet  readily  understandable  code  system  is  a 
pressing  need. 


S 


i)  Q)  viJ  \§)  (4)  C2)  mD' 

THE  HEBERN   ELECTRIC-SUPER  CODE  MACHINE 


Among  the  "Hams" 


OFFICERS  AND  MEMBERS  OF  THE  MILWAUKEE  AMATEURS*  RADIO  CLUB 
Beer  may  have  put  Milwaukee  on  the  map,  but  this  organization  is  doing  its  best  to  keep  it  there.  Founded  in  1917,  the 
Club  has  had  a  steady  growth,  and  its  "ham-fest",  technical  lectures,  spirited  debates,  and  operating  activities  have 
evidenced  a  high  degree  of  interest  and  enthusiasm  among  the  forty-odd  members,  Meetings  are  held  weekly,  at  which 
visitors  and  prospective  members  are  welcome,  and  the  Club  is  always  ready  to  help  the  newcomer  by  teaching  him  the 
code  and  enlarging  his  acquaintance  among  radio  amateurs 


AMATEURS  TAKING  THE  CODE  TEST  AT  THE  HOTEL  PENNSYLVANIA,  NEW  YORK 
This  receiving  contest,  held  to  determine  the  fastest  operator  in  the 
Second  District,  is  an  important  feature  at  each  annual  convention 


All  Boy  Scouts,  Attention! 

RADIO  BROADCAST  announces  a  contest,  startine,  now  and  ending  July  31,  1023,  to  determine 
WHAT  BOY  SCOUT  TROOP  HAS  DONE  OR  IS  DOING  THE  MOST  WITH  RADIO. 


Prizes  for  Winning  Articles 

FIRST  PRIZE:    CROSLEY  MODEL  X  4-TUBE  RECEIVER. 

This  receiver,  which  may  he  used  with  dry-cell  tubes  if  desired,  consists  of  detector,  one  stage  of 
tuned  radio-frequency  and  two  stages  of  audio-frequency  amplification.  [Advertised  in  Radio 
Broadcast). 

SECOND  PRIZE:    MUSIC  MASTER  LOUD  SPEAKER. 

This  is  the  new  loud  speaker,  made  hy  the  General  Radio  Corporation.  {A  picture  and  description 
of  it  appear  in  the  advertising  pages  of 

THIRD    PRIZE:  THREE 

The  WD-11  is  the  well-known  dry- 
Corporation.    (Filament  voltage  1.5, 

A  YEAR'S  SUBSCRIPTION  TO 
given  as  prices  for  the  ten  next  best 

These  prices  will  be  awarded  to 
troop  may  delegate  one  of  its  members  to 


Rules  of 

/.  Articles  must  be  true  accoxmts  of  radio  with  relation  to  your  particular  troop:  what  you  have  done,  or  are 
doing,  or  both. 

2.  Every  article  must  be  written  by  a  Scout  or  by  more  than  one  Scout  belonging  to  one  troop. 

3.  Articles  should  be  between  500  and  1000  words  long. 

4.  Good  photographs  to  illustrate  the  article  will  count  50%  in  judging  contributions. 

5.  Typewritten  manuscript,  double-spaced,  is  desired,  though  not  required. 

6.  Address  contributions  to  Scoilt  Contest,  Radio  Broadcast,  Doubleday,  Page  2r  Company,  Garden  City,  N.  Y. 

Scouts  have  done  splendid  work  in  maintaining  communication  by  radio  in  time  of  floods  and  disaster,  in 
copying  and  spreading  the  market  reports  transmitted  by  the  government  Farm  Bureaus,  in  training  themselves 
along  mechanical  and  electrical  lines,  and,  in  short,  in  using  radio  as  a  part  of  scout  work  in  a  way  consistent 
with  the  best  traditions  of  scouting.  What  have  you  to  tell  of  your  troop' s  past  or  present  activities?  Get  your 
scribes  and  photographers  under  way  with  that  story  which  will  put  in  a  strong  bid  for  first  pri^e.  How  would 
a  receiver  with  three  stages  of  amplification  go  in  your  troop? 

Beginning  with  the  July  number  of  Radio  Broadcast,  the  best  articles  will  be  published.  The  winners 
will  be  announced  in  the  September  number,  and  unless  the  three  best  articles  have  been  previously  published, 
they  will  appear  in  that  issue. 


Wanted — Information  on  Railroad  Radio 

The  Committee  on  Application  of  Radio  to  Moving  Trains  of  the  Association  of  Railway 
Electrical  Engineers  desires  to  communicate  with  any  one  who  can  give  information  regarding 
actual  experiments  in  radio  reception  or  transmission  to  or  from  a  moving  train. 

Kindly  communicate  with  the  Chairman  of  the  Committee, 

Mr.  P.  S.  Westcott, 

Assistant  Car-Lighting  Engineer, 

Chicago,  Milwaukee  &  St.  Paul  Ry.  Company, 

West  Milwaukee  Shops,  Milwaukee,  Wisconsin 


Radio  Broadcast). 

WD-11  VACUUM  TUBES. 

cell  tube  manufactured  for  the  Radio 
plate  voltage  22^/2 — 45). 

"RADIO  BROADCAST"  will  be 
contributions  in  this  contest. 

troops,  not  to  individuals,  although  any 
prepare  the  story. 


the  Contest 


Why  Life  is  Interesting  to  a 
Commercial  Operator 

Amusement,  Experience  and  Education  Come  in  Daily  Doses  to  the  Sea-Going 
Radioist,  as  this  True  Story  of  Three  Trips  on  a  Passenger  Vessel  Discloses 

By  A.  HENRY 


CAN  you  imagine  being  eighteen 
years  old  and  having  sailed  as 
Chief  Radio  Operator  and  sending 
out  an  SOS  and  being  rescued 
and  written  up  in  your  home- 
town paper  without  noticing  that  the  size  of 
your  hat  was  entirely  too  small?  If  you  can't 
you  will  never  appreciate  my  feelings  for  the 
week  following  my  re- 
turn from  my  first  trip 
to  sea.  If,  on  the 
other  hand,  you  can 
imagine  the  self-suffi- 
ciency such  a  series 
of  events  is  likely  to 
leave  in  their  wake, 
you  can  understand 
my  air  castles. 

And  what  is  more, 
my  pockets  were  well 
lined  with  real  shekels 
and  it  was  anything 
but  difficult  to  engage 
the  company  of  ladies 
fair,  who,  but  a  short 
month  before  would 
have  refused  my  invitations  with  alacrity  if  not 
disdain.  Few  among  them  can  resist  the 
possibilities  of  association  with  a  front  page 
head-liner.  Probably  because  news  in  our 
town  was  scarce  at  the  time,  much  space  was 
devoted  to  somewhat  extravagant  stories  of  my 
heroic  deeds  upon  the  sea.  Because  there 
was  really  nothing  much  for  me  to  tell  reporters, 
they  spun  great  yarns  about  modesty  in  the 
usual  way.  But,  you  may  wonder  why  you 
are  told  of  these  vejry  natural  and  uninteresting 
details,  and  my  only  excuse  is  that  I  would  like 
you  to  have  some  faint  idea  of  my  feelings  upon 
being  called  upon  the  carpet  in  the  holy  of 
holies  over  which  the  Superintendent  presided. 
You  see,  a  week  of  pampering  had  almost  com- 
pletely altered  my  viewpoint  of  life  and  the 
satisfaction  of  being  the  centre  of  attraction 


Life  on  the  Ocean  Wave 

This  is  the  third  of  a  series  of  articles  dealing 
with  Radio  Operating  As  a  Career.  The  first 
article  of  the  series  appeared  in  our  March 
number. 

These  stories  are  true  and  are  actually  chap- 
ters from  the  life  of  the  author  himself,  who 
has  been  through  the  mill. 

Next  month,  Mr.  Henry  is  going  to  tell  of 
his  experiences  on  a  private  yacht  which  kept 
him  in  Mexico  for  five  months.  Among  other 
interesting  incidents  he  describes  an  attack 
upon  the  yacht  by  Mexicans,  who  attempted 
to  put  the  radio  equipment  out  of  business  by 
doing  away  with  the  operator. — The  Editor. 


in  a  small  town  was  an  entirely  new  and  not 
unpleasant  sensation. 

1  was  waiting  in  the  "static  room",  which,  a' 
few  years  ago,  was  the  ante-chamber  to  the 
offices  of  the  Marconi  Wireless  Telegraph 
Company  of  America,  where  incoming  and  out- 
going radio  men  gathered  and  swapped  stories 
of  true  and  imaginary  escapades  in  foreign 

lands,  while  waiting  a 
summons  to  appear 
before  the  Superinten- 
dent for  assignment, 
re-assignment,  or — 
the  "gate."  Just 
above  the  door  leading 
into  that  gentleman's 
private  office  a  buzzer 
hung  from  a  screw, 
and  it  was  connected 
by  a  wire  system  run- 
ning into  the  "Su- 
per's"  office,  the  repair 
department  and  the 
radio  instructor's 
office.  The  gentry  in 
charge  of  affairs  found 
this  means  of  communicating  between  their 
offices  quite  valuable;  and  the  buzzer  also 
served  to  call  the  desired  operators  to  the  desk 
of  the  "  Super." 

Even  the  older  operators  who  gathered  in 
this  ante-chamber  had  accepted  me  into  their 
midst,  for  in  order  to  impress  them,  I  had  told 
a  rather  laudatory  story  of  my  shipwreck 
experience  in  a  casual  manner  designed  to 
conceal  the  exaggeration.  As  one  operator  who 
had  just  returned  from  Yucatan  and  Vera  Cruz 
on  the  Esperanto.,  of  the  Ward  Line,  finished 
a  tale  concerning  the  embarrassing  situations 
he  encountered  in  attempting  a  courtship 
with  a  lady  whose  language  he  could  not  savvy 
and  the  mirth  of  his  auditors  was  reaching  a 
climax,  the  buzzer  above  the  door  grunted  the 
symbols  which  spelled  my  name  and  with  a 


68 


Radio  Broadcast 


knowing  wink  I  left  the  group  and  went  into 
the  office. 

On  reaching  a  point  just  in  front  of  the  boss's 
desk,  I  stopped  and  maintained  a  respectful 
silence  until  he  had  finished  the  very  serious 
and  laborious  task  of  affixing  his  signature  to  a 
letter.  Without  looking  up  he  proceeded  to 
talk  to  me  and  read  over  another  letter  simul- 
taneously. At  least  here  was  a  man  who  was 
not  very  much  concerned  with  my  heroic 
exploit  of  a  few  weeks  ago,  and  if  his  attitude 
was  a  little  disconcerting,  his  remarks 
were  even  more  so. 

"  Henry,"  he  said,  "you  are  to  be 
promoted — ".  Following  a  slight 
pause,  he  looked  up  and  a  partial 
smile  crossed  his  face,  but  he  became 
serious  and  most  matter-of-fact  as 
he  proceeded.  "Yes,  we're  satisfied 
with  your  work  and  I'm  going  to  as- 
sign you  to  a  passenger  vessel.  You 
are  to  sail  the  day  after  to-morrow  at  three. 
Here's  your  assignment." 

I  was  greatly  pleased  and  said  so  and  was 
about  to  withdraw  when  he  cleared  his  throat 
and,  after  a  certain  amount  of  hemming  and 
hawing,  told  me  that  my  promotion  was  from  a 
tug  to  a  passenger  vessel  but  my  short  time  in 
the  company's  service  did  not  warrant  an 
increase  in  salary.  Further  explanation  dis- 
closed the  fact  that  my  youth  would  not  permit 
my  assignment  as  chief  operator,  but  my  salary 
would  stand  without  reduction  despite  my 
sailing  as  junior.  By  the  time  he  had  finished 
I  knew  that  he  had  outgeneralled  me  in  a  very 
thorough  manner  and  I  made  a  rather  em- 
barrassed departure.  Since  then  I  have  often 
wondered  why  that  suave  gentleman  wasted  his 
time  in  a  position  such  as  his,  when  he  could 
have  made  a  fortune  selling  oil  stock  or  gold 
bricks. 

At  any  rate  1  was  assigned  to  one  of  the 
Clyde  Line  steamers  which  plied  between  New 
York,  Charleston,  S.  C,  and  Jacksonville,  Fla. 
The  day  before  we  sailed  1  took  my  bags  over, 
handed  my  assignment  to  the  Chief  Officer  be- 
cause the  Captain  was 'not  aboard,  and  met  the 
chief  operator.  He  seemed  a  good  sort  but  he 
was  one  of  those  uncommunicative  fellows  who 
mind  their  own  business  and  show  no  desire 
to  have  any  but  strictly  business  relations  with 
subordinates.  He  proved  to  be  a  very  reason- 
able and  just  fellow — but  he  gave  me  a  pain. 
We  shared  an  inside  room  in  the  after  section  of 
the  saloon  deck  just  above  the  propeller  and 


hard  by  the  men's  wash-room.  Steamship 
companies  are  always  very  solicitous  for  the 
comfort  of  the  radio  men  that  way.  They 
know  that  the  vibration  is  a  sleep  producer  and 
that  it  is  very  interesting  and  entertaining  on 
rough  nights  to  hear  the  slamming  of  the  wash- 
room door  as  landlubbers  rush  from  their  bunks 
in  a  never  ending  procession. 

The  radio  shack  was  on  the  promenade  deck 
just  abaft  the  main  stack  and  directly  above 
the  galley.  We  never  suffered  from  the  cold, 
especially  when  we  got  below  Hat- 
teras  and  the  tropical  calms  settled 
upon  us.  We  were  saved  the  anxiety 
caused  by  not  knowing  what  to  ex- 
pect on  the  menu,  for  the  appetizing 
aroma  of  onion  soup  and  similar 
delicacies  was  ever  present  in  our 
little  cabin. 

Radio  shacks  are  not  large  as  a 
rule — ours  was  particularly  small  and 
must  have  been  laid  out  by  a  past  master  at 
space  conservation.  There  was  a  place  for 
everything  and  one  thing  out  of  its  place 
crowded  the  room  beyond  comprehension. 

In  addition  to  the  radio  equipment  there  was 
a  typewriter  and  a  multigraphing  machine, 
used  to  prepare  the  radio  news  section  of  the 
little  magazine  we  sold  each  day.  And  my 
chief  ,  who  happened  to  be  a  camera  fiend,  had  a 
goodly  store  of  film,  printing  paper,  various 
chemicals  in  powder  and  liquid  form,  a  red 
lantern  and  the  usual  coterie  of  trays,  paper 
clips,  etc.  There  was  hardly  room  for  us  to  sit 
down  in  comfort.  There  was  no  room  at  all 
for  the  radio  equipment  I  brought  along,  so  I 
made  no  reference  to  it,  although  I  knew  it 
would  have  improved  the  outfit  greatly. 

On  sailing  day  I  found  a  vantage  point  in  the 
vicinity  of  the  gang-plank  and  was  agreeably 
surprised  to  note  the  number  of  attractive 
young  ladies  who  made  their  way  aboard.  A 
feeling  of  superiority  pervaded  me  and  I  paced 
the  deck  like  a  pouter  pigeon,  in  an  effort  to 
engage  the  attention  of  some  of  the  attractive 
maidens,  but  none  of  them  seemed  to  heed  me 
in  the  least,  for  how  were  they  to  know  that  I 
held  the  important  post  of  Junior  Radio  Officer? 
I  had  no  uniform  and  must  have  appeared  to  be 
one  of  those  individuals  who  imagines  that  he 
is  entirely  sea-broken  after  a  ferryboat  ride 
or  a  sail  in  some  yacht  belonging  to  a  friend 
twice  removed. 

Some  of  the  ladies  strolled  about  the  deck 
and  I  went  into  the  radio  shack  and  acted  as  I 


Why  Life  Is  Interesting  to  a  Commercial  Operator 


69 


HARDLY  IN  KEEPIN 

Was  my  job  of  h 


thought  a  sophisticated 
operator  would  act.  For 
the  benefit  of  several  gen- 
tlemen who  made  it  their 
business  to  stop  at  my 
door  and  ask  questions,  I 
unsheathed  a  bundle  of 
technical  terms,  designed 
to  fill  them  with  awe,  but 
when  one  of  the  group 
asked  some  questions  that 
indicated  quite  plainly 
that  his  knowledge  of  radio 
was  greater  than  my  own, 
I  recalled  an  important 
engagement  elsewhere  and 
closed  shop  to  visit  our 
sleeping  quarters. 

Here  I  found  my  chief 
laying  out  his  uniform  on 
my  bunk  and  making 
ready  to  try  a  little  slum- 
ber in  his  own.  Assured 
that  he  would  not  bother 
me  for  a  while  I  made 
my  way  back  to  the 
operating  room,  swung  the  door  wide  open, 
removed  my  coat  and  started  the  motor- 
generator.  I  ts  hum  attracted  a  few  people,  so  1 
disconnected  the  aerial  lead  and  began  manipu- 
lating the  key  while  the  heavy  spark  boomed  in 
its  chamber.  A  crowd  soon  gathered  outside 
the  door,  though  I  pretended  to  pay  no  at- 
tention. I  made  various  adjustments  and 
exercised  all  the  meters,  shut  down  the  set  and 
turned  around  to  answer  any  questions  which 
might  be  forthcoming. 

A  young  lady,  evidently  with  her  mother, 
beamed  upon  me  and  asked  about  the  wonders 
of  wireless.  She  was  most  attractive  and  we 
chatted  for  some  time  and  became  quite 
friendly,  though  we  had  not  reached  the  point 
where  an  exchange  of  names  takes  place.  Here, 
indeed,  was  a  stroke  of  rare  luck.  1  made  use 
of  every  device  I  could  recall  learning  from  the 
old-timers  in  the  static  room  and  my  progress 
was  so  satisfactory  that  I  was  wondering  how 
best  to  invite  her  to  visit  the  shack  occasionally 
on  the  trip  south. 

Suddenly  there  was  a  blood-curdling  racket 
on  the  deck  and  it  seemed  to  be  coming  in  our 
direction.  A  colored  porter  bawled  "All 
Ashore's  Goin'  Ashore"  and  accompanied 
himself  by  lambasting  a  metal  tom-tom.  My 
visitors  dispersed  and  the  attractive  young 


G  WITH  MY  AUGUST  POSITION  AS  RADIO  OFFICER 

awking  the  magazih.es  we  printed,  at  a  dime  a  copy 

lady  thanked  me  for  my  kindness  and  departed. 
I  took  a  position  near  the  gang-plank  and  by 
the  time  that  porter  finished  his  parade  most 
of  the  attractive  ladies  had  made  their  way 
down  the  gang-plank  and  were  waving  tear- 
bedewed  handkerchiefs  to  departing  mothers, 
fathers,  etc.  Most  of  those  remaining  aboard 
seemed  to  be  possessed  of  husbands  and  as  we 
pulled  out  into  the  stream  I  resigned  myself  to 
my  work  and  tried  to  forget  the  alluring  possi- 
bilities of  feminine  companionship  which  had 
loomed  up  during  the  past  hour. 

As  we  left  the  dock  I  reported  to  the  Sea 
Gate  Station  and  was  advised  that  there  were 
no  messages  on  hand  for  me,  so  I  strolled 
around  the  deck  a  few  times,  stopping  here  and 
there  to  have  a  chat  with  the  passengers.  A 
group  of  young  folks  attracted  my  attention 
and  I  spent  some  little  while  discussing  all 
manner  of  important  events  such  as  the  time 
made  in  races  at  a  college  athletic  meet  and  the 
possibility  of  bad  weather  after  passing  Scot- 
land Lightship. 

We  sailed  at  three  and  it  was  not  long  before 
dinner  time  rolled  around.  My  chief  relieved 
me  and  1  found  my  way  into  the  main  dining 
saloon,  where  some  of  the  passengers  had  already 
gathered,  and  a  rattle  of  dishes  in  the  pantry 
proclaimed  that  service  had  started.    A  Negro 


7o 


Radio  Broadcast 


THE  RADIO  MAN  S  DINNER  TABLE  IS  LIKELY  TO  BE  GRACED  BY  A  COSMOPOLITAN  GROUP 
Consisting  of  a  spoiled  society  bud,  the  heavily  bejeweled  wife  of  a  newly  '  arrived"  pawn-broker,  an  English  remittance 
man,  and  a  lady  who  is  "well-known  in  society."    Often  the  peace  of  mind  of  everyone  present  is  upset  by  the  ill-bred 
youngster  whose  mother  is  more  attentive  to  the  men  aboard  than  to  her  child 


waiter  whose  smile  disclosed  two  lines  of  ivory 
and  gold  ushered  me  to  a  seat,  which  was 
reserved  for  me.  It  was  at  a  table  some  little 
distance  from  the  Captain's,  so  1  felt  quite  at 
home. 

It  is  unlikely  that  any  place  in  the  world, 
even  a  railroad  station,  permits  the  study  of  so 
many  different  kinds  of  people  as  a  steamship. 
One  finds  gentlemen  who  can  eat  peas  only  if 
served  with  mashed  potatoes  and  who  imagine 
that  their  discourses  upon  the  latest  scientific 
discoveries  are  amazingly  interesting  to  their 
co-voyagers.  One  is  likely  as  not  to  find 
at  his  table  the  wife  of  a  newly '"  arrived " 
pawnbroker,  heavily  bejewelled  and  master 
of  gestures  accompanied  by  knife  and  fork; 
an  English  "remittance  man"  on  his  way 
to  parts  unknown;  a  society  matron,  whose 
dwindling  fortune  makes  it  increasingly  diffi- 
cult for  her  to  keep  up  the  pace  her  posi- 
tion demands,  while  very  much  in  evidence 
is  one  of  those  ill-bred  youngsters  who  delights 


in  spilling  soup  without  regard  to  the  direction 
it  takes  by  yanking  the  table-cloth  in  a  hair- 
raising  fashion. 

Following  the  evening  meal  among  just  such 
company  1  was  to  relieve  my  chief  while  he  ate 
his  dinner  and,  following  that,  I  would  retire 
until  one  o'clock  the  next  morning.  From  one 
to  eight  was  my  section  of  the  night  watch  and 
there  was  quite  a  bit  of  work  to  be  attended  to. 
Among  other  things  it  was  necessary  to  print 
the  radio  section  for  the  magazine  we  sold. 
The  Chief  copied  the  press  reports  from  one 
of  the  coast  stations  and  typed  them  while  he 
was  on  duty.  Our  typewriter  was  provided 
with  a  duplicating  ribbon,  so  it  was  but  neces- 
sary for  me  to  put  the  original  in  a  duplicating 
machine  and  draw  off  as  many  copies  as  we 
estimated  could  be  sold. 

If  there  was  any  brass  to  shine  or  similar 
work  to  be  done,  the  night  watch  was  the  time 
to  do  it,  for  it  was  difficult  to  remain  awake. 
The  monotony,  however,  could  be  broken  by 


Why  Life  Is  Interesting  to  a  Commercial  Operator 


7' 


an  occasional  trip  to  the  officers'  mess  where 
coffee  and  stale  sandwiches  could  be  found. 

In  the  morning  the  chief  had  his  breakfast 
and  then  relieved  me.    When  my  breakfast 
v/as  finished  I  took  an  armful  of  magazines  and 
hawked  them  about  the  deck  at  a  dime  a  copy. 
Being  associate  editor,  reporter,  printer  and 
newsboy  was  interesting  but  it  was  hardly  in 
keeping  with  the  august  position  of  the  Radio 
Officer,  and  I  began  to  cast  about  for  a  better 
selling  system.    By  appointing  young  ladies 
to  the  positions  of  reporter,  subscrip- 
tion and  circulation  manager,  society 
reporter,  etc.,  we  were  able  to  sell  yggjjg 
more  copies  with  less  effort  and  still  /mbm^ 
maintain  our  dignity.    Thus,  instead  [l|l§§jl 
1  if  retiring  at  ten-thirty  or  eleven,  \|m|1( 
it  was  possible  for  me  to  get  to  bed     \""  ^ 
by  nine  or  nine-thirty,  though  by  that 
hour  the  extreme  desire  for  sleep 
usually  had  passed  and  the  few  winks  before 
lunch  time  amounted  to  little  or  nothing. 

After  we  had  been  out  two  days  on  my  first 
trip  on  this  vessel,  I  happened  to  be  in  the 
lounge  one  afternoon,  chatting  with  one  of  the 
"society  editors,"  who  was  a  very  comely  girl 
of  some  eighteen  or  twenty  years.  1  was  assist- 
ing her  to  dispose  of  a  box  of  chocolates,  when 
the  Captain  came  in.  Seeing  us,  he  smiled  and 
sat  down  with  us,  helping  himself  to  the  choco- 
lates. Most  of  his  remarks  were  addressed  to 
the  lady  and  he  seemed  to  be  enjoying  himself 
quite  well.  As  he  was  about  to  withdraw  he 
invited  us — I  was  included  by  a  half-hearted 
attempt  at  politeness — to  visit  the  pilot  house 
wherewe  could  see  the  navigating  instruments. 
He  asked  me  if  I  was  bound  for  Charleston  or 
Jacksonville,  and  seemed  somewhat  nonplussed 
at  my  reply  that  I  was  going  to  both  places  and 
then  back  to  New  York.  Somehow  or  another 
the  subject  of  wireless  was  brought  up  and  he 
passed  some  disparaging  remarks  about  the  sys- 
tem in  general  and  operators  in  particular. 

"Well,  Captain,"  said  the  pretty  society 
editor,  "this  young  man  must  be  somewhat 
different  from  most  operators  and  I  know  you 
must  like  him." 

"What's  he  got  to  do  with  it?" 

And  he  had  no  sooner  asked  the  question 
than  his  face  began  to  go  through  a  series  of 
contortions  as  it  dawned  upon  him  that  I  was 
his  junior  operator.  He  departed  before  his 
wrath  escaped,  but  it  was  not  more  than  a  few 
minutes  later  that  a  quartermaster  told  me  of 
the  Captain's  desire  to  see  me  in  his  cabin. 


Followed  a  lecture  about  ship's  discipline  dur- 
ing which  it  became  very  clear  to  me  that  none 
of  my  duties  included  the  entertainment  of  the 
lady  passengers — that  task  seemed  to  have 
been  meted  out  exclusively  to  the  Captain. 
Among  other  things,  it  was  essential  that  I 
procure  a  uniform  at  once  in  order  that  the 
Captain  might  not  again  mistake  me  for  a 
passenger  and  become  the  least  bit  friendly. 
Finally,  my  Chief  was  informed  of  my  trans- 
gressions and  advised  to  put  my  case  in  the 
hands  of  the  superintendent  upon  our 
return  to  New  York.    Captains,  as  a 
B|j^      rule,  are  strange  that  way.    In  their 
pT^sA    own  opinion  they  are  past  masters  at 
IJkH    entertaining  the  ladies;  but  a  radio 
gppPjl/    shack  has  wonderfully  romantic  pos- 
§|^=ir     sibilities  if  properly  engineered. 

In  this  particular  instance  the  "old 
man"  made  the  mistake  of  inviting 
the  young  lady  and  her  mother  to  lunch  with 
him  in  his  cabin  and  during  the  luncheon 
pointed  out  the  folly  of  having  anything  to  do 
with  wireless  operators.  From  his  description, 
we  were  a  bad  lot  and  no  fit  company  for  young 
ladies.  The  result  was  that  he  finished  his 
luncheon  alone  and  we  had  a  word  for  word 
report  of  the  proceedings,  which  the  ladies  be- 
lieved would  make  most  interesting  reading 
in  our  paper.  That,  of  course,  was  out  of  the 
question. 

Nothing  of  great  moment  happened  before 
we  arrived  at  Charleston,  where  my  Chief  took 
me  in  tow  to  point  out  the  places  of  historic 
interest.  A  classmate  of  mine,  who  was  on  his 
way  to  Miami  with  his  mother,  came  aboard 
and  there  was  another  lady  in  his  party.  As 
soon  as  we  left  the  dock  he  brought  her  around 
to  the  radio  shack  and  they  had  all  sorts  of 
good  things  to  eat  with  them.  A  few  minutes 
later  our  society  editor  arrived  upon  the  scene 
and  we  had  a  very  jolly  little  party. 

It  was  but  a  step  to  the  smoking  room  and  we 
could  have  all  sorts  of  pop.  There  were  pickles 
and  olives  and  ham  and  saltines  and  raspberry 
soda  and  the  usual  accessories  for  a  college 
girl's  dormitory  escapade.  Four  of  us  were 
inside  the  room,  one  seated  on  the  table;  one 
on  top  of  the  tuner;  one  in  the  only  chair  and 
one  on  the  door  sill.  Papers  containing  various 
edibles  were  strewn  about  wherever  they  could 
be  pushed  out  of  the  way.  One  of  the  girls 
had  a  harmonica  and  she  played  some  popular 
airs  while  we  all  sang  or  whistled  or  hummed. 
I  was  "on  watch"  and  therefore  could  not 


72 


Radio  Broadcast 


remove  the  headphones  and  dancing  was  out  of 
the  question  in  our  little  shack. 

We  had  just  finished  the  refrain  of  a  popular 
musical  number,  executed  with  great  gusto  and 
stamping  of  feet,  and  were  making  another 
attack  upon  the  food  when  the  room  was 
suddenly  darkened.  1  lowered  the  pop  bottle 
and  was  more  than  delighted  to  see  the  jolly 
old  Captain  standing  in  the  doorway.  He 
was  delighted,  too,  for  it  seems  that  our  singing 
had  reached  him,  while  he  vainly  sought  slum- 
ber. 

My  guests  were  dispersed  and  the  wrath  of 
the  master  again  descended  upon  my  unholy 
head.  I  was  a  young  fool — a  pest — an  in- 
subordinate jackass — and  a  few  other  things 
uttered  in  sub-audible  tones. 

Next  day  we  arrived  in  Jacksonville  and  my 
newly  made  friends  kindly  invited  me  to  visit 
them,  which  I  felt  at  perfect  liberty  to  do. 
There  were  no  "watches"  to  stand  and  I  did 


IT   WAS   AT    LEAST   A  UNIFORM 


not  put  in  my  appearance  aboard  ship  until  a 
few  hours  before  sailing.  I  had  met  the  Cap- 
tain, however,  in  the  dining  room  of  the  Wind- 
sor Hotel  and  though  he  said  nothing,  he  gave 
me  a  wicked  look. 

You  see,  one  of  the  officers  mentioned  that  the 
captain  was  a  regular  guest  at  the  Windsor 
by  courtesy  of  the  management.  Tales  had 
been  spun  in  the  static  room  of  similar  arrange- 
ments extended  to  radio  men  in  other  ports. 
After  a  certain  amount  of  argument,  it  was 
possible  to  convince  the  manager  that  we  could 
direct  a  great  number  of  guests  to  his  establish- 
ment in  return  for  a  room  with  bath.  This 
was  indeed  an  achievement  and  a  certain 
satisfaction  was  felt  when  we  could  ask  corres- 
pondents to  write  us  in  care  of  the  hotel. 
Well  do  1  remember  how  astonished  some  of 
the  passengers  would  be  to  find  that  we  lived 
in  a  hotel  while  ashore.  And  the  letters 
written  on  the  hotel  stationery  sent  to  friends 
at  home  were  designed  to  create  an  impression 
of  progress  in  the  world  of  commerce. 

Upon  arriving  in  New  York,  I  felt  rather 
doubtful  about  putting  in  an  appearance  at  the 
office,  but  funds  were  not  running  very  high 
and  a  few  dollars  would  relieve  some  of  the 
strain,  so  1  fared  forth.  Quite  to  my  surprise 
the  Senior  had  turned  in  a  favorable  report 
with  the  single  exception  that  the  Captain 
objected  to  my  sailing  again  without  a  uniform. 

For  the  next  three  days  I  spent  most  of  my 
spare  time  searching  for  a  uniform  at  my  price, 
but  it  was  not  to  be  had  and  the  Superintendent 
was  satisfied  to  have  me  make  another  trip 
provided  1  purchased  a  uniform  cap.  This 
1  did,  but  the  Captain  was  less  easily  satisfied 
and  insisted  that  I  could  not  leave  on  the  third 
trip  ununiformed,  so  once  again  my  time  in 
New  York  was  spent  hunting  for  proper  rai- 
ment. 

Eventually  1  was  able  to  procure  a  suit  from 
the  Superintendent  himself,  who  had  under- 
taken to  dispose  of  it  for  another  operator. 
After  he  had  seen  to  it  that  my  shekels  were 
delivered  safely  into  his  hand  he  informed 
me  that  the  fellow  who  had  previously  owned 
the  outfit  had  joined  the  angels  following  a 
contagious  disease,  but  he  assured  me  that  the 
perfect  fumigation  through  which  the  suit  had 
passed  made  it  quite  unlikely  that  1  would 
go  and  do  likewise. 


Broadcast  Receiving  Contest! 


Any  Number  of  Tubes — Any  Kind  of  Receiver 

THE  LONG-DISTANCE  RECEIVING  CONTEST,  to  determine  who  has  done  the  best  with 
ANY  NUMBER  OF  TUBES  AND  ANY  TYPE  OF  RECEIVER,  is  well  under  way.  The 
drawbridge  will  be  hauled  up  at  sunset  on  May  31st,  however,  and  after  that  even  the  most  imposing- 
looking  contributions  will  have  to  be  left  outside  the  portcullis.  A  great  many  of  them  will  probably 
gallop  through  in  a  cloud  of  dust  at  the  last  minute — but  that  is  dangerous  business,  and  we  advise 
you  not  to  try  it.    Read  through  the  Eight  Commandments  below,  roll  up  your  sleeves,  and  go  to  it. 

The  Four  Prizes 

First  Prize:  DE  FOREST  D-7  REFLEX  LOOP  RECEIVER 
This  receiver,  described  in  RADIO  BROADCAST  for  February  (page  297),  is  the  latest  product 
of  the  De  Forest  Company:  it  makes  three  amplifying  tubes  and  a  crystal  detector  do  the  work  of  six 
tubes.  The  loop  antenna  aids  in  selectivity  because  of  its  directional  properties.  An  ordinary  antenna 
and  ground  may  be  used,  however,  if  desired.  Recently,  a  man  in  Brooklyn,  N .  Y .  heard  a  broadcast- 
ing station  in  Seattle,  Wash.,  with  one  of  these  sets. 

Second  Prize:- GREBE  TUNED  RADIO-FREQUENCY  AMPLIFIER,  TYPE  "RORN" 
Illustrated  on  page  352,  RADIO  BROADCAST  for  February.    This  amplifier,  which  has  a 
wavelength  range  of  from  130  to  3000  meters,  may  be  used  with  any  form  of  home-made  or  bought 
receiver.    It  is  the  most  recent  development  of  a  company  widely  known  for  the  excellence  in  design  and 
workmanship  of  its  products. 

Third  Prize:  Choice  of 

THREE  OF  THE  NEW  RADIOTRON  UV-201-A  AMPLIFIER  TUBES  (6  volts,  £  of  an 
ampere),  or 

THREE  AERIOTRON  WD-11  DRY  CELL  TUBES  (i\  volts,  \  of  an  ampere). 
Fourth  Prize:  TIMMONS  LOUD-SPEAKER  UNIT 

This  unit,  which  may  be  connected  directly  to  the  output  of  your  amplifier,  has  a  diaphragm  ad- 
justable for  sounds  of  different  intensities,  and  when  used  with  two  stages  of  amplification  reproduces 
broadcasted  programs  about  as  loud  as  the  music  from  the  average  phonograph. 

Rules  of  the  Contest 

/.  You  should  list  all  broadcasting  stations  130  or  more  miles  away  from  the  receiving  point,  which 
you  have  heard  distinctly  (announcement  of  location  as  well  as  of  call  letters.) 

2.  Measure  distances  accurately,  and  give  aggregate  mileage.  (This  is  the  sum  of  all  the 
distances,  each  station  counted  once,  but  two  or  more  stations  in  the  same  city  being  counted  separ- 
ately.)   An  aggregate  mileage  of  less  than  1 3,000  miles  will  not  be  considered. 

3.  Manuscripts  should  include  the  following:  description  of  set,  directions  or  advice  for  con- 
structing and  operating  it;  any  "wrinkles"  or  makeshifts  which  you  have  used  to  advantage;  photo- 
graph of  your  apparatus;  circuit  diagram;  in  general,  anything  you  have  to  tell  that  will  make  your 
story  more  interesting  and  helpful.  Manuscripts  should  not  be  longer  than  2000  words.  Typewritten 
reports  preferred. 

4.  Data  should  be  arranged  in  three  columns,  under  the  headings:  call  letters,  location,  distance. 
3.    For  material  used,  a  liberal  rate  will  be  paid. 

6.  In  judging  contributions,  the  quality  and  interest  of  photographs,  text,  and  drawings,  and  the 
originality  and  general  effectiveness  of  the  apparatus  described,  will  have  greater  weight  than  the  list  of 
stations  heard,  although  a  long  list  of  distant  stations  will  distinctly  help. 

7.  The  Contest  begins  now  and  closes  May  31st,  1923. 

8.  Address:  Receiving  Contest,  RADIO  BROADC AST,  Doubleday,  Page&Co.,GardenCity,N  .Y. 


Six-Inch  Dry  Cells  and  WD-11  Tubes 


By  E.  E.  HORINE 

National  Carbon  Company,  Inc. 


F 


"^QR  more  than  twenty-five  years  the 
six-inch  dry  cell  has  been  a  popular 
source  of  small  amounts  of  electrical 
energy.  It  is  convenient,  compact, 
safe,  and  reliable.  It  is  in  such 
universal  demand  for 
a  wide  variety  of  pur- 
poses that  it  has  be- 
come a  staple  article  of 
commerce  all  over  the 
country.  It  may  be 
purchased  for  a  small 
sum  in  any  city,  town, 
or  village,  and  at  most 
country  cross  -  roads 
stores. 

With  such  a  cheap, 
convenient,  reliable 
source  of  energy  al- 
most universally  avail- 
able, it  is  natural  that 
designers  of  receiving 
vacuum  tubes  should 
bend  their  efforts  to- 
ward the  development 
of  a  tube  which  would 
be  so  economical  of  current  that  dry  cells  could 
be  used  for  heating  the  filaments. 

The  WD- 1 1  tube  is  the  first  among  these 
tubes  to  have  been  developed  and  placed 
on  the  market.  These  dry  cell  tubes  are  prov- 
ing popular,  and  deservedly  so,  for  they  are 
the  means  of  bringing  radio  to  rural  sections 
where  storage  battery  charging  is  a  real  prob- 
lem. They  also  have  a  strong  appeal  for  the 
city  dweller,  who,  although  surrounded  by  cheap 
current  and  storage  battery  charging  stations, 
welcomes  relief  from  the  relatively  large  in- 
vestment for  a  storage  battery  and  its  attend- 
ant bother.  Dry  battery  tubes  bid  fair  even- 
tually to  replace  all  storage  battery  receiving 
tubes;  so  a  study  of  the  characteristics  of  dry 
cells  is  of  particular  interest  to  the  radio  enthu- 
siast. 

The  dry  cell  is  inherently  an  intermittent 
service  cell.  That  is,  it  must  be  given  op- 
portunity to  recuperate  between  periods  of 
service  in  order  to  use  it  most  economically. 


Since  the  Westinghouse  Company  brought 
out  the  WD- 1 1  dry  cell  tube  its  use  has  be- 
come increasingly  popular.  There  is  no 
doubt  that  it  is  one  of  the  most  important 
forward  steps  made  in  receiving  apparatus 
during  the  past  few  years.  It  has  actually 
made  radio  a  source  of  pleasure,  information, 
and  instruction  for  many  who  would  never 
have  availed  themselves  of  it  otherwise. 

The  satisfaction  derived  from  a  receiver 
employing  one  or  more  of  these  tubes  depends 
in  no  small  measure  upon  a  suitable  filament 
current  supply.  With  this  in  mind  we  asked 
Mr.  E.  E.  Horine,  of  the  National  Carbon 
Company,  who  has  directed  a  great  deal  of 
research  work  in  the  application  of  dry  cells  to 
radio,  to  prepare  this  helpful  data  for  our 
readers  on  this  important  subject. — The 
Editor. 


More  work  can  be  obtained  from  a  dry  cell  by 
operating  it  intermittently  than  by  drawing 
current  from  it  continuously.  Practically  all 
radio  receiving  sets  are  operated  for  a  few 
hours  each  day,  standing  idle  the  rest  of  the 

time,  which  is  an  ideal 
arrangement  from  a 
dry  battery  stand- 
point. 

The  uses  to  which 
dry  cells  are  put  are  so 
numerous,  and  the  de- 
mands made  upon 
them  are  so  diversified, 
that  it  has  been  neces- 
sary to  develop  a  num- 
ber of  different  types 
of  cells,  each  especially 
suited  for  some  par- 
ticular class  of  service. 
In  addition  to  these 
so-called  "single- 
purpose"  cells,-  there 
has  also  been  de- 
veloped the  "general- 
purpose"  cell,  de- 
signed to  cover  a  number  of  uses.  This  latter 
is  the  cell  with  which  the  public  is  most  familiar, 
and  is  the  one  usually  sold  over  the  counter  to 
the  retail  trade.  It  is  generally  used  for  motor 
ignition,  bell  ringing,  annunciator  systems, 
and  lately  for  heating  the  filaments  of  vacuum 
tubes.  Our  discussion  of  dry  battery  charac- 
teristics refers  only  to  this  general-purpose 
battery. 

When  a  radio  enthusiast  purchases  a  number 
of  dry  cells  for  his  set,  all  he  wishes  to  know 
about  them  is  how  much  electrical  energy  he 
is  getting  for  his  money.  However,  he  does 
not  couch  his  inquiry  in  this  style:  he  merely 
asks  "How  long  will  they  last?"  This  is  a 
reasonable  and  proper  question,  and  on  the  face 
of  it,  a  simple  one.  Yet,  of  all  the  questions 
he  might  have  asked  about  dry  cells,  this  is 
perhaps  one  of  the  most  difficult  to  answer, 
the  main  reason  being  that  the  amount  of 
service,  measured  in  hours,  obtainable  from  a 
dry  cell,  depends  largely  on  the  unknown 


Six-Inch  Dry  Cells  and  WD-ii  Tubes 


75 


Water  Motor  — 
(Vvffrag  |.l  lbs. 

ftewre  for 
VSatis  factay  Operation 


FIG.  1 

factor  of  just  how  the  cell  is  to  be  used.  All 
the  manufacturer  can  do  is  to  see  to  it  that  his 
product  contains  the  maximum  amount  of 
electrical  energy  when  it  leaves  his  hands. 
There  his  control  over  the  cells  ceases,  and 
from  that  point  on,  the  amount  of  service 
obtainable  from  them  is  strictly  up  to  the 
user.  In  the  hands  of  different  people, 
identical  cells  will  deliver  widely  divergent 
amounts  of  service. 

If  the  exact  conditions  of  service  are  known, 
it  is  quite  easy  to  predict  just  how  many  hours 
of  useful  work  may  be  obtained  from  an  aver- 
age dry  cell.  But  conditions  of  service  vary, 
even  in  radio  work,  and  the  best  that  can  be 
done  is  to  state  how  many  hours  of  service 
should  be  obtained  under  certain  different 
conditions. 

In  many  ways,  a  dry  cell  may  be  compared 
to  a  tank  of  water.  In  Fig.  i  such  a  tank  is 
shown  connected  to  a  water  motor.  The  motor 
is  so  designed  that  it  will  not  work  if  the  water 
pressure  falls  below  i.i  pounds  per  square  inch. 
The  height  of  the  tank  is  such  that  the  resultant 
pressure  when  full  is  1.5  pounds  per  square 
inch.  To  control  the  pressure  applied  to  the 
motor,  a  valve  which  varies  the  resistance  to 
the  flow  of  water  is  inserted  in  the  line  between 
the  tank  and  the  motor. 

As  water  is  drawn  from  the  tank,  the  level 
of  water  falls,  and  the  pressure  drops.  After 
a  certain  definite  amount  of  water  has  been 
withdrawn,  the  pressure  reaches  1.1  pounds 
per  square  inch,  following  which  the  motor 
will  fail  to  function  due  to  lack  of  sufficient 
pressure.  If  the  operator  of  this  device  fails 
to  regulate  the  valve  properly,  so  that  at  times 
the  pressure  on  the  motor  is  in  excess  of  1.1 
pounds  per  square  inch,  the  water  will  be 
drained  out  of  the  tank  more  rapidly,  and  the 
length  of  service  down  to  the  final  1 . 1  pounds, 
will  be  materially  reduced. 

The  conditions  in  Fig.  2  are  the  same  as  in 


Fig.  1 ,  except  that  here  we  are  dealing  with  a 
flow  of  electrical  energy  instead  of  water.  The 
dry  cell  is  the  container  of  electrical  energy. 
This  energy  is  held  under  a  pressure  of  1 . 5  volts. 
The  proper  operating  pressure  for  the  WD-n 
tube  is  i.i  volts.  The  rheostat  serves  as  a 
voltage  regulator,  and  if  properly  manipulated, 
maintains  the  voltage  on  the  tube  constant 
at  i.i  volts. 

As  energy  is  drawn  from  the  cell,  the  voltage 
gradually  drops,  and  this  decrease  in  voltage 
must  be  compensated  for  by  adjusting  the 
rheostat.  Eventually  the  cell  voltage  falls 
to  i.i  volts,  after  which  satisfactory  operation 
will  not  be  obtained,  because  it  is  no  longer 
strong  enough  to  heat  the  tube  filament  to  a 
point  where  sufficient  electron  emission  occurs. 
The  lowest  voltage  at  which  a  dry  cell  can 
satisfactorily  supply  current  to  any  device  is 
called  the  cut-off  voltage.  This  figure  varies 
for  different  electrical  devices,  and  has  a 
marked  influence  on  the  amount  of  service 
obtainable  from  a  dry  cell. 

To  obtain  the  desired  characteristics,  the 
designers  of  the  WD-i  1  tube  found  it  advisable 
to  choose  i.i  volts  as  the  operating  voltage. 
This  means  a  cut-off  voltage  of  1.1  volts  for 
the  dry  cell  used  with  it. 

The  current  taken  by  the  WD-i  1  tube  at  1 . 1 
volts  is  about  one  quarter  ampere.  Curve  A, 
Fig.  3  shows  the  number  of  hours  of  service 
obtainable  from  a  six-inch  dry  cell,  delivering 
one  quarter  ampere,  two  hours  per  day,  to 
various  cut-off  voltages.  This  curve,  as  well 
as  others  presented  in  this  article,  is  the 
result  of  a  large  number  of  tests  on  several 
leading  makes  of  general-purpose  dry  cells, 
and  represents  the  average  performance  of  the 
various  makes,  rather  that  the  individual  per- 
formance of  any  one  make.  These  curves 
therefore  show  what  the  user  may  reasonably 


1.5  Volts -Initial 
1.1  Volts -Final 


Dry  Cell 


Voltage  Emulator 


FIG.  2 


WD -11  Tjbe 

&0>r,'ng  1.1  Volt! 

lot-  Satisfactory  Operation 


j6 


Radio  Broadcast 


1.20  MO  t.OO         Ceo         OSD         0.70         O.&O  O.50 


FIG.  3 

By  comparing  curves  A  and  B,  the  economy  of  using  two  dry 
cells  in  parallel  (curve  B)  for  each  tube  becomes  apparent 

expect  from  any  dry  cell  of  reliable  manufac- 
ture, provided  he  uses  it  properly. 

By  exhausting  the  cell  down  to  a  cut-off 
of  i .  i  volts,  at  the  rate  of  one  quarter  ampere, 
two  hours  per  day,  the  amount  of  service  obtain- 
able is  approximately  75  hours. 

Curve  B,  Fig.  3,  shows  the  amount  of  service 
obtainable  from  a  six-inch  dry  cell  when  de- 
livering one  eighth  ampere  two  hours  per  day. 
This  is  the  condition  prevailing  when  two  cells 
connected  in  multiple  (zinc  to  zinc  and  carbon 
to  carbon)  are  used  to  operate  one  WD-i  1  tube. 
Here  the  total  current  of  one  quarter  ampere 
is  divided  between  the  two  cells,  so  that  the 
discharge  from  each  is  one  eighth  ampere. 
Under  these  conditions,  the  amount  of  service 
obtainable  from  the  two  cells  is  approximately 
175  hours,  or  at  the  rate  of  87J  hours  per  cell, 
instead  of  75  hours  when  only  one  cell  is  used. 
It  is  therefore  more  economical  to  use  two  cells 
per  tube  than  one  cell  per  tube. 

Fig.  4  shows  the  effect  on  service  life  of  vari- 
ous rates  of  discharge.  This  curve  was  obtain- 
ed by  operating  cells  two  hours  per  day  to  a 
cut-off  of  1.1  volts  at  different  currents.  At 
discharges  of  one  quarter  ampere,  the  service 
life  is  75  hours.  At  one  eighth  ampere,  it  is 
175  hours,  and  at  one  twelfth  ampere,  it  is 
258  hours. 

These  discharge  rates  correspond  to  the  use 
of  one,  two  or  three  cells  for  each  WD- 11 
tube  in  the  set.  The  service  for  one  cell  is 
75  hours;  for  two  cells,  87^  hours  per  cell;  and 
for  three  cells,  86  hours  per  cell.  This  shows 
that  while  it  is  more  economical  to  use  two 
cells  per  tube  than  one  cell,  no  further  increase 
in  economy  is  obtained  by  using  more  than  two 
cells  per  tube. 


Still  another  factor  affecting  the  service  life 
of  dry  cells  is  the  average  number  of  hours  the 
cells  are  used  each  day.  In  radio  reception, 
this  is  an  extremely  variable  factor,  and  no  one 
knows  just  how  many  hours  per  day  the  aver- 
age set  is  used.  It  probably  lies  between  two 
and  three  hours  a  day,  although  individual 
cases  will  vary  considerably  from  this  figure. 

The  curves  in  Fig.  5  serve  to  show  how  dif- 
ferent periods  of  use  affect  the  service  life  of  dry 
cells.  Curve  A  is  for  one  quarter  ampere  to  a 
cut-off  of  1 . 1  volts,  and  curve  B  is  for  one  eighth 
ampere  to  the  same  cut-off  point. 

It  will  be  observed  from  a  study  of  Curve  B 
that  when  the  periods  of  use  are  below  i|  or  2 
hours  per  day,  the  service  life  is  slightly  re- 
duced. This  is  due  to  the  natural  depreciation 
which  takes  place  in  all  dry  .cells  when  not  in 
use.  On  the  other  hand,  when  the  service 
periods  are  greater  than  three  hours  a  day, 
the  number  of  hours  of  useful  life  is  again  de- 
creased, due  to  the  lack  of  sufficient  time  be- 
tween periods  of  use  for  complete  recupera- 
tion. Between  these  two  extremes  is  a  point 
where  maximum  service  will  be  obtained,  and 
in  this  case,  it  is  somewhere  between  two  and 
three  hours  per  day.  For  each  current  dis- 
charge, there  is  always  this  point  of  maximum 
service,  but  it  is  different  for  each  current.  For 
one  quarter  ampere  discharge,  maximum  service 
will  be  obtained  by  using  the  cells  between  one 
half  and  one  hour  per  day. 

This  further  emphasizes  the  advisability 
of  using  two  dry  cells  for  each  WD-i  1  tube 
in  the  set.  When  this  is  done,  maximum 
service  is  obtained  by  operating  the  set  two  or 
three  hours  per  day,  and  in  all  probability, 


2W 

\ 

V 

1B0 

too 

2 HOURS  PEE  DAY  TO .J4-V0LT5  CUT-  OFF! 

(V 

20 

OIO  0  2D  0.30  O.4-0  O.SO  O.&O 


FIG.  4 

1 1  is  evident  that  the  less  current  you  take  from  a  dry  cell 
the  longer  its  life  will  be.  However,  it  will  deteriorate 
of  its  own  accord  from  too  little  use,  as  shown  in  Fig.  5 


Six-Inch  Dry  Cells  and  WD-ii  Tubes 


77 


220 

tea 



\ 

gAMR  DISCMARGE  TO  M- VOLT  CUT-OFF. 

€0 

a 

\ 

\ 

4lAMt>  DISCHARGE,  xo  VI  VOLT  CUT-OFF 

0 

HOURS  USE  PtR  PAY 


FIG.  5 

Different  periods  of  service  may  be  expected  where  the 
amperage  and  the  hours  of  service  per  day  vary.  By 
properly  proportioning  your  ceils  to  meet  the  demands 
of  your  particular  service,  you  may  secure  the  greatest 
life   for  your  A  battery  at  the   least  expenditure 

this  figure  comes  nearest  to  average  conditions 
of  use. 

The  age  of  a  dry  cell  when  put  into  use  has 
some  influence  on  the  amount  of  service  which 
can  be  obtained  from  it.  The  slow  depreciation 
going  on  in  all  idle  dry  cells,  has  the  effect  of 
reducing  the  useful  service  life.  However, 
in  well-made  cells,  this  depreciation  factor 
does  not  become  appreciable  for  many  months. 
The  date  given  in  the  curves,  Figs.  3  to  5  apply  to 
dry  cells  not  more  than  six  months  old.  The  pos- 
sibility of  a  purchaser  securing  a  dry  cell  more 
than  six  months  old  is  extremely  remote,  if  he 
confines  his  purchases  to  cells  of  well-known, 
reliable  make,  for  such  cells  enjoy  a  wide 
sale  and  consequently  the  dealer's  stock  turns 
over  rapidly,  insuring  fresh  cells  always  on 
hand. 

Let  us  assume  that  the  average  user  has 
purchased  two  standard  six-inch  dry  cells  for 
his  WD-ii  tube  which  he  uses  between  two 
and  three  hours  daily.  Under  these  conditions 
he  should  obtain  175  hours  of  service  from  the 
battery,  but  he  sometimes  fails  to  do  this  by  a 
considerable  margin.  On  first  thought  he  is  apt 
to  blame  the  dry  cells.  In  the  vast  majority 
of  cases  this  is  unjust,  because  cells  made  by 
reliable  manufacturers  are  not  only  carefully 
constructed,  but  are  constantly  inspected  dur- 
ing process  of  manufacture  and  carefully  tested 
before  shipment.  The  chances  for  defective 
cells  getting  into  the  hands  of  the  user  are 


practically  zero.  The  failure  to  get  adequate 
service  is  usually  caused  by  the  user  himself. 
Just  what  does  the  operator  do  that  shortens 
the  life  of  his  cells? 

He  may  fail  to  adjust  his  filament  rheostat 
properly.  Suppose,  in  adjusting  his  rheostat, 
the  operator  obtains  a  current  of  0.28  ampere 
instead  of  0.25  ampere.  This  is  easily  possible, 
for  the  average  operator  has  no  means  of 
accurately  determining  the  filament  current. 
By  doing  just  this  one  little  thing,  he  reduces  the 
service  life  of  his  dry  cells  25  hours,  as  shown  in 
Figure.  4. 

Some  filament  rheostats  are  responsible  for 
decreased  service  life  of  dry  cells.  It  may  seem 
a  far  cry  from  a  filament  rheostat  to  dry  battery 
life,  but  in  reality  the  two  are  closely  associated. 

The  construction  of  certain  rheostats  is  such 
that  it  is  impossible  to  cut  out  all  the  resistance. 
With  the  indicator  at  the  "all  out"  position, 
there  still  remains  a  small  amount  of  resistance 
in  the  circuit,  which  prevents  the  full  battery 
voltage  from  reaching  the  tube.  This  voltage 
drop  is  always  present,  and  means  that  the 
cut-off  voltage  of  the  cell  must  be  greater  than 
the  tube  voltage  by  an  amount  equal  to  the 
drop  through  the  fixed  resistance.  Even  if 
this  resistance  is  so  small  as  to  cause  a  drop  of 
only  .05  volt,  this  will  reduce  the  service  life 
of  the  cells  ten  or  twelve  hours. 

The  resistance  of  the  wires  used  to  connect 
the  battery  to  the  tubes  has  a  similar  effect. 
Resistance  measurement  of  typical  installations 
have  been  made,  and  in  some  cases,  the  resultant 
voltage  drop  has  been  found  to  be  as  much  as 
1  volt.  This  immediately  raises  the  cut-off 
point  from  1.1  to  1.2  volts,  with  a  correspond- 
ing decrease  in  battery  service  life  of  45  hours. 

To  get  maximum  service  from  six-inch  dry 
cells  in  connection  with  WD-ii  tubes,  the 
following  should  be  observed: 

Obtain  fresh  cells  by  purchasing  those  of 
reliable  manufacture  which  enjoy  a  large  sale. 

Use  two  cells  connected  in  multiple  for  each 
tube  in  the  radio  receiving  set. 

Never  subject  the  tube  to  a  voltage  in  excess 
of  its  rating,  that  is,  1.1  volts. 

Install  the  battery  so  that  there  will  be  the 
minimum  resistance  in  the  leads  between  it  and 
the  tubes.  Locate  the  battery  as  close  as 
possible  to  the  tubes,  and  use  heavy  wires  for 
connections. 


Revised  List  of  U.  S.  and  Canadian 
Broadcasting  Stations 

This  list  includes  all  commercial  broadcasting  stations  in  the  United  States  licensed  up  to  March  18,  1923. 
*denotes  stations  that  were  deleted  up  to  that  date.  The  Canadian  list,  comprising  59  stations,  includes 
all  that  were  licensed  before  February  21,  1923.  Additional  lists,  with  deletions,  are  printed  every  month 
in  Radio  Broadcast. 


KACY      Western  Union  College  Le  Mars,  Iowa 

KAD         Y.  M.  C.  A  Denver,  Colo. 

KDKA  Westinghouse  Electric  &  Mfg.  Co.  East  Pittsburgh,  Pa. 

KDN        Meyberg  Co.,  fceo  J  San  Francisco,  Calif. 

KDPM  Westinghouse  Elect.  &  Mfg.  Co.          Cleveland,  Ohio. 

KDPT  Southern  Electrical  Co.   .     .     .         San  Diego,  Calif. 

KDYL  Telegram  Publishing  Co.      .     .  Salt  Lake  City,  Utah 

KDYM     Savoy  Theatre   San  Diego,  Calif. 

KDYN  Great  Western  Radio  Corp  .     .  Redwood  City,  Calif. 

*KDYO  Carlson  &  Simpson    ......    San  Diego,  Calif. 

KDYQ  Oregon  Institute  of  Technology .      .       Portland,  Oreg. 

*KDYR  Pasadena  Star-News  Pub.  Co.    .     .       Pasadena,  Cal. 

KDYS      The  Tribune,  Inc  Great  Falls,  Mont. 

KDYV  Cope  &  Cornwell  Co.      ...  Salt  Lake  City,  Utah 

KDYW     Smith,  Hughes  &  Co   Phoenix,  Ariz. 

KDYX     Star-Bulletin  Pub.  Co  Honolulu,  T.  H. 

KDZA      Arizona  Daily  Star  Tucson,  Ariz. 

KDZB      Frank  E.  Siefert  Bakersfield,  Calif. 

KDZE      The  Rhodes  Co  Seattle,  Wash. 

KDZF  Automobile  Club  of  So.  Calif.           Los  Angeles,  Calif. 

KDZG      Cyrus  Peiree  &  Co  San  Francisco,  Calif. 

KDZH      Fresno  Evening  Herald  Fresno,  Calif. 

KDZ1       Electric  Supply  Co   Wenatchee,  Wash. 

KDZK  Nevada  Machinery  &  Electric  Co.  .     .     .  Reno,  Nev. 

K.DZL  Rocky  Mountain  Radio  Corp.    .     .          Ogden,  Utah 

KDZM     E.  A.  Hollingworth  Centralia,  Wash. 

*KDZP     Newbery  Elect.  Corp  Los  Angeles,  Cal. 

KDZQ      William  D.  Pyle  Denver,  Colo. 

KDZR  Bellingham  Publishing  Co.    .     .     .  Bellingham,  Wash. 

K.DZT      Seattle  Radio  Assn  Seattle,  Wash. 

KDZU  Western  Radio  Corporation  ....    Denver,  Colo. 

*KDZW    Claude  W.  Gerdes  San  Francisco,  Calif. 

KDZX  Glad  Tidings  Tabernacle      .     .    San  Francisco,  Calif. 

KDZZ       Kinney  Bros.  &  Sipprell  Everett,  Wash. 

KFAB      Pacific  Radiofone  Co   Portland,  Oreg. 

*KFAC     Glendale  Daily  Press  Glendale  Calif. 

KFAD  McArthur  Bros.  Mercantile  Co. .     .     .   Phoenix,  Ariz. 

KFAE  State  College  of  Washington .     .     .      Pullman,  Wash. 

KFAF      Western  Radio  Corp   Denver,  Colo. 

KFAJ       University- of  Colorado  Boulder,  Colo. 

KFAN      Electric  Shop  Moscow,  Idaho 

K.FAP      Standard  Publishing  Co.l  Butte.  Mont. 

KFAQ      City  of  San  Jose  San  Jose,  Calif. 

KFAR      Olesen,  O.  K  Hollywood,  Calif. 

KFAS       Reno  Motor  Supply  Co  Reno,  Nev. 

KFAT      Donohue,  Dr.  S.  T  Eugene,  Oregon 

KFAU  Independent  School  District  of  Boise  City  Boise,  Idaho 

KFAV      Cooke  &  Chapman  Venice,  Calif. 

KFAW      Radio  Den,  The  Santa  Ana,  Calif. 

KFAY  Virgin  Milling  Co.,  W.  J. .     .     .    Central  Point,  Oreg. 

KFAZ      Weatherell,  C.  H  Readley,  Calif. 

*KFBA  Ramey  &  Bryant  Radio  Co.      .     .     Lewiston,  Idaho 

KFBB       Buttrey  &  Co.,  F.  A  Havre,  Mont. 

KFBC      Azbill,  W.  K  San  Diego,  Calif. 

KFBD      Welsh,  Clarence  V  Hanford,  Calif. 

KFBE       Horn,  Reuben  H  San  Luis  Obispo,  Calif. 

KFBF      Smith,  F.  H  Butte,  Mont. 

KFBG  First  Presbyterian  Church    ....  Tacoma,  Wash. 

*KFBJ      Boise  Radio  Supply  Co  Boise,  Idaho 

KFBK      Kimball-Upson  Co  Sacramento,  Calif. 

KFBL      Leese  Bros  Everett,  Wash. 

*KFBM    Cook  &  Foster  Astoria,  Ore. 

*KFBN     Borch  Radio  Corp  Oakland,  Cal. 

*KFBQ     Savage  Elect.  Co  Prescott,  Ariz. 

KFBS  Gas  &  Elect.  Supply  Co.       ...       Trinidad,  Colo. 

KFBU  Thomas,  Bishop  N.  S.     .     .     .      Laramie,  Wyoming 

KFBV  Clarence  O.  Ford  ....     Colorado  Springs,  Colo. 

*KFC  Northern  Radio  &  Electric  Co.  .     .        Seattle,  Wash. 

KFCB  Nielsen  Radio  Supply  Co.     .     .     .        Phoenix, .Ariz. 

KFCC       Auto  Supply  Co   Wallace,  Idaho 

KFCD      Salem  Elect.  Co  Salem,  Oregon 

KFCF       Frank  A.  Moore  Walla  Walla,  Wash. 

K.FCH  Electric  Service  Station   ....       Billings,  Mont. 

KFCK  Colorado  Springs  Radio  Co.  .    Colorado  Springs,  Colo. 

KFCL  Los  Angeles  Union  Stock  Yards .       Los  Angeles,  Calif. 

KFCM  Richmond  Radio  Shop    ....    Richmond,  Calif. 

KFCP       Flygare,  Ralph  W  Ogden,  Utah 

KFCQ  Motor  Service  Station     .     .     .        Casper,  Wyoming 

KFCV      Mahaffey,  Jr.,  Fred  Houston,  Texas 

KFCY      Western  Union  College  Le  Mars,  Iowa 


KFCZ  Omaha  Central  High  School      .     .         Omaha,  Neb. 

KFDA      Adler's  Music  Store   Baker,  Oregon 

KFDB  Mercantile  Trust  Co.  of  California  San  Francisco,  Cal. 

KFDC      Radio  Supply  Co   Spokane,  Wash. 

KFDD      St.  Michael's  CathedraJ  Boise,  Idaho 

KFDF      Wyoming  Radio  Corp  Casper,  Wyoming 

KFDH      University  of  Arizona  Tucson,  Ariz. 

KFDJ  Oregon  Agricultural  College  .     .         Corvallis,  Oregon 

KFDL  Knight-Campbell  Music  Co.      .     .     .    Denver,  Colo. 

KFDO  Cutting,  H.  Everett,  ....          Bozeman,  Mont. 

KFDP  Hawkeye  Radio  &  Supply  Co.    .     .  Des  Moines,  Iowa 

KFDR  Bullock's  Hardware  &  Sporting  Goods  .       York,  Neb. 

KFDU      Nebraska  Radio  Elect.  Co  Lincoln,  Neb. 

KFDV  Gilbrech  &  Stinson     ....        Fayetteville,  Ark 

KFDY  South  Dakota  State  College  .     .    .      Brookings,  S.  D. 

KFDZ      Harry  O.  Iverson  Minneapolis,  Minn. 

KFEB       The  City  of  Taft   Taft,  Calif. 

KFEC      Meir  &  Frank  Co.  Portland,  Oregon 

*KFED  Billings  Polytechnic  Institute          Polytechnic,  Mont. 

KFEJ       Guy  Greason  Tacoma,  Wash. 

KFEL       Winner  Radio  Corp  Denver,  Colo. 

KFEP       Radio  Equipment  Co  Denver,  Colo. 

KFEQ      Scroggin,  J.  L.   Oak,  Neb. 

KFER  Auto  Electric  Service  Co.,  Inc.  .     .  Fort  Dodge,  Iowa 

KFEV  Radio  Electric  Shop  ....      Douglas,  Wyoming 

KFFA      Dr.  R.  O.  Shelton  San  Diego,  Calif. 

KFFJ       Jenkins  Furniture  Co  Boise,  Idaho 

KFFQ  Marksheffel  Motor  Co.    .     .    Colorado  Springs,  Colo. 

KFFV      Graceland  College  Lamoni,  Iowa 

KFGB      Loewenthal  Bros  Pueblo,  Colo. 

KFGF  Buchanan  Stevens  &  Co. .     .     .      Mt.  Vernon,  Wash. 

KFGG      Astoria  Budget  Astoria,  Oregon 

KFGH  Leland  Stanford  Jr.  Univ.     Stanford  University,  Calif. 

KFHB      P.  L.  Boardwell  Hood  River,  Ore. 

K.FHJ  Fallon  Company   .....  Santa  Barbara,  Calif. 

KFI  Anthony,  Earle  C,  Inc.  .     .     .      Los  Angeles,  Calif. 

KFU  Precision  Shop,  The   ......  Gridley,  Calif. 

KFV  Foster-Bradbury  Radio  Store    .     .     .  Yakima,  Wash. 

KFZ  Doerr-Mitchell  Electrical  Co.     .     .      Spokane,  Wash. 

KGB  Mullins,  Electric  Co.,  Wm.  A.    .     .     .  Tacoma,  Wash. 

KGC  Electric  Lighting  Supply  Co.     .     .   Hollywood,  Calif. 

*KCF  Pomona  Fixture  &  Wiring  Co.    .     .     .  Pomona,  Calif. 

KGG  Hallock  &  Watson  Radio  Service     .     .   Portland,  Ore. 

KGN  Northwestern  Radio  Mfg.  Co.    .    .     .   Portland,  Ore. 

KGO  Altadena  Radio  Laboratory  .               Altadena,  Calif. 

KGU        Mulrony,  Marion  A   Honolulu,  Hawaii 

KGW       Portland  Oregonian  Portland,  Oregon 

KGY  St.  Martins  College  (Rev.  S.  Ruty) .     .    Lacey,  Wash. 

KHD  Aldrich  Marble  &  Granite  Co.  Colorado  Springs,  Colo. 

KHJ        Kierulff  &  Co.,  C.  R  Los  Angeles,  Calif. 

KHQ        Wasmer,  Louis  Seattle.  Wash. 

*KJC       Standard  Radio  Co  Los  Angeles.  Calif. 

KJJ         Radio  Shop,  The  Sunnyvale,  Calif. 

KJQ         Gould.  CO  Stockton,  Calif. 

KJR         Kraft,  Vincent  I  Seattle,  Wash. 

KJS  Bible  Institute  of  Los  Angeles    .      Los  Angeles,  Calif. 

KLB         Dunn  &  Co.,  J.  J  Pasadena,  Calif. 

KLN  Noggle  Electric  Works     ....     Monterey,  Calif. 

KLP         Kennedy  Co.,  Colin  B  Los  Altos,  Calif. 

KLS         Warner  Brothers  Oakland,  Calif. 

KLX        Tribune  Publishing  Co   Oakland,  Calif. 

KLZ         Reynolds  Radio  Co  Denver.  Colorado 

KMC       Lindsay,  Weathereill  &  Co  Reedley,  Calif. 

KM  I  San  Joaquin  Light  &  Power  Corporation  Fresno,  Calif. 

KNJ  Roswell  Public  Service  Co.    .          .    Roswell,  N.  Mex. 

KNN        Bullock's  Los  Angeles,  Calif. 

KMO       Love  Electric  Co  Tacoma,  Wash. 

KNR  Beacon  Light  Co.  .....     .'Los  Angeles,  Calif. 

KNT  North  Coast  Products  Co.    .     .     .     Aberdeen,  Wash. 

KNV        Radio  Supply  Co  Los  Angeles,  Calif. 

KNX  Electric  Lighting  Supply  Co.            Los  Angeles,  Calif. 

KOA  Young  Men's  Christian  Association .        Denver,  Colo. 

KOB  New  Mexico  College  of  Agriculture  and  Mechanical  Arts 

State  College,  N.  Mex. 

KOE        Spokane  Chronicle  Spokane,  Wash. 

KOG  Western  Radio  Electric  Co.  .         .  Los  Angeles,  Calif. 

KON        Holzwasser  Inc  Dan  Diego,  Calif. 

KOP        Detroit  Police  Dept   Detroit,  Michigan 

KOQ        Modesto  Evening  News  Modesto,  Calif. 

KPO        Hale  Bros,.  Inc  San  Francisco,  Calif. 

KQI  University  of  California  ....      Berkeley,  Calif. 


The  Grid 


QUESTIONS  AND  ANSWERS 

The  Grid  is  a  Question  and  Answer  Department  maintained  especially  for  the  radio  amateurs.  Full 
answers  will  be  given  wherever  possible.  In  answering  questions,  those  of  a  like  nature  will  be  grouped 
together  and  answered  by  one  article.  Every  effort  will  be  made  to  keep  the  answers  simple  and  direct, 
yet  fully  self-explanatory.  Questions  should  be  addressed  to  Editor;  "  The  Grid,"  Radio  Broadcast, 
Garden  City,  N.  Y.  The  letter  containing  the  questions  should  have  the  full  name  and  address  of  the 
writer  and  also  his  station  call  letter,  if  he  has  one.    Names,  however,  will  not  be  published. 


Operating  Loud-Speakers  at  a  Distance 

Please  tell  me  how  many  loud-speakers  {say  Magnavoxes) 
could  be  worked  off  a  two-stage  audio-frequency  set — and 
is  there  any  limitation  to  the  distance  they  could  he  placed 
from  the  set,  as  in  neighbors' _  houses  {the  receiving  set  being 
in  one  house,  and  the  others  having  the  loud-speakers  operated 
from  the  same  set  ?) 

W.  H.  M.,  Miami,  Arizona. 

THEORETICALLY,  any  number  of  loud-speakers 
may  be  operated  in  series  from  one  set,  if  the  im- 
pedance and  voltage  are  corrected  and  the  signal 
on  a  single  loud-speaker  is  strong.  Practically,  it  should 
not  be  difficult  to  operate  a  dozen  or  so  in  this  manner. 

However,  there  are  much  more  definite  limits,  imposed 
principally  by  capacity  effects,  on  the  distance  which  such 
loud-speakers  may  be  operated  from  the  receiving  appara- 
tus. The  leads  running  to  the  loud-speaker  are  virtually  a 
shunt  capacity,  and  the  loss  in  signal  strength  is  comparable 
to  that  occasioned  by  shunting  too  large  a  condenser  across 
the  telephone  receivers.  In  some  cases  the  capacity  may 
cause  distortion,  though  in  the  majority  of  loud-speakers, 
this  would  be  counteracted  by  the  inductance  in  the  loud- 
speaker windings.  The  undesirable  effects  of  capacity  may 
be  somewhat  reduced  by  employing  a  single  wire  with 
a  ground  return. 

If  Magnavoxes  are  used,  it  is  suggested  that  a  separate 
six-volt  battery  be  located  in  the  immediate  vicinity  of 
each  Magnavox  to  excite  its  field. 

For  use  in  neighboring  houses,  assuming  the  total  length 
of  wire  to  be  less  than  eight  hundred  feet,  the  problem  is 
not  a  difficult  one.  In  consideration  of  both  economy  and 
simplicity,  we  suggest  using  loud- 
speakers having  permanent  fields, 
such  as  the  Western  Electric  (with- 
out power  amplifier.)  They  should 
be  connected  in  series,  Figure  I, 
using  well  insulated  wire  of  size 
number  twenty-four  or  larger,  with 
a  final  return  through  the  ground. 
As  the  wire  carries  a  comparatively 
high  voltage,  it  should  be  carefully 
insulated  wherever  braced  or  sup- 
ported. Forty  to  a  hundred  addi- 
tional volts  should  be  used  on  the 
final  step  of  amplification. 

For  farther  distances,  or  a  greater 
multiplicity  of  loud  talkers,  it  would 
be  best  to  distribute  the  signals 
from  the  first  step  of  the  receiver, 
and  equip  each  loud-talker  with  a 


separate  one-step  amplifier  using  individual  A  and  B 
batteries.  The  auxiliary  apparatus  would,  of  course,  be 
housed  under  the  same  roof  as  the  loud-speaker  itself. 
(Care  should- be  taken  in  running  the  lines  for  such  an  in- 
stallation, that  the  wires  are  not  closely  parallel  to  lighting 
or  power  leads,  for  all  induced  disturbances  will  be  ampli- 
fied.) With  this  arrangement,  Magnavoxes  may  be  con- 
veniently used,  the  externally  excited  fields  being  supplied 
from  the  amplifier  A  batteries. 

By  elaborating  on  this  latter  system,  it  should  be  prac- 
tical to  equip  the  houses  of  an  entire  village  with  loud- 
talkers  operated  from  a  single  well  located  receiver.  How- 
ever, before  undertaking  such  a  venture,  it  would  be  well 
to  consult  a  telephone  expert,  and  finally  to  do  the  actual 
installing  under  his  supervision. 

Tuned  Circuits 

What  relation  has  the  wavelength  to  which  the  plale  var- 
iometer is  tuned,  to  the  intercepted  wavelength? 

Can  regeneration  be  controlled  in  the  ultra-audion  circuit? 

What  would  be  the  advantage  of  using  both  a  tickler  and 
tuned  plate  circuit  simultaneously? 

L.  U.,  Bellefontaine,  Ohio. 


T! 


>HE  wavelength  of  the  plate  circuit  in  a  variometer 
regenerative  set  is  tuned  by  means  of  the  plate 
variometer  to  within  a  few  meters  of  the  wave  of  the 
received  signal.    The  degree  of  regeneration  increases  as 
the  resonance  point  in  approached,  until,  just  before  the 
plate  circuit  is  perfectly  tuned,  the  bulb  oscillates,  a  condi- 
{Continued  on  page  86) 


LOUD  SPEAKERS 


8o 


Radio  Broadcast 


KQL  Kluge,  Arno  A  Los  Angeles,  Calif. 

KQP  Appie  City  Radio  Club     ....  Hood  River,,  Ore. 

K.QT  Electric  Power  &  Appliance  Co. .  Yakima,  Wash. 

KQV  Doubleday-Hill  Electrical  Co.    .     .      Pittsburgh,  Pa. 

KQW  Herrold,  Charles  D  San  Jose,  Calif. 

KQY  Stubbs  Electric  Co   Portland,  Ore. 

K.RE  Maxwell  Electric  Co  Berkeley,  Calif. 

KSC  Hael  &  Co  San  Jose.  Calif. 

KSD  Post  Dispatch   St.  Louis,  Mo 

KSL  Emporium,  The  San  Francisco,  Calif. 

KSS  Prest  &  Dean  Radio  Research  Laboratory 

Long  Beach,  Calif. 

KTW  First  Presbyterian  Church    ....  Seattle,  Wash. 

KUO  The  Examiner  Printing  Co.  .  San  Francisco,  Calf. 

KUS  City  Dye  Works  &  Laundry  Co.       Los  Angeles,  Calif. 

KUY  Coast  Radio  Company    ....     El  Monte,  Calif. 

*KVQ  Hobrecht,  J.  C   Sacramento,  Calif. 

KWG  Portable  Wireless  Telephone  Co.  Stockton,  Calif. 

KWH  Los  Angeles  Examiner  .  Los  Angeles,  Calif. 

KXD  Herald  Publishing  Co  Modesto,  Calif. 

KXS  Braun  Corporation     ....       Los  Angeles,  Calif. 

*KYF  Thearle  Music  Co  San  Diego,  Calif. 

KGY  Hawley,  Willard  P..  Jr  Portland,  Ore. 

KYI  Alfred  Harrell  Bakersheld,  Calif. 

KYJ  Meyberg  Co.,  Leo  J  Los  Angeles,  Calif 

KYQ  Electric  Shop  Honolulu,  Hawai 

KYW  Westinghouse  Electric  &  Mfg.  Co    .     .       Chicago,  111. 

*KYY  Radio  Telephone  Shop,  The  .         San  Francisco,  Calif. 

KZC  Public  Market  &  Department  Stores  Co.  Seattle,  Wash. 

KZI  Cooper,  Irving  S  Los  Angeles,  Calif 

KZM  Allen,  Preston,  D  Oakland,  Calif. 

KZN  Deseret  News  Salt  Lake  City,  Utah 

KZV  Wenalchee  Battery  &  Motor  Co.     .  Wenatchee,  Wash. 

*KZY  Atlantic-Pacific  Radio  Supplies  Co. .     .  Oakland,  Calif 

KUO  Examiner  Printing  Co.     .  San  Francisco.  Calif. 

NAA  U.  S.  Government  Arlington,  Md. 

NOF  U.  S.  Navy  Anacostia,  Md. 

WAAB  Jensen,  Valdemar  -  .   New  Orleans,  La. 

WAAC  Tulane  University  of  Louisiana  .         New  Orleans.  La. 

WAAD  Ohio  Mechanics  Institute     .     .     .     Cincinnati,  Ohio 

WAAE  St.  Louis  Chamber  of  Commerce     .     .   St.  Louis,  Mo. 

WAAF  Union  Stock  Yards  &  Transit  Co.   .     Chicago,  Illinois 

*WAAG  Elliott  Electric  Co  Shreveport,  La. 

WAAH  Commonwealth  Electric  Co.       .     .       St.  Paul,  Minn. 

WAAJ  Eastern  Radio  Institute  Boston,  Mass. 

WAAK  Gimbel  Brothers   Milwaukee,  Wise. 

WAAL  Minnesota  Tribune  Co  Minneapolis,  Minn. 

WAAM  Nelson  Co.,  I.  R   .     .   Newark,  N.  J. 

WAAN  University  of  Missouri  Columbia,  Mo. 

+WAAO  Radio  Service  Co  Charleston,  W.  Va. 

WAAP  Taylor,  Otto  W  Wichita,  Kansas 

WAAQ  New  England  Motor  Sales  Co.  .     .  Greenwich.  Conn. 

*WAAR  Groves-Thornton  Haidware  Co.     Huntington,  W.  Va. 

WAAS  Georgia  Radio  Co  Decatur,  Ga. 

*WAAV  Athens  Radio  Co  Athens,  O. 

WAAW  Omaha  Grain  Exchange  Omaha,  Neb. 

WAAY  Yahrling-Raynor  Piano  Co.  .     .  Youngstown,  O. 

WAAZ  Hollister-Miller  Motor  Co.    .     .     .    Emporia,  Kansas 

WAH  Midland  Refining  Co   El  Dorado,  Kansas 

*WAAX  Radio  Service  Corp  Crofton,  Pa. 

WAJV  Indian  Pipe  Wire  Corp  Princeton,  Ind. 

WBA  Marshall-Gerkin  Co   Toledo,  Ohio. 

WBAA  Purdue  University      ....    West  Lafayette,  Ind. 

*WBAB  Potter,  Andrew  J  Syracuse,  N.  Y. 

WBAD  Sterling  Electric  Co.  &  Journal  Printing  Co. 

Minneapolis.  Minn. 

WBAE  Bradley  Polytechnic  Institute    ....   Peoria,  111. 

WBAFG  Middleton,  Fred  M  Morestown,  N.  J. 

WBAG  Diamond  State  Fibre  Co.      .     .     .       Bridgeport,  Pa. 

WBAH  Dayton  Co  Minneapolis,  Minn. 

WBAJ  Marshall,  Gerkin  Co   Toledo,  O. 

WBAM  Rennysen,  T.  B  New  Orleans,  La. 

WBAN  Wireless  Phone  Corporation  .     .     .       Paterson,  N.  J. 

WBAO  Millikin  University  Decatur,  111. 

WBAP  The  Star  Telegram       ....       Fort  Worth,  Texas 

WBAU  Republican  Publishing  Co.    .     .     .      Hamilton,  Ohio 

WBAV  Erner  &  Hopkins  Co  Columbus,  Ohio 

WBAW  Marietta  College  Marietta,  Ohio 

WBAX  John  H.  Stenger,  Jr   Wilkes-Barre,  Pa. 

WBAY  Amer.  Tel.  &  Tel.  Co  New  York,  N.  Y. 

WBL  T.  &  H.  Radio  Co   Anthony.  Kansas 

WBS  May  (Inc.)  D.  W  ^Newark,  N-  J. 

WBT  Southern  Radio  Corporation .     .     .     Charlotte,  N.  C. 

WBU  City  of  Chicago  •  Chicago,  111. 

WBZ  Westinghouse  Electric  &  Mfg.  Co    .  Springfield,  Mass. 

WCAB  Newburgh  News  Printing  &  Pub.  Co.  Newburgh,  N.  Y. 

WCAC  John  Fink  Jewelry  Co.     .     .     .  Fort  Smith,  Ark. 

WCAD  St.  Lawrence  University  Canton,  Ohio 

WCAE  Kaufmann  &  Baer  Co  Pittsburg,  Pa. 

WCAF  Michigan  Limehouse  &  Chemical  Co.     Rodgers,  Mich. 

WCAG  Daily  States  Publishing  Co.  .     .     .    New  Orleans,  La. 

WCAH  Entrekin  Electric  Co  Columbus,  O 

WCAJ  Nebraska  Wesleyan  University  University  Place,  Neb. 

WCAK  Alfred  P.  Daniel  Houston,  Tex. 

WCAL  St.  Olaf  College  Northfield.  Minn. 

WCAM  Villanova  College  Villanova,  Pa. 

WCAN  Southeastern  Radio  Telephone  Co.  .    Jacksonville,  Fla. 

WCAO  Sanders  &  Stayman  Co  Baltimore,  Md. 

WCAP  Central  Radio  Service  Decatur,  111. 

*WCAQ  Tri-State  Radio  Mfg.  &  Supply  Co  .     .  Defiance.  Ohio 

WCAR  Alamo  Radio  Electric  Co.     .     .     .  San  Antonio,  Tex. 


WCAS      William  Hood  Dunwoody  Industrial  Institute 


Minneapolis,  Minn. 

WCAT  S.  Dakota  State  School  of  Mines     Rapid  City,  S.  Dak. 

WCAU  Philadelphia  Radiophone  Co.     .     .    Philadelphia.  Pa. 

WCAV      J.  C.  Dice  Electric  Co  Little  Rock,  Ark. 

WCAX  University  of  Vermont    .     .     .           Burlington,  Vt. 

WCAY  Kesselmen  O'Drescoll  Co.     .     .     .     Milwaukee,  Wi9. 

*WCAZ  Compton,  Robert                                 Carthage,  111. 

WCE        Findley  Electric  Co  Minneapolis,  Minn. 

*WCJ       Gilbert  Co.,  A.  C  New  Haven,  Conn. 

WCK        Stix-Baer-Fuller  St.  Louis.  Mo. 

WCM       University  of  Texas  Austin,  Texas 

WCN       Clark  University  Worcester,  Mass. 

WCX        Detroit  Free  Press  Detroit,  Mich. 

WDAC      Illinois  Watch  Co  Springfield,  111. 

WDAD  Central  Kansas  Radio  Supply               Lindsberg,  Kan. 

WDAE      Tampa  Daily  Times   Tampa,  Fla. 

WDAF      Kansas  City  Star  Kansas  City,  Mo. 

WDAH     Mine  &  Smelter  Supply  Co  El  Paso,  Tex. 

WDAI       Hughes  Electrical  Corp  Syracuse,  N.  Y. 

WDAJ  Atlanta  &  West  Point  R.  R.  Co.,       College  Park,  Ga. 

WDAK  The  Courant    .     .     .     .     .     .     .     Hartford,  Conn. 

WDAL      Florida  Times  Union  Jacksonville,  Fla. 

WDAM     Weston  Electric  Co  New  York,  N.  Y. 

*WDAN    Glenwood  Radio  Corp  Shreveport,  La. 

WDAO     Automotive  Electric  Co  Dallas,  Texas 

WDAP      Drake  Hotel  Chicago,  111. 

*WDAQ  Hartman-Riker  Electric  Machine  Co.   Brownsville,  Pa. 

*WDAR    Lit  Bros  Philadelphia,  Pa. 

WDAS      Samuel  W.  Waite  Worcester,  Mass. 

WDAU      Slocum  &  Kilburn  New  Bedford,  Mass. 

*WDAV  Muskogee  Daily  Phoenix .     .     .     .     Muskogee,  Okla. 

WDAX  First  National  Bank  ....        Centerville,  Iowa 

WDAY     Kenneth  M.  Hance  Fargo,  N.  D. 

WDM  Church  of  the  Covenant  .     .     .       Washington,  D.  C. 

WDT  Ship  Owners  Radio  Service   .     .     .    New  York,  N.  Y. 

*WDV      Yeiser,  John  O.,  Jr  Omaha,  Nebraska 

WDW  Radio  Construction  &  Electric  Co.    Washington,  D.  C. 

*WDY  Radio  Corp.  of  America  ....  Roselle,  Park,  N.  J. 

WDZ        Bush,  James  L  ■  .     .      Tuscola,  111. 

WEAA      Fallain  &  Lathrop  Flint,  Mich. 

WEAB  Standard  Radio  Equipment  Co..          Fort  Dodge,  la. 

WEAC  Baines  Electric  Service  Co.  .            Terre  Haute,  Ind. 

WEAD  Northwest  Kansas  Radio  Sup.  Co.  .       Atwood,  Kans. 

WEAE  Virginia  Polytechnic  Institute               Blacksburg,  Va. 

WEAF  American  Tel.  &  Tel.  Co.      .     .         New  York,  N.  Y. 

WEAG  Nichols-Hineline-Bassett      .     .     .     Edgewood,  R.  I. 

WEAH  Wichita  Board  of  Trade  &  Landers  Radio  Co. 

Wichita,  Kans. 

WEAI       Cornell  University  Ithaca,  N.  Y. 

WEAJ  University  of  South  Dakota  .     .     .    Vermillion,  S.  D. 

WEAK  Julius  B.  Abercrombie     ....      St.  Joseph,  Mo. 

WEAM  Borough  of  North  Plainfield       .  North  Plainfield,  N.  J. 

WEAN      Shepard  Co  Providence,  R.  I. 

WEAO  Ohio  State  University     ....     Columbus,  Ohio 

WEAP      Mobile  Radio  Co  Mobile,  Ala. 

WEAQ  Young  Men's  Christian  Association .          Berlin,  N.  H. 

WEAR  Baltimore  American  &  News  Pub.  Co.  Baltimore,  Md. 

WEAS      Hecht  Co  Washington.  D.  C. 

WEAT      John  J.  Fogarty  Tampa,  Fla. 

WEAU      Davidson  Bros.  Co  Sioux  City,  Iowa 

WEAV  Sheridan  Electric  Service  Co.     .     .      Rushville,  Neb. 

WEAW     Arrow  Radio  Lab  Anderson,  Ind. 

WEAX     T.  J.  M.  Daly  Little  Rock,  Ark. 

WEAY      Will  Horwitz,  Jr  Houston,  Tex. 

WEAZ      Donald  Redmond  Waterloo,  Iowa 

WEB        Benwood  Co  St.  Louis,  Mo. 

WEH        Midland  Refining  Co  Tulsa,  Okla. 

WEV  Hurlburt-Still  Electrical  Co.       ...    Houston,  Tex. 

WEW       St.  Louis  University  St.  Louis,  Mo. 

WFAA      A.  H.  Belo  &  Co   Dallas,  Tex. 

WFAB      Carl  F.  Woese  Syracuse,  N.  Y. 

WFAC      Superior  Radio  Co  Superior.  Wis. 

WFAD  Watson  Weldon  Motor  Supply  Co.      .      Salina,  Kan. 

WFAF      H.  C.  Spratley  Co  Poughkeepsie,  N.  Y. 

WFAG  Radio  Engineering  Laboratory  .     .    Waterford,  N.  Y. 

WFAH      Electric  Supply  Co  Port  Arthur,  Tex. 

WFAJ  Hi-Grade  Wireless  Instrument  Co.  .      Asheville,  N.  C. 

WFAK     Domestic  Electric  Co  Brentwood,  Mo. 

WFAL  Houston  Chronicle  Publishing  Co.  .        Houston.  Tex. 

WFAM  Times  Publishing  Co.               .     .    St.  Cloud,  Minn. 

WFAN  Hutchinson  Electric  Service  Co. .      Hutchinson,  Minn. 

WFAP      Brown's  Business  College  Peoria,  111. 

WFAQ  Missouri  Wesleyan  College  &  Cameron  Radio  Co. 

Cameron,  Mo. 

*WFAR    Hall  &  Stubbs  Stanford,  Me. 

WFAS  United  Radio  Corporation    .     .        Fort  Wayne,  Ind. 

WFAT  Daily  Argus  Leader    ....     Sioux  Falls.  S.  Dak. 

WFAU      Lewis,  Edwin  C  Inc  Boston,  Mass. 

WFAV      University  of  Nebraska  Lincoln,  Neb. 

WFAW     Miami  Daily  Metropolis  Miami,  Fla. 

WFAX      Kent,  Arthur  L  Binghamton,  N.  Y. 

WFAY  Daniels  Radio  Supply  Co.     .     .     Independence,  Kan. 

WFAZ  South  Carolina  Radio  Shop  .     .         Charleston,  S.  C. 

WFI  Strawbridge  &  Clothier    .     .     .         Philadelphia,  Pa. 

*WFO       Rike-Kumler  Co  Dayton,  Ohio 

WFY        Cosradio  Co  Wichita,  Kansas 

WGAB     QRV  Radio  Co  Houston,  Tex. 

WGAC  Orpheum  Radio  Stores  Co.    .     .     .     Brooklyn,  N.  Y. 


WGAD     Spanish-American  School  of  Radio  Telegraphy 

Ensenada,  Porto_Rico 


RADIO  BROADCAST  ADVERTISER 


CeloroN 

STANDATOJ  RADIO  PANEL 


^RD  RADIO  PANE! 


CeloroN  ft- 


One  of  these  panels  fits  jowr  set 


YESTERDAY  you  would  have 
had  to  wait  while  the  size  was 
cut  from  sheet  stock.  Today  you  can 
get  the  panel  you  need  immediately. 
Celoron  Radio  Panels  come  in  stand- 
ard sizes,  one  of  which  will  be  right 
for  any  set  you  may  build. 

Each  Celoron  Panel  is  already  cut 
and  wrapped  ready  for  you  to  take 
home.  Full  instructions  for  working 
and  finishing  are  on  the  glassine 
paper  around  every  panel. 

The  sizes  have  been  selected  only 
after  careful  study  of  present-day 
needs.  Your  dealer  should  be  able 
to  supply  you  with  any  of  the  fol- 
lowing sizes: 

1.  — 6x  7x£ 

2.  —7x  9xJ  5.- 

3.  — 7xl2x^  6.- 

7.— 12  x  14  x 

Also  comes  in  sheets  and  can  be  cut  in  special  sizes 
zc-hen  desired. 


4.— 7x  18  x  & 
-9  x  14  x 
-7  x  2 1  x  T3g- 


Condensite  Celoron,  the  material 
used  for  these  panels,  has  high  insu- 
lating qualities,  high  dielectric 
strength,  and  low  dielectric  losses. 
It  is  used  by  many  of  the  leading 
manufacturers  of  radio  equipment. 
It  is  easily  machined  and  can  be 
'sawed,  drilled,  turned,  or  milled. 

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We  have  prepared  an  attractive 
booklet,  "Tuning  in  on  a  New 
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every  radio  fan  and  will  be  sent  to 
you  free  of  charge  upon  request. 
Write  today. 


Diamond  State  Fibre  Company 


BRIDGEPORT 


PENNSYLVANIA 


(near  Philadelphia) 

Offices  in  Principal  Cities 
In  Canada:  Diamond  State  Fibre  Co.,  of  Canada  Limited,  245  Carlaw  Ave.,  Toronto 


To  radio  Celoron  Radio  Panels  cut  in  standard  sizes  offer  an  exceptional  opportunity  for  quick  sales 
dealers  2      anc^  substantial  profit.    Write  for  special  dealer  price  list  showing  standard  assortments. 


CONDENSITE 


STANDARD  RADIO  PANEL 


i>C  Tested  and  approved  by  Radio  Broadcast 


82 


Radio  Broadcast 


WGAF  Goller  Radio  Service  Tulsa,  Okla. 

WGAH  New  Haven  Elect.  Co.     .  New  Haven.  Conn. 

WGAI  Southern  Equipment  Co  San  Antonio,  Tex. 

WGAJ  Gass,  W.  H   Shenandoah,  Iowa 

WGAK  Macon  Electric  Co   Macon.  Ga. 

WGAL  Lancaster  Electric  Supply  &  Const.  Co.  Lancaster,  Pa. 

WGAM  Orangeburg  Radio  Equipment  Co.     Orangeburg,  S.  C. 

WGAN  Lloyd,  Cecil  E  Pensacola,  Fla. 

WGAQ  Patterson.  W.  G  Shreveport,  La. 

WGAR  South  American   Fort  Smith,  Ark. 

*WGAS  Ray — Di — Co.  Organization  Chicago,  Illinois 

WGAT  American  Legion,  Dept.  of  Nebraska        Lincoln.  Neb. 

WGAU  Limb.  Marcus  G   Wooster,  Ohio 

WGAV  B.  H.  Radio  Co   Savannah,  Ga. 

WGAW  Albright,  Ernest  Co.  .     .     :  Philadelphia.  Pa. 

WGAX  Radio  Elect.  Co   Washington,  O. 

WGAY  North  Western  Radio  Co.,  Inc.  .     .        Madison,  Wis. 

WGAZ  South  Bend  Tribune  ...    South  Bend.  Ind. 

WGFi  Register  &  Tribune,  The  .  Des  Moines,  Iowa 

WGH  Montgomery  Light  &  Power  Co.        Montgomery,  Ala. 

WGI  American  Radio  &  Research  Corporation 

Medford  Hillside,  Mass. 

WGL  Howlett.  Thomas.  F.  J  Philadelphia,  Pa. 

WGM  Altanta  Constitution  .  ....      Atlanta,  Ga. 

WGR  Federal  Telephone  &  Telegraph  Co.     .   Buffalo,  N.  Y. 

WGU  Fair,  The  Chicago,  111. 

WGV  Interstate  Electric  Co  New  Orleans,  La. 

WGY  General  Electric  Co  Schenectady,  N.  Y. 

WHAA  State  University  of  Iowa       .     .     .     Iowa  City,  Iowa 

WHAB  Thompson,  Clark  W  Galveston,  Texas 

WHAC  Cole  Bros.,  Electric  Co   Waterloo,  Iowa 

WHAD  Marquette  University      ....     Milwaukee,  Wis. 

WHAE  Automotive  Electric  Serv.  Co.    .  Sioux  City,  Iowa 

*WHAF  Radio  Electric  Co  Pittsburgh,  Pa. 

WHAG  University  of  Cincinnati  ....        Cincinnati.  O. 

WHAH  Griffin.  John  T  Joplin.  Mo. 

WHAI  Radio  Equipment  &  Mfg.  Co.  Davenport,  Iowa 

WHAJ  Blueheld  Daily  Telegraph     .     .     .    Bluelield,  W.  Va. 

WHAK  Roberts  Hardware  Co.  .  Clarksburg,  W.  Va.- 

WHAL  Phillips.  Jeffery  &  Derby .     .     .     .       Lansing,  Mich. 

WHAM  University  of  Rochester  ....     Rochester,  N.  Y. 

WHAN  Southwestern  Radio  Co  Wichita.  Kan. 

WHAO  Hill,  F.  A  Savannah,  Ga. 

WHAP  Otta.  Dewey  L   Decatur,  111. 

WHAQ  Semmes  Motor  Co  Washington,  D.  C. 

WHAR  Paramount  Radio  &  Electric  Co.     Atlantic  City.  N.  J. 

WHAS  Courier  Journal  &  Louisville  Times.        Louisville,  Ky. 

WHAT  Yale  Democrat  &  Yale  Telephone  Co.  .       Yale,  Okla. 

WHAU  Corinth  Radio  Supply  Co  Corinth,  Miss. 

WHAV  Wilmington  Electrical  Specialty  Co.    Wilmington,  Del. 

WHAW  Pierce  Elect.  Co  Tampa,  Fla. 

WHAX  Holyoke  Street  Ry.  Co  Holyoke,  Mass. 

WHAY  Huntington  Press  Huntington,  Ind. 

WHAZ  Rensselaer  Polytechnic  Institute   .  Troy,  N.  Y. 

WHA  University  of  Wisconsin  ....        Madison,  Wis. 

WHB  Sweeney  School  Co  Kansas  City,  Mo. 

WHD  West  Virginia  University .  .   Morgantown,  W.  Va. 

WHK  Cox,  Warren  R.     .     .  .    Cleveland,  O. 

WHN  Ridgewood  Times  Printing  &  Publishing  Co. 

Ridgewood,  N.  Y. 

WHQ  Rochester  Times  Union   ....    Rochester,  N.  Y. 

WHU  Duck  Co.,  William  B  Toledo.  Ohio 

*WHW  Seeley.  Stuart,  W  East  Lansing,  Mich. 

WHX  Iowa  Radio  Corporation  ....  Des  Moines,  Iowa 

*WIAA  Waupaca  Civic  &  Commerce  Assn.  .       Wauoaca,  Wis. 

WIAB  Joslyn  Automobile  Co   Rockford,  111. 

WIAC  Galveston  Tribune  Galveston,  Texas 

WIAD  Ocean  City  Yacht  Club   ....   Ocean  City,  N.  J. 

WIAE  Zimmerman,  Mrs.  Robert  E.  Venton,  Iowa 

WIAF  De  Cortin,  Gustav  A.  .     .         New  Orleans,  La. 

WIAG  Matthews  Elect.  Supply  Co. .     .     .   Birmingham,  Ala. 

WIAH  Continental  Radio  Mfg.  Co.       .     .         Newton.  Iowa 

WIAI  Heers  Stores  Co.    .     .  .     .      Springfield,  Mo. 

WIAJ  Fox  River  Valley  Radio  Supply  Co.  Neenah,  Wis. 

WIAK  Journal  Stockman,  The  Omaha,  Neb. 

WIAli  Standard  Radio  Service  Co.  .         .       Norwood,  Ohio 

WIAN  Chronicle  &  News  Pub.  Co.  .     .     .       Allentown,  Pa. 

WIAO  School  of  Engineering  of  Milwaukee  &  Wisconsin  News 

Milwaukee,  Wis. 

WIAP  Radio  Development  Corp.         .     .  Springfield,  Mass. 

WIAQ  Chronicle  Publishing  Co  Marion,  Ind. 

WIAR  Rudy  &  Sons,  J.  A  Paducah,  Ky. 

WIAS  Burlington  Hawk  Eye — Home  Electric  Co. 

Burlington,  Iowa 

WIAT  Noel,  Leon  T  Tarkio,  Mo. 

WIAU  American  Trust  &  Savings  Bank  .  Le  Mars,  Iowa 

WIAV  New  York  Radio  Laboratories   .      Binghamton,  N.  Y. 

WIAW  Saginaw  Radio  &  Elect.  Co.       .  "Saginaw,  Mich. 

*WIAX  Capital  Radio  Co  Lincoln.  Nebr. 

WIAY  Woodward  &  Lothrop  Washington,  D.  C. 

WIAZ  Electric  Supply  Sales  Co  Miami,  Fla. 

WIK  K.  &  L.  Electric  Co  McKeesport,  Pa. 

WIL  Continental  Electric  Supply  Co.        Washington,  D.  C. 

WIP  j  Gimbel  Brothers  Philadelphia,  Pa. 

WIZ  Cino  Radio  Mfg.  Co   Cincinnati,  O. 

WJAB  American  Radio  Co  Lincoln,  Neb. 

*WJAC  Redell  Co.,  The  Joplin,  Mo. 

WJAD  Jackson's  Radio  Eng.  Lab  Waco.  Texas 

*WJAE  Texas  Radio  Syndicate    .     .  San  Antonio,  Texas 

WJAG  Huse  Publishing  Co  Norfolk,  Neb. 

*WJAH  Central  Park  Amusement  Co.    .     ,         Rockford,  111. 


WJAJ  Y.  M.  C.  A   Dayton,  O. 

WJAK  White  Radio  Laboratory      ....    Stockdale,  O. 

*WJAL  Victor  Radio  Corp  Portland,  Me. 

WJAM  D.  M.  Perham  Cedar  Rapid3,  Iowa 

WJAN  Peoria  Star  &  Peoria  Radio  Sales  Co.  .        Peoria,  HI. 

WJAP  Kelly  Duluth  Co  Duluth,  Minn. 

WJAR  Outlet  Co.,  The  1    Providence,  R.  I. 

WSAS  Capper  Publications   Topeka,  Kans. 

WJAT  Kelley-Vawter  Jewelry  Co  Marshall,  Mo. 

*WJAV  Yankton  College  Yankton,  S.  D. 

WJAX  Union  Trust  Co  Cleveland,  O. 

WJAZ  Chicago  Radio  Lab  Chicago,  111. 

WJD  Howe,  Richard  H   Granville,  Ohio 

WJH  White  &  Boyer  Co  Washington,  D.  C. 

*WJK  Service  Radio  Equipment  Co.    .     .  Toledo,  Ohio 

WJT  Electric  Equipment  Co  Erie,  Pa. 

WJX  DeForest  Radio  Telephone  &  Telegraph  Co. 

New  York.  N.  Y. 

WJZ  Westinghouse  Electric  &  Mg.  Co.  Newark,  N.  J. 

WKA  Landans  Music  &  Jewelry  Co.    .         Wilkes-Barre,  Pa. 

WKAA  Paar,  H.  F.  &  Republican  Times     Cedar  Rapids.  Iowa 

WKAC  Star  Publishing  Co  Lincoln,  Neb. 

*WKAD  Looff,  Charles  East  Providence,  R.  I. 

WKAF  W.  S.  Radio  Supply  Co.  .     .     .    Wichita  Falls.  Texas 

1  WKAC  Bruce.  M.  D..  Edwin  T  Louisville,  Ky. 

WKAH  Planet  Radio  Co.        .     .     .      West  Palm  Beach.  Fia. 

WKAJ  Fargo  Plumbing  &  Heating  Co.  Fargo,  N.  D. 

WKAK  Okfuskee  County  News  ....       Okemah,  Okla. 

WKAL  Gray  &  Gray  Orange.  Tex. 

*WKAM  Hastings  Daily  Tribune  Hastings,  Neb. 

WKAN  Alabama  Radio  Mfg.  Co.      .     .     .  Montgomery,  Ala. 

WKAP  Flint.Dutee  Wilcox   Cranston,  R.  I. 

WKAQ  Radio  Corp.  of  Porto  Rico    .     .  San  Juan,  P.  R. 

WKAR  Michigan  Agri.  College    .     .         East  Lansing.  Mich. 

WKAS  Lines  Music  Co..  L.  E  Soringfield,  Mo. 

WKAT  Frankfort  Morning  Times     .     .     .      Frankfort,  Ind. 

WKAV  Laconia  Radio  Club   Laconia,  N.  H. 

WKAW  Turner  Cycle  Co  Beloit,  Wis. 

WKAX  Macfarlane,  William  A  Bridgeport,  Conn. 

WKAY  Brenau  College  Gainesville.  Ga. 

*WKAZ  Landau's  Music  &  Jewelry  Co.  Wilkes-Barre,  Pa. 

WKC  Zamoiski  Co.,  Joseph  M.      ...      Baltimore,  Md. 

WKN  Riechman-Crosby  Co  Memphis,  Tenn. 

WKY  Oklahoma  Radio  Shop  Oklahoma  City,  Okla. 

WLAB  Grossman,  George  F  Carrollton,  Mo. 

WLAC  North  Carolina  State  College     .     .     .  Raleigh,  N.  C. 

♦WLAD  Arvanette  Radio  Supply  Co  Hastings,  Neb. 

*WLAF  Johnson  Radio  Co  Lincoln,  Neb. 

WLAG  Cutting  &  Washington  Radio  Corp.  Minneapolis,  Minn 

WLAH  Woodworth,  Samuel  Syracuse  N.  Y. 

WLAJ  Waco  Electric  Supply  Co  Waco,  Texas 

WLAK  Vermont  Farm  Machine  Co. .     .     .   Bellows  Falls.  Vt. 

WLAL  Tulsa  Radio  Co  Tulsa,  Okh. 

WLAM  Morrow  Radio  Co  Springfield,  O. 

WLAN  Putnam  Hardware  Co  Houiton,  Me. 

*WLAO  Anthracite  Radio  Shop    .....    Scranton,  Pa. 

WLAP  Jordon,  W.  V  Louisville,  Ky. 

WLAQ  Shilling.  A.  E  Kalamazoo,  Mich. 

*WLAR  Mickel  Music  Co  Marshalltown,  Iowa 

WLAS  Hutchinson  Grain  Radio  Co.  Hutchinson,  Kansas 

WLAT  Bosch  Co.,  Chas.  G  Burlington,  Iowa 

WLAV  Electric  Shoo  Inc  Pensacola,  Fla. 

WLAW  New  York  Police  Dept  New  York,  N.  Y. 

WLAX  Greencastle  Community  Broadcasting  Station 

Greencastle.  Ind. 

WLAY  Northern  Commercial  Co.  of  Alaska  Fairbanks,  Alaska 

WLAZ  Hutton  &  Jones  Elect.  Co   Warren,  O. 

WLB  University  of  Minnesota  .  Minneapolis,  Minn. 

WLDO  Anthracite  Radio  Shop  Scranton,  Pa. 

WLK  Hamilton  Manufacturing  Co.         .  Indianapolis,  Ind. 

WLW  Crosley  Manufacturing  Co.  .  Cincinnati,  O. 

WMA  Arrow  Radio  Laboratories  Anderson,  Ind. 

WMAB  Radio  Supply  CD:       ...       Oklahoma  City,  Okla. 

WMAC  Page.  F.  Edward  Cazenovia,  N.  Y. 

WMAD  Atchinson  County  Mail  Rockport,  Mo. 

WMAF  Round  Hills  Radio  Corp.      .  .  Dartmouth,  Mass. 

WMAG  The  Tucker  Electric  Co.      .  .     .  Liberal,  Kansas 

WMAH  General  Supply  Co  Lincoln,  Neb. 

WMAJ  Drovers  Telegram  Co  Kansas  City.  Mo. 

WMAK  Norton  Laboratories  Lockport,  N.  Y. 

WMAL  Trenton  Hardware  Co  Trenton,  N.  J. 

WMAM  Beaumont  Radio  Equipment  Co.  Beaumont,  Tex. 

WMAN  Broad  Street  Baptist  Church  .  Columbus,  O. 

WMAP  Utility  Battery  Service  Easton,  Pa. 

WMAQ  The  Fair  Corp.  &  The  Chicago  Daily  News  Chicago,  111. 

WMAR  Waterloo  Electrical  Supply  Co.  .  Waterloo,  Iowa 

WMAT  Paramount  Radio  Corp  Duluth,  Minn. 

WMAU  Louisiana  State  Fair  Ass'n  ....  Shreveport,  La. 

WMAV  Alamaba  Polytechnic  Inst.    .  .   Auburn.  Alabama 

WMAW  Wahpeton  Electric  Co  Wahpeton,  N.  D. 

WMAX  K.  &  K.  Radio  Supply  Co.    .     .     .  Ann  Arbor,  Mich. 

WMAY  Kings  Highway  Presb.  Church  .     .        St.  Louis,  Mo. 

WMAZ  Mercer  University   Macon,  Ga. 

WMB  Auburn  Electrical  Co  Auburn,  Me. 

"WMC  Columbia  Radio  Co  Youngstown,  O. 

WMC  Commercial  Publishing  Co.  .     .     .     Memphis,  Tenn. 

WMH  Precision  Equipment  Co  Cincinnati,  Ohio 

WMU  Doubleday-Hill  Electrical  Co.  Washington,  D.  C. 

WNAB  Park  City  Daily  News     .     .     .     Bowling  Green,  Ky. 

WNAC  Shepard  Stores  Boston,  Mass. 

WNAD  Oklahoma  Radio  Eng.  Co  Norman.  Okla. 


RADIO  BROADCAST  ADVERTISER 


Why  do  you  do  it  ? 


TUNGAR  CHARClf  OVERNIGHT 


Is  your  battery  always 
fully  charged  and  fit? 

Is  it  always  toned  up  for  best  results,  whenever 
friends  happen  in — throughout  every  concert  ? 
Keep  it  at  full  strength  and  prolong  its  life — 
the  simple,  easy,  inexpensive  Tungar  way. 
Tungar — the  go-between  from  house-lighting 
circuit  to  storage  battery — attaches  wherever 
there  is  a  lamp  or  convenience  outlet. 
You  don't  have  to  move  the  battery.  Just 
connect  Tungar,  and  leave  it — -any  time,  day 
or  night. 

Tungar  is  certain,  clean,  quiet.    No  moving 
parts  to  get  out  of  order  or  make  noise. 
Good  for  the  auto    battery  too — the  same 
Tungar. 

See  one  at  any  good  electrical  store.or  write  for 
literature.    Address  Section  RB5. 

Merchandise  Department 

General  Electric  Company 

Bridgeport,  Connecticut 


Tungar  Battery  Charger.  Oper- 
ates on  Alternating  Current. 
2  Ampere  Outfits— $18.00 
5  Ampere  Outfits— $28.00 

( Prices  east  of  the  KockiesJ 
Special  attachment  for 
charging  12  or  24  cell 
"B"  Storage  Battery —$3.00 
— fits  either  size  Tungar. 


Charge  'em  at  Home,  with 

Tunga  r 


BATTERY  CHARGER 


GENERAL  ELECTRIC 


PRODUCT 

35A— 96C 


■jc  Tested  and  approved  by  Radio  Broadcast 


84 


Radio  Broadcast 


*WNAF 

*WNAG 

*WNAH 

*WNAJ 

WNAL 

WNAM 

WNAN 

WNAP 

WNAQ 

WNAR 

WNAS 

WNAT 

WNAV 

WNAW 

WNAX 

WNAY 

WNJ 

WNO 

WOAA 

WOAB 

WOAC 

WOAD 

WOAE 

WOAF 

WOAG 

WOAH 

WO  A I 

WOAJ 

WOAK 

WOAL 

WOAM 

WOAN 

WOAO 

WOAP 

WOAQ 

WOAR 

WOAS 

WOAT 

WOAU 

WOAV 

WOAW 

WOAX 

WOAY 

WOAZ 

WOC 

*WOE 

*WOH 

WO  I 

WOK 

WOO 

WOQ 

WOR 

WOS 

WOU 

WOZ 

WPA 

WPAB 

WPAC 

WPAD 

WPAF 

WPAG 

WPAH 

WPAJ 

WPAK 

WPAL 

WPAM 

*WPAN 

WPAP 

WPAQ 

WPAR 

WPAS 

WPAT 

WPAU 

WPAV 

WPAW 

WPAX 

WPAY 

WPAZ 

WPB 

*WPE 

WPG 

WPI 

*WPJ 

WPL 

WPM 

WPO 

WQAA 

WQAB 

WQAC 

WQAD 

WQAE 

WQAF 

WQAH 

WQAJ 

WQAK 

WQAL 

WQAM 

WQAN 

WQAO 


Enid  Radio  Distributing  Co  Enid,  Okla. 

Rathert  Radio  &  Elect.  Co  Cresco,  Iowa 

Wilkes-Barre  Radio  Repair  Shop        Wilkes-Barre,  Pa. 

Benson  Co  Chicago,  111. 

Rockwell,  R.  J  Omaha,  Neb. 

Ideal  Apparatus  Co  Evansville,  Ind. 

Syracuse  Radio  Tel.  Co  Syracuse,  N.  Y. 

Wittenberg  College   Springfield,  O. 

Charleston  Radio  Electric  Co.    .     .    Charleston,  S.  C. 

C.C.Rhodes  .    Butler,  Mo. 

Texas  Radio  Corp   Austin,  Texas 

Lenning  Bros.  Co   Philadelphia,  Pa. 

People's  Telep.  &  Teleg.  Co. .  .  .  Knoxville,  Tenn. 
Peninsular  Radio  Club  ....  Fort  Monroe,  Va. 
Dakota  Radio  Apparatus  Co.  Yankton,  S.  Dak. 

Ship  Owners  Radio  Service   .  .       Baltimore,  Md. 

Shotton  Radio  Manufacturing  Co.  .  .  Albany,  N.  Y. 
Wireless  Telephone  Co.  of  Hudson  County,  N.  J. 

Jersey  City,  N.  J. 

Hardy,  Dr.  Walter  Ardmore,  Okla. 

Valley  Radio  Grand  Forks,  N.  D. 

Maus  Radio  Co   Lima,  O. 

Whitall  Elect.  Co  Waterbury,  Conn. 

Medland  College  Fremont,  Neb. 

Tyler  Commercial  College  Tyler,  Tex. 

Apollo  Theatre   Belvedere,  111. 

Palmetto  Radio  Corp  Charleston,  S.  C. 

Southern  Equipment  Co. .         .     San  Antonio,  Texas 

Ervins  Electrical  Co  Parsons,  Kans. 

Collins  Hardware  Co   Frankfort,  Ky. 

William  E.  Woods  Webster  Grove,  Mo. 

Arthur  F.  Breisch  (temporary-1  day)  Bethlehem,  Pa. 
Vaughn  Conservatory  of  Music     Lawrenceburg,  Tenn. 

Lyradion  Mfg.  Co  Mishawaka,  Ind. 

Kalamazoo  College  ....  Kalamazoo,  Mich. 
Portsmouth  Radio  Ass'n      .     .     .    Portsmouth,  Va. 

Henry  P.  Lundskow  Kenosha,  Wis. 

Bailey's  Radio  Shop  ....      Middletown,  Conn. 

Boyd  Martell  Hamp  Wilmington,  Del. 

Sowder  Boiling  Piano  Company .     .      Evansville,  Ind. 

Penn.  National  Guard  Erie,  Pa. 

Woodmen  of  the  World  Omaha,  Neb. 


Franklyn  J.  Wolff 
John  M.  Wilder  .... 
Penick  Hughes  Co. 
Palmer  School  of  Chiropractic 
Buckeye  Radio  Service  Co.  . 
Hatfield  Electric  Co.  . 
Iowa  State  College 


Trenton,  N.  J. 
Birmingham.  Ala. 
Stanford,  Texas 
Davenport,  Iowa 
Akron,  Ohio 
Indianapolis,  Ind. 
Ames,  Iowa 


Pine  Bluff  Co.  .     .     .  '  .     .     .     .      Pine  Bluff,  Ark. 

Wanamaker,  John   Philadelphia,  Pa. 

Western  Radio  Co   Kansas  City,  Mo. 

Bamberger  &  Co.,  L  Newark,  N.  J. 

Missouri  State  Marketing  Bureau  Jefferson  City,  Mo. 
Metropolitan  Utilities  District   .     .         Omaha,  Neb. 

Palladium  Printing  Co  Richmond.  Ind. 

Fort  Worth  Record  ....  Fort  Worth,  Texas. 
Penn.  State  College  ....  State  College,  Pa. 
Donaldson  Radio  Co.      .     .     .  Okmulgee,  Okla. 

W.  A.  Wieboldt  &  Co   Chicago.  111. 

Peterson's  Radio  Co  Council  Bluffs,  Iowa 

Central  Radio  Co.,  Inc  Indeoendence,  Mo. 

Wisconsin  Dept.  of  Markets      .  Waupaca,  Wis. 

Doolittle  Radio  Corporation .  .  New  Haven,  Conn. 
North  Dakota  Agricultural  College.     .  N.  D. 

Superior  Radio  &  Tel.  Equipment  Co.  Columbus,  Ohio 

Auerbach  &  Guettel  Topeka,  Kans. 

Levy  Bros.  Dry  Goods  Co.   .     .     .      Houston,  Texas 

Theodore  S.  Phillips  Winchester,  Ky. 

General  Sales  &  Engr.  Co.  .      Frostburg,  Md. 

R.  A.  Ward  Beloit,  Kan. 

J.  &  M.  Electric  Co  Amsterdam,  N.  Y. 

Saint  Patrick's  Cathedral     ...       EI  Paso.  Texas 

Concordia  College  Moorhead,  Minn. 

Tinetti  &  Sons,  Paul  Laurium,  Mich. 

Radio  Installation  Co.,  Inc.  .     .        Wilmington,  Del. 

S — W  Radio  Co  Thomasville,  Ga. 

Bangor  Radio  Laboratory     ....  Bangor,  Maine 

Koch,  Dr.  John  R  Charleston,  W.  Va. 

Newspapers  Printing  Co  Pittsburgh,  Pa. 

Central  Radio  Co  Kansas  City,  Mo. 

Nushawg  Poultry  Farm  ....   New  Lebanon,  O. 

Electric  Supply  Co  Clearfield,  Pa. 

St.  Joseph's  College     ....        Philadelphia,  Pa. 

Fergus  Electric  Co  Zanesville,  O. 

Williams,  Thomas  L   Washington,  D.  C. 

United  Equipment  Co  Memphis,  Tenn. 

Horace  A.  Beele,  Jr  Parkersburg,  Pa. 

Southwest  Missouri  State  Teachers'  College 

Springfield,  Mo. 

Gish,  E.  B  Amarillo,  Texas 

Whitall  Electric  Co   Waterbury,  Conn. 

Moore  Radio  News  Station  ....  Springfield,  Vt. 

Sandusky  Register  Sandusky,  O. 

Brock-Anderson  Elect.  Eng.  Co.  .  Lexington,  Ky. 
Ann  Arbor  Times  News  ....  Ann  Arbor,  Mich. 
Appel-Higley  Electric  Co.     .  Dubuque,  Iowa 

Cole  County  Tel.  &  Tel.  Co.  .     Mattoon,  111. 

Electrical  Equipment  Co  Miami,  Fla. 

Scranton  Times  Scranton,  Pa. 

Calvary  Baptist  Church  .     .     .        New  York,  N.  Y. 


WQAQ  West  Texas  Radio  Co  Abilene,  Texas 

WQAR  Press  Publishing  Co  Muncie.  Ind 

WQAS  Prince- Walter  Co  Lowell,  Mass 

WQAT  Radio  Equipment  Corp.  .     .     .       Westhampton,  Va! 

WQAV  Huntington  &  Guerry,  Inc.   .     .     .     Greenville.  S  C 

WQAW  Catholic  University  of  America         Washington  D  C 

WQAX  S— W  Radio  Co.,  J.  R.  Shumate,  Jr.    Thomasville,  Ga 

WQAY  Gaston  Music  &  Furniture  Co.  .     .     .  Hastings  Neb 

WQX  Walter  A.  Kushe  Chicfgo,  111! 

WRAA  Rice  Institute   Houston,  Tex 

WRAB  Savannah  Board  of  Public  Education   .  Savannah,  Ga 

WRAC  State  Normal  School  Mayville  N  D 

WRAD  Taylor  Radio  Shop  Marion,  Kan! 

WRAH  Stanley  N.  Read  Providence,  R.  I. 

WRAJ  Pickering  Co..  M.  H  Pittsburgh,  Pa. 

WRAM  Lombard  College  Galesburg,  111. 

WRAN  Black  Hawk  Electric  Company  .  Waterloo,  Iowa 

WRAO  Radio  Service  Co  St.  Louis,  Mo. 

WRAR  Jacob  C.  Thomas  David  City,  Neb! 

WRAU  Amarillo  Daily  News  Amarillo  Tex 

WRAV  Antioch  College  Yellow  Springs,  O. 

WRAY  Radio  Sales  Corp  Scranton,  Pa 

WRK  Doran  Brothers  Electrical  Co.    .     .     .     Hamilton  O 

WRL  Union  College  Schenectady,  N.  Y. 

WRM  University  of  Illinois  Urbana,  Illinois 

WRP  Federal  Institute  of  Radio  Telegraphy     Camden,  N.  J. 

WRR  City  of  Dallas  Dallas,  Tex. 

WRW  Tarrytown  Radio  Research  Laboratory 

Tarrytown,  N.  Y. 

WSAA  Sprague,  B.  S.  Elect.  Co  Marietta,  O. 

WSAB  Southeast  Missouri  State  Teachers'  College 

Cape  Girardeau,  Mo. 

WSAC  Clemson  Agricultural  College      Clemson  College,  S.  C. 

WSAH  Leonard,  A.  G.,  Jr  Chicago,  111. 

WSAJ  Grove  City  College  Grove  City,  Pa. 

WSAL  Franklin  Elect.  Co  Brookville,  Ind. 

WSAS  State  of  Nebraska  Lincoln,  Neb. 

WSAT  The  Plainview  Electric  Co.  .     .         Plainview,  Texas 

WSAV  Radio  Construction  Co  Houston,  Texas 

WSB  Atlanta  Journal     .     .     .     .     .     .     .      Atlanta,  Ga. 

WSL  J.  &  M.  Electric  Co.  Utica,  N.  Y. 

*WSN  Ship  Owners  Radio  Service  ....      Norfolk,  Va. 

WSV  Hunter,  L.  M.  &  G.  L.  Carrington  .    Little  Rock,  Ark. 

*WSX  Erie  Radio  Co  Erie.  Pa. 

WSY  Alabama  Power  Co  Birmingham,  Ala. 

WSZ  Marshall-Gerkin  Co  Toledo,  O. 

WTAC  Penn.  Traffic  Co   Johnstown,  Pa. 

WTAS  Carpenter,  George  D.  Elgin,  111. 

WTAU  Ruegy  Battery  &  Electric  Co.    .     .     Tecumseh,  Neb. 

WTAW  Agricultural  &  Mechanical  College  of  Texas 

College  Station,  Texas 

WTG  Kansas  State  Agricultural  College  .   Manhattan,  Kan. 

WTK  Paris  Radio  Electric  Co  Paris,  Tex. 

WTP  McBridge,  George  M  Bay  City,  Mich. 

WWAC  Sanger  Bros   Waco,  Texas 

WWAD  Wright  &  Wright,  Inc.     .     .     .        Philadelphia,  Pa. 

WWAH  General  Supply  Co  Lincoln,  Neb. 

WWAX  Worman  Bros  Laredo,  Tex. 

WWAY  Marigold  Gardens  Chicago,  111. 

WWB  Daily  News  Printing  Co  Canton,  O. 

WWI  Ford  Motor  Co  Dearborn,  Mich. 

WWJ  Detroit  News   Detroit,  Mich. 

WWL  Loyola  University      ....        New  Orleans,  La. 

WWT  McCarthy  Bros.  &  Ford  Buffalo,  N.  Y. 

WWZ  Wanamaker,  John  New  York,  N.  Y. 

CFAC  Radio  Corp.  of  Calgary,  Ltd.,    .     .     Calgary,  Alberta 

CFCA  Star  Pub.  and  Printing  Co.  .         .    Toronto,  Ontario 

CFCB  Marconi  Wireless  Telegraph  Co.  of  Canada,  Ltd. 

Vancouver,  B.  C. 

CFCD  Canadian  Westinghouse  Co.,  Ltd.    Winnipeg,  Manitoba 

CFCE  Marconi  W.  T.  Co.  of  Canada   .     .         Halifax,  N.  S. 

CFCF  Marconi  W.  T.  Co.  of  Canada,  Ltd.   Montreal,  Quebec 

CFCH  Abitibi  Power  and  Paper  Co.,  Ltd. 

Iroquois  Falls,  Ontario 

CFCI  Motor  Products  Corp.     .     .     .  Walkersville,  Ontario 

CFCN  W.  W.  Grant  Radio,  Ltd.     .     .     .     Calgary,  Alberta 

CFCX  The  London  Advertiser   ....     London,  Ontario 

CFPC  International  Radio  Development  Co. 

Fort  Frances,  Ontario 

CFTC  The  Bell  Telephone  Co.  of  Canada  .    Toronto,  Ontario 

CFUC  University  of  Montreal    ....  Montreal,  Quebec 

CFVC  Roy  Russell  Brown  Courtenay,  British  Columbia 

CFYC  Victor  Wentworth  Odium     .     .     .    Vancouver,  B.  C. 

CFZC  Canadian  Westinghouse  Co.,  Ltd.   .  Montreal,  Quebec 

CHAC  Radio  Engineers,  Ltd.  Nova  Scotia,  Halifax 

CHBC  The  Albertan  Publishing  Co.     .     .    Calgary,  Alberta 

CHCA  Radio  Corp.  of  Vancouver,  Ltd. .     .    Vancouver,  B.  C. 

CHCB  Marconi  W.  T.  Co.  of  Canada,  Ltd.     Toronto,  Ontario 

CHCC  Canadian  Westinghouse  Co.,  Ltd.     Edmonton,  Alberta 

CHCF  Radio  Corp.  of  Winnipeg,  Ltd.  .    Winnipeg,  Manitoba 

CHCQ  The  Western  Radio  Co.,  Ltd.     .     .     Calgary,  Alberta 

CHCS  London  Radio  Shoppe     ....     London,  Ontario 

CHCX  B.  L.  Silver  Montreal,  Quebec 

CHCZ  The  Globe  Printing  Co  Toronto,  Ontario 

CHFC  John  Millen  &  Sons,  Ltd.     .     .     .    Toronto,  Ontario 

CHIC  Canadian  Westinghouse  Co.,  Ltd.     Hamilton,  Ontario 

CHOC  Canadian  Westinghouse  Co.,  Ltd.       Vancouver,  B.  C. 

CHVC  Metropolitan  Motors,  Ltd.   .         .    Toronto,  Ontario 

CHXC  J.  R.  Booth,  Jr  Ottawa,  Ontario 

CHYC  Northern  Electric  Co  Montreal,  Quebec 

CJBC  Dupuis  Freres   Montreal,  Quebec 


RADIO  BROADCAST  ADVERTISER 


3  Letters/  and  they  will 
be  interesting  to  every 


HciMtOK  Motok  C  'ar  Compaxyof^YI 


November  23rd,  1922 

Acme  Apparatus  Company 
Cambridge,  Mass. 

Gentlemen:: — 

It  will  possibly  be  of  interest  to  you  to 
know  that  with  the  aid  of  your  radio  Frequency  Trans- 
formers R2,  R3  and  R4,  I  have  built  an  ideal  set.  This 
set  brings  in  PWX,  Havana,  as  clear  as  a  bell  any  time 
that  I  care  to  hear  him.  I  have  also  reached  other 
stations  that  I  never  knew  existed.  Last  night  I 
hooked  up  3  Transformers  in  place  of  yours,  and 
with  the  stations  that  I  received  there  was  enough 
howls  and  yells  to  make  one  think  that  all  Hell  was  let 
loose  at  once,  so  put  the  old  Acme's  back  and  the  loud 
speaker  started  to  give  out  some  real  music.  This  set 
has  given  such  satisfaction  that  I  simply  couldn't  re- 
frain from  writing  you  to  let  you  know  that  you  have 
satisfied  at  least  one  Radio  Bug.  However,  I  might 
add  that  I  am  using  a  loop  antenna  and  my  tuner  con- 
sists of  only  2  Variable  condensers,  one  43  plate  and 
one  3  plate  hooked  right  across  the  loop  outlet. 

Please  do  not  think  that  this  is  the  first 
set  I  have  ever  seen  and  that  my  enthusiasm  is  running 
away  with  me.  I  have  owned  a  ....  a  step 
and  a  .  .  .  .  and  have  also  built  numerous  other 
sets,  but  this  Acme  Radio  Frequency  Transformer 
sure  has  the  world  licked. 

Very  truly  yours, 
Hudson  Motor  Car  Company  of  N.  Y.,  Inc. 


Service  Manager 


YOU  can  purchase  all  Acme  Trans- 
formers at  radio  stores.  If  your  dealer 
does  not 'carry  them,  we  will  see  that 
you  are  taken  care  of.  Leaflets  describ- 
ing hook-ups  for  various  Acme  Trans- 
formers will  be  sent  on  request. 

THE  ACME  APPARATUS  COMPANY 

(Pioneer  transformer  and  radio 
engineers  and  manufacturers.) 

CAMBRIDGE,  MASS.,  U.   S.  A. 
New  York  1270  Broadway 

Chicago  184  W.  Washington  Street 


ACME 


* 


radio  user. 


TlCANM''UK>IEII£K\lil«Kx«IX»:llserMulVK\CTIIKEKS 

u'u'V^io™.  CAMIIHIlfCiK  XJ.MA.Hb..U.!kA. 

Mr.  John  M.  Craig  December  7th,  1922 

510  St.  Marks  Avenue 
Brooklyn,  N.  Y. 
Dear  Sir: — 

We  wish  to  thank  you  for  your  letter  of 
November  23rd  and  would  like  to  know  if  you  would 
be  willing  to  allow  us  to  use  this  as  a  testimonial  either 
with  or  without  vour  name. 

We  worked  for  practically  nine  months 
before  putting  a  radio  frequency  amplifying  trans- 
former on  the  market  and  it  is  exceedingly  gratifying 
to  receive  such  letters  as  yours  as  a  reward  for  this 
endeavor. 

Yours  very  truly, 
ACME  APPARATUS  COMPANY 


Per  Chief  Engineer 


Ilrnsox  Motor  <  Are  <  Compact  of  Alt; 

IHDSIIX  A>  l>  I  <*«.!  : V  MOTOR  «  .VK** 

1428  HeuraRnAVKa 


Diluvial 


Mr.  G.  E.  M.  Bertram  December  8th,  1922 

186  Massachusetts  Ave. , 
Cambridge,  Mass. 

Dear  Sir: — 

Your  letter  of  the  7th  instant  came  to 
hand  this  morning,  and  in  reply  would  say  that  you 
are  at  liberty  to  use  ray  letter  of  November  23rd,  in 
any  way  you  desire,  with  or  without  my  name.  I 
might  add  that  I  know  of  four  sets  copied  from  mine 
that  are  giving  results  equal  to  mine. 

On  Wednesday  evening  I  had  a  trans- 
mission engineer  from  the  New  York  Telephone 
Company  out  to  my  home  and  believe  me  he  was  the 
most  surprised  man  I  have  seen  in  some  time.  With- 
out having  ever  seen  mv  set,  in  twenty  minutes  he 
tuned  in  PWX,  WOC,  WBAP,  WSB  and  several  near 
stations.  What  pleased  him  especially  was  that  he 
could  tune  in  the  200  meter  stations  as  well  as  the  400 
meter  boys. 

Very  truly  yours, 
Hudson  Motor  Car  Company  of  N.  Y.,  Inc. 


JMC:N 

510  St.  Marks  Avenue 
Brooklyn,  N.  Y. 


Service  Manager 


for  amplification 


•fa  Tested  and  approved  by  Radio  Broadcast  ^ 


86 


Radio  Broadcast 


CJCA  The  Edmonton  Journal,  Ltd.,     .      Edmonton,  Alberta  CJSC 

CJCB  James  Gordon  Bennett           Nelson,  British  Columbia  CKAC 

CJCD  T.  Eaton  Co.,  Ltd  Toronto,  Ontario  CK.CB 

CJCE  Vancouver  Sun  Radiotelephones,  Ltd.  Vancouver,  B.  C.  CKCD 

CJCF  News  Record,  Ltd  Kitchener,  Ontario  CKCE 

CJCG  Manitoba  Free  Press  Co.,  Ltd.  .    Winnipeg,  Manitoba  CKCK 

CJCH  The  United  Farmers  of  Ontario           Toronto,  Ontario  CKCR 

CJCI  McLean,  Holt  &  Co.,  Ltd.      St.  John,  New  Brunswick  CKCS 

CJCN  Simons  Agnew  &  Co  Toronto,  Ontario  CKCZ 

CJCS  Eastern  Tel.  and  Tel.  Co.,  Ltd.  .   Halifax,  Nova  Scotia  _CKKC 

CJCY  Edmund  Taylor  Calgary,  Alberta  CKOG-r> 

CJGC  London  Free  Press  Printing  Co.,  Ltd.  >tCKQG 

London,  Ontario  CKZCt" 

CJNC  Tribune  Newspaper  Co.,  Ltd.        Winnipeg,  Manitoba  • 


The  Evening  Telegram    ....    Toronto,  Ontario 

La  Presse  Publishing  Co  Montreal,  Quebec 

T.  Eaton  Co.,  Ltd  Winnipeg,  Manitoba 

Vancouver  Daily  Province  .  Vancouver,  B.  C. 
Canadian  Independent  Tel.  Co.,  Ltd.  Toronto,  Ontario 
Leader  Publishing  Co.,  Ltd.,  Regina,  Saskatchewan 
Jones  Electric  Radio  Co.  St.  John,  New  Brunswick 
The  Bell  Telephone  Co.  of  Canada  .  Montreal,  Quebec 
Canadian  Westinghouse  Co.,  Ltd.  .  Toronto,  Ontario 
Radio  Equipment  and  Supply  Co.  .  Toronto,  Ontario 
The  Wentworth  Radio  Supply  Co.  Hamilton,  Ontario 
Radio  Supply  Co.  of  London  .     London.  Ontario 

Salton  Radio  Engineering  Co.    .    Winnipeg,  Manitoba 


THE^GKID 

(Continued  from  page  79) 


tion  seldom  desirable  in  receiving  other  than  continuous 
wave  signals. 

However,  as  the  grid  or  secondary  circuit  is  of  course 
in  resonance  with  the  primary,  the  set  is  theoretically  more 
efficient  when  the  plate  circuit  is  likewise  in  perfect  tune 
with  the  received  wave,  i.e.,  each  and  every  circuit  is 
cooperating  to  make  the  most  of  the  energy  picked  up  by 
the  antenna.  As  before  explained,  it  is  impracticable  to 
realize  this  condition  often  (except  in  super-regeneration) 
due  to  the  circuit  falling  into  an  oscillating  state;  but  the 
experienced  operator  effects  a  compromise  by  slightly 
lowering  the  filament,  and  continuing  to  tune  the  plate 
circuit  toward  resonance.  A  happy  medium  resulting 
in  the  loudest  signals  may  be  thus  achieved,  when  the 
plate  circuit  is  almost  resonant,  and  the  detector  filament 
lowered  just  enough  to  prevent  oscillations  without  impairing 
the  efficiency  of  the  tube.  Needless  to  say,  the  life  of  the 
bulb  is  prolonged  by  this  finesse. 

The  phenomena  of  tickler  and  variometer  regeneration 
were  explained  in  detail  in  the  December  Grid. 

Regeneration  in  the  De  Forest  ultra-audion  circuit  can 
be  controlled,  but  to  a  lesser  degree  than  is  possible  in 
variometer  and  tickler  circuits.  Control  is  principally 
effected  by  the  coupling  condenser  between  the  plate  and 
filament.  In  many  cases  the  oscillations  may  be  rendered 
less  critical  by  varying  the  grid  leak,  grid  condenser,  fila- 
ment rheostat  or  a  B  battery  potentiometer. 

Whatever  advantage  exists  in  a  circuit  combining  both 
tickler  and  variometer  regeneration  is  counteracted  by 
the  critical  and  unstable  operation.  However,  some  ama- 
teurs, familiar  with  the  idiosyncrasies  of  the  circuit,  have 
experienced  phenomenal  results  using  a  three  coil  (primary, 
secondary  and  tickler)  honeycomb  set,  with  variometers 
in  the  grid  and  plate  circuits. 

A  very  effective  combination  of  tuned  plate  and  tickler 
feed-back  can  be  easily  secured  by  shunting  the  tickler  coil 
(a  half  dozen  or  so  turns  under  the  normal  size)  by  a 
twenty-three  plate  variable  condenser. 

Artificial  Strays 

We  are  troubled  here  with  a  Cotter  ell  dust  precipitating  plant 
at  the  smeller,  and  so  far  it  has  been  impossible  to  use  a  re- 
ceiver on  account  of  the  Cotterell  making  more  noise  than  the 
incoming  signals.  However,  I  think,  perhaps,  that  a  radio- 
frequency  outfit  may  work  through  this.  What  are  your 
ideas  ? 

— W.  H.  M.,  Miami,  Arizona. 


DUST  precipitating  arrangements,  as  well  as  those  for 
the  elimination  of  heavy  factory  smoke,  operate  on 
the  principle  of  the  electrical  attraction  and  repul- 
sion of  charged  conductors  on  small  particles,  such  as  dust 
and  carbon  (smoke).  Many  achieve  this  effect  by  means  of 
high  potentials  which,  continually  breaking  down  in  the 
process  of  charging  the  microscopic  matter,  set  up  radio 
waves.  Nearby  X-ray  and  high-frequency  apparatus 
causes  similar  QRM  (interference),  as  well  as  do  radio- 
frequency  machines  for  the  cultivation  of  plants  and  gar- 
dens. These  last  consist  primarily  of  an  antenna  sus- 
pended over  a  ground  (the  area  under  cultivation)  and 
create  such  an  atmospheric  disturbance  that  they  have 
attracted  government  attention.  It  is  contended  by  some 
that  the  agricultural  enterprise  is  no  other  than  a  radio 
station  transmitting  without  a  license,  and  should  be  pros- 
ecuted as  such! 

Radio-frequency  amplification  will  doubtless  be  helpful 
in  almost  every  case,  and  in  many  instances  will  eliminate 
such  artificial  static. 

If  the  disturbance  is  of  audio  frequency,  due  to  powerful 
induction,  and  inductively  coupled  receiver  (one  having 
primary  and  secondary,  with  no  metallic  circuit  between 
the  audion  and  the  antenna  system)  will  help  matters,  and 
radio-frequency  amplification,  which  is  nothing  more  than 
additional  couplers,  will  silence  the  last  undesired  crash. 

If  the  interference  is  in  the  form  of  a  wireless  wave,  the 
solution  is  more  difficult,  and  next  to  impossible  when  the 
predominant  wave  of  the  interfering  signal  is  that  which 
it  is  desired  to  receive.  There  is  generally  a  certain  fre- 
quency (or  wave)  in  all  radio  oscillations  which  carries  most 
of  the  power.  However,  due  to  broadness  of  the  wave 
(or  proximity  of  the  station,  in  which  case  oscillations  are 
forced  on  almost  any  frequency)  the  signals,  though  loudest 
at  the  resonant  or  predominant  point,  will  be  heard  on  more 
than  one  degree  of  the  tuning  scale.  This  resonant  point 
may  be  determined  by  merely  tuning  over  the  range  of  the 
set,  and  noting  where  the  signals  are  of  the  greatest  inten- 
sity. If  this  wavelength  is  other  than  that  which  it  is  de- 
sired to  receive,  radio-frequency  amplification  will  help 
matters,  each  step  acting  as  a  filter,  passing  and  amplifying 
the  genuine  signal,  but  descriminating  against  the  pira- 
teering  stray. 

Engineers  might  consider  this  matter,  and  design  dust 
precipitating  and  similar  apparatus,  so  that  the  emitted 
wave  is  predominantly  of  a  non-interfering  frequency. 

The  wireless  world  is  beginning  to  appreciate  the  possi- 
bilities of  radio  frequency! 


Paul  Godley  on  ''Choosing  Your  Regenerative  Circuit" 


The  Search  for  a  Telephone  as  Sensitive  as  the  Ear 

f      Operating  a  Loud  Speaker  on  One  Tube, 

Without  Batteries 

Radio  in  Summer  Camps 

The  Best  Battery  Connections 
for  the  Set  You  Use 


All  Boy  Scouts,  Attention! 
Learning  the  Code 


25  Cents 

Published  by 


DOUBLEDAY,  PAGE  &  CO. 


Garden  City,  N.  Y. 


the  standard  tube  for  all  makes  of  receiving  sets 


Mutual  Conductance 

The  Correct  Rating  for  Vacuum  Tubes 

Gas  Engines  are  rated  by  their  horsepower — Electric  Gen- 
erators are  rated  by  their  watt  or  kilowatt  output — Mazda 
Lamps  are  rated  by  their  candle-power.  All  of  these  factors 
actually  express  the  efficiency  of  the  article  for  the  purpose 
intended.  ■ 

In  the  past  vacuum  tubes  have  been  known  merely  as 
Detectors  and  Amplifiers.  These  terms  indicated  only  the 
use  for  which  the  tube  was  designed,  but  in  no  way  expressed 
its  efficiency  for  either  of  these  purposes.  Though  little  known 
to  the  general  public,  there  is  a  factoi — MUTUAL  CON- 
DUCTANCE— which  adequately  and  accurately  expresses 
the  efficiency  of  vacuum  tubes.  The  new  Cunningham 
C-301-A  has  the  highest  value  of  mutual  conductance  ever 
obtained  in  a  receiving  tube,  and  it  is  this  factor  that  is 
responsible  for  its  superior  operation  as  an  Amplifier. 
Write  for  Bulletin  1  -B  explaining  the  uses  and  advantages  of  the  term  Mutual  Conductance 
as  the  correct  rating  for  Vacuum  Tubes 

Cunningham  C-301-A  Improved  Amplifier  Now  $6.50 

Filament  Current  l/i  Amp.    Mutual  Conductance — 600  micrombos  at  100  volts  plate  and 

6  volts  neg.  grid  potential 

Patent  Notice: 

Cunningham  tubes  are  cover- 
ed by  patents  dated  1 1-7-05, 
1-15-07,  2-18-08,  and  others 
issued  and  pending.  Licensed 
for  amateur,  experimental  and 
entertainment  use  in  radio  Home  Office: 
communication.  Any  other  248  First  Street 
use  will  be  an  infringement.         San  Francisco,  Calif 


For  the  assistance  of  the  public,  in  obtaining  true  musical 
quality  and  actual  reproduction  in  broadcast  reception,  this 
company  will,  from  time  to  time,  issue  Service  Bulletins 
explaining  in  a  clear  and  simple  manner  the  most  important 
technical  features  that  must  be  observed  in  the  selection  and 
operation  of  radio  apparatus. 

Cunningham  Service  Bulletin 
No.  1  explains  the  use  of  the  fac- 
tor mutual  conductance  as  the 
standard  rating  for  vacuum 
tubes.  The  information  it  con- 
tains should  be  thoroughly  known 
to  every  owner  of  a  radio  set  who 
is  interested  in  obtaining  max- 
imum efficiency  with  a  given 
number  of  vacuum  tubes.  This 
bulletin  will  be  mailed  to  you, 
free  of  charge,  upon  request. 


The  trade  mark  GE  is  the 
guarantee  of  these  quality 
tubes.  Each  tube  is  built 
to  most  rigid  specifications. 


Eastern  Representative: 
154  West  Lake  Street 
Chicago,  Illinois 


RADIO  BROADCAST  ADVERTISER, 


^nflSlI  ^\  "VTLW  broadcasting  station 

-gHuobb^  crosley 


THE  HEIGHT  OF  EFFICIENCY 

Crosley  Model  X,  Price,  $55.  *K 

Clearly,  distinctly,  as  though  given  in  the  same  room,  messages  from  WLW  Broadcasting  Station, 
Crosley  Mfg.  Co.,  Cincinnati,  are  heard  in  all  parts  of  America  if  a  Crosley  Model  X — a  four  tube 
radio  frequency  set — is  used.  This  remarkable  instrument,  very  easy  to  tune,  simple  and  beautiful  in 
construction,  has  repeatedly  brought  in  messages  over  4900  miles  away. 

Other  Crosley  Models,  like  the  Model  VIII,  three  tube  set — price  £48,  and  the  Model  VI,  two  tube  set 
— price  $28,  have  given  exceptional  results  to  thousands  of  satisfied  users  everywhere. 

Write  For  Catalogue  Showing  Complete  Crosley  Line. 
For  Sale  By  Best  Dealers  Everywhere 

Besides  a  complete  assortment  of  receivers;  Crosley 
manufactures  parts  for  replacement  or  home  con- 
struction. 

Jobbers  and  Dealers  Will  be  Interested  in  the  Crosley 
Proposition. 

New  York  Office:  Boston  Office: 

C.  B.  COOPER,  B.  H.  SMITH, 

1803  Tribune  Bldg.,  154  Nassau  St.      929  Blue  Hill  Ave.,  Dorchester 


Chicago  Office: 
R.  A.  STEMM,  Mgr. 
1311  Steger  Bldg.,  28  E.  Jackson  Blvd. 


CROSLEY  MANUFACTURING  COMPANY 


620  ALFRED  ST. 


CINCINNATI,  OHIO 


ACE  Model  V 

$20  * 

Formerly  known  as 
CROSLEY  MODEL  VC 

This  one  tube  receiver  is  astounding  the  radio  world  with  its  wonderful  achievements.    Stations  more 

than  iooo  miles  away  are  being  regularly  copied  on  this  set.    In  comparison  to  its  price,  there  is  no 

receiver  on  the  market  to-day  to  equal  it  in  performance. 

Because  of  its  size  and  price  the  Ace  Model  V  is  a  great  summer  seller. 

Licensed  under  Armstrong  U.  S.  Patent  No.  1,113,149. 

Live  Jobbers  and  Dealers  are  eagerly  taking  advantage  of  the  sales  this  instrument  and  the  rest  of 
the  Precision  instruments  and  parts  bring  them. 

Free  Catalogue  on  Request 

THE  PRECISION  EQUIPMENT  CO. 

^OWel  Crosley  Jr.Tresideni 

62  O  GILBERT  AVE.  CINCINNATI,  OHIO 


Remarkable 
Regenerative 
Receivers 


■jr  Tested  and  approved  by  Radio  Broadcast  if 


Radio  Broadcast 


ARTHUR  H.  LYNCH,  Editor 


CONTENTS  FOR  JUNE,  1923 

Not  a  Soul  Ahoard — Controlled  by  Radio     -    --    --    --    --    --    --    --    --  Frontispiece 

THE  MARCH  OF  RADIO.-   -  ------   9I 

RADIO  IN  SUMMER  CAMPS                                                                     Elon  Jessup  102 

OPERATING  A  LOUD  SPEAKER  ON  ONE  TUBE  WITHOUT  BATTERIES 

Walter  Van  B.  Roberts  108 

A  STORMY  P.  M.  AT  ALICE'S-   --------------     Willard  Wilson  112 

Drawings  by  Thomas  E.  Monroe 

LEARNING  THE  CODE    ----------------    William  Harris,  Jr.  114 

IS  SHORT-WAVE  RELAYING  A  STEP  TOWARD  NATIONAL  BROADCASTING 

STATIONS?   W.  W.  Rodgers  119 

THE  BEST  BATTERY  CONNECTIONS  FOR  THE  SET  YOU  USE 

Edward  Lindley  Bowles  123 

A  MAN  WHO  BUILT  A  SET  HE  HAS  NEVER  SEEN     -----     Alfred  M.  Caddell  128 

A  LOOP  RECEIVER  IN  THE  TROPICS     ---------   Charles  T.  Whitefield  133 

WITH  THE  BROADCASTERS    ------------   135 

PROTECTING  YOUR  INVENTION    -----------      Roger  Sherman  Hoar  136 

THE  SEARCH  FOR  A  TELEPHONE  AS  SENSITIVE  AS  THE  EAR       George  B.  Crouse  142 

CONCERTS  FOR  ALL  IN  A  VETERANS'  HOSPITAL-   -   -   -   -   -  J.  Townsend  Bradley  147 

ADVENTURES  ON  AN  AMERICAN  YACHT  IN  MEXICO  A.  Henry  149 

Drawings  by  Thomas  E.  Monroe 

CHOOSING  YOUR  REGENERATIVE  CIRCUIT  .-   -   -   -   -  Paul  F.  Godley  154 

INTERNATIONAL  LAW  AND  THE  SEA-GOING  TELEGRAPHER 

Claude  Cathcart  Levin  159 

SOLDERING  YOUR  OWN  -  -   -  -   -    W.  S.  Standiford  161 

THE  BROADCAST  RECEIVING  CONTEST— RULES  AND  PRIZES  -   -    -  164 

A  BIT  ABOUT  BOOKS  -   -   -   -   -  -   ^5 

ALL  BOY  SCOUTS,  ATTENTION!-    -    -    -    -  -    -    -    -    -   166 

NEW  WAVELENGTHS  FOR  CLASS  B  STATIONS  ------  167 

ADDITIONAL  BROADCASTING  STATIONS  IN  THE  UNITED  STATES  -------  168 

THE  GRID— QUESTIONS  AND  ANSWERS     -----------------  170 

NEW  EQUIPMENT   ------  -   -   -   -  i76 

Copyright,  1923,  by  Doubleday,  Page  &  Co.   All  rights  reserved 
TERMS:  $3.00  a  year;  single  copies  25  cents 
F.  N.  Doubleday,  Pres.  Arthur  W.  Page,  Vice-Pres.  Nelson  Doubleday,  Vice-Pres. 

Russell  Doubleday,  Sec'y.  S.  A.  Everitt,  Treas.  John  J.  Hessian,  Asst.  Treas. 

DOUBLEDAY,  PAGE  &  CO. 

The  World's  Work     Country  Life      The  Garden  Magazine     Short  Stories     Educational  Review 

CHICAGO:  People's  Gas  Bldg.                             GARDEN  CITY,  N.  Y.                         NEW  YORK:  120  W.  32nd  Street 
BOSTON:  Tremont  Bldg.                 LOS  ANGELES:  Van  Nuys  Bldg. 


RADIO  BROADCAST  ADVERTISER 


Don't  Tear  1923  in  Half 


How  a  loop  and  Acme  for  amplification  make  radio 
a  pleasure  the  whole  year  round 


IS  YOUR  radio  set  good  for  just  about  six 
months  of  the  year?  Do  you  want  to  find  a 
way  to  get  distant  stations  clearly  and  dis  inctly 
the  entire  year;  to  get  these  stations  without  the 
usual  amount  of  interference  from  government 
and  other  spark  transmitting  stations,  from  your 
neighbor's  radiating  receiving  set,  or  from  our  old 
foe  "summer  static"?    Then  here's  a  way. 

Use  a  loop  and  Acme  for 
amplification 

Tear  down  your  antenna,  put  on  a  loop  and  use 
Acme  for  amplification  (preferably  with  dry  battery 
tubes)  and  reduce  your  interference  troubles  to 
a  minimum.  By  using  Acme  for  amplification  you 
get  more  than  mere  amplification — you  get  dis- 
tance and  volume  without  distortion.  There's  the 
Acme  Radio  Frequency  Amplifying  Transformers 
(R-l-2-3-4)  for  distance  and  the  Acme  Audio  Fre- 
quency Amplifying  Trans- 
former A-2  for  volume,  and 
the  Acme  Kleerspeaker  for 
clearness.  Use  Acme  in  the 
set  you  build  and  look  for  it 
in  the  set  you  buy.  You  can 
buy  this  standard  Acme  Ap- 
paratus at  any  radio  or  elec- 
trical store. 

A  special  booklet  has  just 
been  prepared  explaining  ex- 
actly how  to  avoid  interfer- 
ence and  to  secure  distant 
stations  clearly  and  distinct- 


ly. The  booklet  includes  wiring  diagrams  and 
other  serviceable  information.  It  will  be  sent 
postpaid  anywhere  in  the  United  States,  Canada 
or  Mexico  on  receipt  of  ten  cents  or  its  equivalent 
in  American  money.  This  small  charge  is  made 
in  order  to  be  certain  that  the  booklet  is  placed  in 
the  hands  of  radio  owners  and  experimenters  and 
that  it  will  not  be  wasted  upon  mere  curiosity 
seekers.    The  coupon  is  for  your  convenience. 

ACME  APPARATUS  COMPANY 

(Pioneer  radio  engineers  and 
manufacturers) 

Cambridge  Mass.,  U.  S.  A. 

SALES  OFFICES  IN  PRINCIPAL  CITIES 
New  York  Chicago  Cleveland 

1370  Broadway  184  W.  Washington  St.  3707  Euclid  Ave. 
Kansas  City  San  Francisco 

208  Baltimore  Bldgr.  207  Minna  St. 


ACME  APPARATUS  CO. 
Cambridge,  Mass.,  U.  S.  A. 

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NOT  A  SOUL  ABOARD — CONTROLLED  BY  RADIO 
The  old  U.  S.  S.  Iowa,  picked  as  the  moving  target,  in  the  recent  maneuvers  off 
Panama,  for  the  big  guns  of  the  super-dreadnought,  Mississippi.  She  was  guided 
on  her  final  trip  by  a  delicate  system  of  radio  controls.  Early  in  the  "battle," 
this  apparatus  aboard  the  Iowa  was  put  out  of  commission,  and  she  was  sent  to  the 
bottom  in  quick  time,  it  being  no  longer  possible  for  her  to  evade  the  enemy  fire 


RADIO 
BROADCAST 

Vol.  3    No.  2  \^  '^^eL  ^Une'  1923 

The  March  of  Radio 

OUTDOOR  EXPERIMENTING  IN  VACATION-TIME 


"       "^VERY  man  is  endowed  to  a  greater 

Mor  less  degree  with  the  spirit  of  re- 
search— the  spirit  which  urges  him  to 
investigate,  for  himself,  the  region  of 

 "*   the  unknown.    It  is  probably  this 

desire  to  know  new  things,  to  investigate  fields 
as  yet  unexplored,  more  than  any  other  of  his 
characteristics  which  has  differentiated  man 
from  the  other  animals.  None  of  the  higher 
anthropoids  has  been  known  to  show  curiosity 
about  the  use  of  iron  ore,  for  example:  to  him 
it  remains  the  same  as  any  other  dirt;  but  to 
man,  who  noticed  its  changes  when  heated  in  a 
fire,  it  became  the  source  of  steel,  the  basis  of 
our  industrial  life. 

Whereas  the  research  accomplishments  of 
but  few  men  are  written  upon  the  pages  of 
progress,  it  is  undoubtedly  true  that  any  normal 
man  from  childhood  up  likes  to  "see  what  will 
happen"  as  a  result  of  conditions  he  controls. 
For  most  of  us,  however,  research  must  occupy 
a  minor  role,  as  the  routine  accomplishment 
of  the  ordinary  prosaic  tasks  must  necessarily 
use  most  of  our  time  and  energy.  To  him  who 
is  more  than  ordinarily  gifted  with  the  spirit 
of  investigation  the  life  of  the  real  research 
worker — who  year  after  year  as  his  sole  occupa- 
tion pursues  the  unknown — must  seem  like  one 
long  journey  through  Elysian  fields. 

The  office  or  factory  tasks  seem  very  un- 
attractive when  compared  to  this  work  carried 
out  in  the  spirit  of  "1  must  find  out."  Al- 
though the  large  industrial  companies  are  very 


rapidly  expanding  their  research  staffs  and 
laboratories,  there  can  never  be  more  than  a 
very  small  percentage  of  us  actually  engaged  in 
research  work  as  a  profession.  The  labor  of 
the  researcher  must  be  supported  by  the  more 
matter-of-fact  jobs  of  the  factory  and  office 
worker.  Most  of  the  research  men's  labors 
bring  forth  nothing  new  of  material  value,  so 
that  it. is  a  foregone  conclusion  that  most  of  us 
must  be  content  to  perform  our  routine  tasks  ef- 
ficiently to  support  the  researcher,  and  we  must 
satisfy  our  investigating  spirit  by  imaginative 
trips  or  by  reading  of  the  work  accomplished 
by  others. 

The  general  interest  in  radio  has  brought 
thousands  of  us  closer  to  a  new  and  unexplored 
field  than  we  had  thought  possible,  and  in 
this  field  we  can  labor  to  our  heart's  content, 
for  the  cost  of  the  apparatus  is  generally 
within  our  means  and  the  corner  of  the 
living  room  suffices  for  a  laboratory.  That 
radio  does  serve  as  an  outlet  for  the  "  I'd  like 
to  know"  spirit  of  thousands  can  be  judged  by 
the  conversation  of  young  and  old  as  they 
compare  notes  on  their  way  to  and  from  work. 
Hundreds  of  thousands  of  people  to-day  are 
wondering  why  something  happens  who  would 
not  have  had  their  imaginations  excited  had 
it  not  been  for  radio.  Each  night  sees  a 
new  connection  tried,  new  types  of  apparatus 
substituted  for  old,  and  subsequent  comparison 
of  notes  with  a  pal  who  has  been  trying  some- 
thing else. 


92 


Radio  Broadcast 


EXPERIMENTING  WITH  RADIO  TELEPHONY  IN  A  NEW  YORK  TROLLEY  CAR 
The  Third  Avenue  Railway  Company,  in  conjunction  with  the  General  Electric  Company,  has  completed  a  series  of  ex- 
periments wherein  radio  carrier  currents  are  used  on  the  feeders  and  trolley  wires  of  its  overhead  system  as  a  means  of  com- 
munication between  points  on  the  system.  The  transmitters  and  receivers  are  similar  in  many  respects  to  the  general  run 
of  broadcasting  outfits  and  satisfactory  communication  has  been  established  between  substations  and  dispatchers'  offices 
and  the  trolleys.  Since  the  receiving  point  may  be  at  any  point  of  the  line,  emergency  calls  will  reach  their  destination  in 
record  time  and  the  exact  nature  of  the  apparatus  needed  to  remedy  whatever  troubles  may  develop  will  be  transmitted.  1  n 
this  way,  operating  delays  will  be  reduced  to  a  minimum.    Conductor  George  Dwyer  is  shown  trying  out  the  new  apparatus 


All  the  good  things  in  radio  haven't  yet  been 
discovered.  To  be  sure,  regeneration  and 
heterodyne  reception  cannot  be  re-discovered 
and  their  rich  rewards  again  be  obtained,  but 
who  knows  what  still  more  interesting  and 
valuable  ideas  are  hidden,  awaiting  some  in- 
vestigator's disclosure?  According  to  the 
theory  of  probability,  perhaps  not  more  than 
one  in  a  hundred  thousand  listeners  will  dis- 
cover something  which  is  commercially  worth 
much,  but  the  fun  and  exhilaration  of  testing 
and  experimenting  is  open  to  all,  and  this  kind 
of  work  is  in  itself  sufficient  reward. 

It  is  not  ordinarily  possible  to  carry  out  tests 
on  our  antennas,  as  the  local  conditions  general- 
ly fix  their  installation,  but  with  the  coming  of 


summer  and  vacations  and  auto  tours,  a 
fascinating  field  of  work  is  opened  for  the  radio 
enthusiast.  How  does  a  signal  decrease  in  in- 
tensity as  the  distance  from  the  transmitting 
station  increases?  Does  it  decrease  as  rapidly 
if  we  stay  near  a  large  river  as  if  we  move  over 
country  away  from  it?  How  far  will  a  crystal 
set  receive?  Does  ground  resistance  really 
have  much  to  do  with  the  strength  of  a  signal? 
Let's  try  it  by  grounding  our  antenna  right  in 
the  stream  by  which  we  are  camped  and  by 
laying  a  counterpoise  wire  on  the  dry  ground,  cr 
by  using  the  automobile  frame  as  ground,  this 
being  well  insulated  from  ground  by  the  tires. 
Is  a  single  wire  antenna  actually  as  directional 
as  "everybody  says?"    It  will  be  easy  to  find 


The  March  of  Radio 


93 


out  by  stringing  the  an- 
tenna to  different  trees  in 
different  directions  with 
respect  to  the  transmitting 
station.  I  s  the  radio  com- 
pass a  reliable  way  of  lo- 
cating a  radio  station,  or 
does  the  presence  of 
streams,  ocean  shore,  etc. 
greatly  affect  its  accuracy? 
Using  loop  antenna,  maps, 
and  a  magnetic  compass, 
the  tourist  may  answer  the 
question  for  himself.  Is 
there  really  a  detrimental 
effect  caused  by  trees 
around  the  receiving  an- 
tenna? It's  perfectly  sim- 
ple to  find  out  by  trying. 

While  the  answer  to 
these  questions,  even  if  reli- 
ably obtained,  will  not  ma- 
terially enrich  the  experi- 
menter, the  "finding  out" 
will  prove  interesting  and 
fascinating  to  the  average 
man  and  the  work  (or  play) 
involved  in  determining 


the  answer 
worth  while, 
increase  the 
profit  derived 
summer's  trips 


will  be  well 
So  let  radio 
pleasure  and 
from  this 
-take  the 


radio  set  along  with  you  so 
that  you  can  experiment 
when  the  urge  is  upon  you, 
and  when  the  set  is  not 
being  used  for  experiment- 
ing it  will  keep  you  in  touch 
with  your  favorite  stations 
and  make  the  evenings  more  pleasurable  to  you 
and  to  the  others  who  will  be  sure  to  visit  the 
tourist  who  has  his  radio  along. 

Hoodwinking  the  Listeners-In 

IT  was  not  long  ago  that  we  called  to  the 
attention  of  those  who  make  up  the  pro- 
grams of  the  broadcasting  stations  their 
responsibility  to  the  radio  public  for  the  materi- 
al sent  out.  Programs  are  generally  made  up 
some  weeks  in  advance  so  that  the  excuse  of  "  no 
time"  cannot  be  offered  in  extenuation.  Man- 
agers must  assume  the  same  responsibility  for 
the  quality  of  the  material  sent  out  from  their 


©  Underwood  &  Underwood 
SIR  BASIL  THOMSON  BROADCASTING  HIS  FAREWELL  TO  AMERICA 
The  former  Director  of  the  Special  Branch  (detective  division)  of  Scotland  Yard 
giving  from  WJZ's  Waldorf  Astoria  studio,  in  New  York,  his  last  talk  before  sailing 

for  the  Bahamas 


station  as  the  average  commercial  house  does 
for  the  goods  purchased  through  it.  If  the  ma- 
terial to  be  broadcasted  lies  outside  the  realm  of 
knowledge  of  the  manager,  he  should  call  to  his 
assistance  some  acknowledged  authority  who 
can  vouch  for  the  reliability  of  the  lecture. 
But  it  would  seem  that  for  talks  on  radio 
matters  the  manager  himself  should  assume 
the  responsibility.  We  wonder  why  an  attempt 
to  hoodwink  the  listening  public  as  to  the 
possibilities  of  the  crystal  receiver  was  recently 
permitted.  "Operating  a  loud  speaker  from 
a  crystal  set  "— any  manager  who  thinks  that 
possible  should  give  up  his  job  and  take  one 
speculating  in  oil  or  some  other  field  where  his 


94 


Radio  Broadcast 


TRANSMITTING  RADIO  MESSAGES  WITH  THE  TELETYPE  MACHINE 
Chief  Gunner  J.J.  Delaney,  at  the  naval  radio  station,  Washington,  has  only  to  press  the  keys  as  if  using  an  ordinary  type- 
writer: the  letters,  automatically  "  put  on  the  air"  as  radio  code  symbols,  are  instantaneously  decoded  again  at  the  receiv- 
ing station  by  a  machine  which  also  prints  them,  "in  English,"  exactly  as  they  are  sent 


imagination  will  have  sufficient  play.  A 
crystal  set  alone  could  not  possibly  operate  a 
loud  speaker,  unless  the  listener  was  perhaps 
within  a  stone's  throw  of  the  transmitting 
station  and  even  then  the  signal  would  be  very 
poor.  How  then  did  this  promotor  propose  to 
operate  a  loud  speaker  from  a  crystal  set?  By 
acceding  to  his  request  to  write  for  particulars 
we  found  that  it  was  necessary  to  have  an 
ordinary  audio-frequency  amplifier,  of  the 
vacuum-tube  type,  to  help  the  crystal! 

Why  the  speaker  was  allowed  to  speak  on  this 
misleading  topic  we  should  like  to  know.  Had 
he  said  that  his  method  involved  the  use  of 
ordinary  triode  amplifiers  he  would  never 
have  received  the  number  of  letters  he  did. 
The  pile  of  letters,  "  more  than  received  by  any 
previous  speaker  at  the  station,"  as  was  an- 
nounced, represented  just  so  many  radio 
listeners  who,  trusting  to  the  judgment  of  the 
station  manager,  had  been  hoodwinked  and 
have  lost  much  of  their  faith  in  the  accuracy 
of  the  material  sent  out  from  this  station.  A 
little  of  such  misleading  advertising  goes  a  long 


way  towards  spoiling  the  reputation  of  the  man 
who  so  questionably  advertises  his  goods  by 
radio.  Instead  of  bringing  sales,  such  broad- 
cast talks  will  eventually  ruin  completely 
the  advertiser's  estimate  of  the  value  of  radio. 
Discreet  advertising,  which  merely  announces 
that  the  A.  B.  Company  of  C  and  D  streets  is 
offering  the  program  for  the  next  hour  and 
would  be  pleased  to  receive  suggestions  from 
the  radio  audience  as  to  future  programs,  will 
probably  pay  in  the  long  run  even  though  its 
immediate  value  may  not  be  apparent;  but 
advertising  which  insults  the  intelligence  of  the 
listener,  as  that  on  crystal  sets  and  loud 
speakers,  leaves  a  bad  impression — involving 
not  only  the  speaker  but  also  the  station. 

A  Big  Demand  for  Educational  Radio  ? 

WILL  radio  serve  as  an  adjunct  to 
ordinary  methods  of  college  in- 
struction? Will  the  instruction 
given  in  the  class  room  be  supplemented  to  an 
appreciable  degree  by  broadcasted  lectures? 


The  March  of  Radio 


95 


There  has  been  much  talk 
lately  by  the  National 
Radio  Chamber  of  Com- 
merce about  helping  the 
colleges  to  establish  a  radio 
broadcasting  service;  be- 
sides the  question  as  to 
just  what  the  Chamber  can 
do  to  help  in  the  work,  the 
very  important  question 
must  first  be  answered :  I  s 
there  a  real  demand  from 
the  radio  public  for  educa- 
tional lectures  of  the  kind 
given  in  college,  class 
rooms? 

There  is  undoubtedly  a 
demand  for  educational 
material  in  radio  broad- 
casting, but  the  demand  is 
for  the  indirectly  educa- 
tional subjects — the  kind 
of  material  one  gets  in 
listening  to  good  musical 
numbers,  or  opera.  One 
cannot  help  receiving 
education  and  inspiration 
from  good  music  well  rend- 
ered and  there  is  an  in- 
creasing demand  for  it. 
The  managers  of  the  broad- 
casting stations  agree  that 
a  great  percentage  of  their 
audiences  prefer  operatic 
selections  to  jazz.  On  the 
other  hand  these  same 
managers  are  unanimous 
in  their  opinion  that  lectures  of  the  kind  and 
quality  given  in  class  room  will  not  hold  the 
radio  audience. 

In  the  class  room,  the  gesture  and  personality 
of  the  instructor,  and  blackboard  illustration, 
as  well  as  the  student's  interest  in  the  subject 
matter,  serve  to  hold  his  attention.  But  no 
such  advantages  rest  with  the  radio  lecturer; 
his  first  phrase  must  capture  the  interest  and 
curiosity  of  the  listener  and  every  sentence  must 
be  so  meaty  and  to  the  point,  with  prediction  of 
more  interesting  things  to  come,  that  there  is  no 
inclination  to  re-tune  to  a  competing  musical 
program.  Neither  politeness  nor  a  desire  to 
"stand  in  "with  the  instructor  can  command  the 
interest  of  the  radio  listener — the  subject  mat- 
ter alone  must  be  presented  in  such  an  attrac- 
tive fashion  that  it  is  considered  worth  while. 


A  SERMON  S  A  SERMON   FOR  ALL  THAT 


A  glance  at  the  quality  of  the  pictures  offered 
to  the  movie  public  indicates  that  if  a  demand 
for  educational  films  has  been  made,  the  pro- 
ducers have  estimated  it  to  be  of  almost  negligi- 
ble importance.  Occasionally  a  film  with  a 
certain  amount  of  educational  material  in- 
corporated does  appear,  but  the  meagre  success 
of  such  attempts  to  educate  the  masses  is 
evidenced  by  the  scarcity  of  pictures  of  this 
kind.  If  there  were  two  movie  houses  of 
equal  accessibility  and  price,  one  showing  some 
important  industrial  process  or  historical  devel- 
opment and  the  other  putting  on  the  latest 
and  hottest  from  Hollywood,  there  is  no  doubt 
whatever  which  house  would  echo  with  empti- 
ness and  which  would  need  stampede  regulation 
at  its  portals. 

Now  it  may  well  be  questioned  whether  the 


g6 


Radio  Broadcast 


NO  HANDLE  TO  TURN  ON  THIS  HURDY-GURDY 


This  outfit  recently  made  its  appearance  on  the  streets  of  London,  where  aU  and  sundry  were  regaled  with  radio  melodies. 
Within  the  box  is  a  4-tube  receiver,  and  two  loud  speakers  facing  in  opposite  directions.    It  is  said  that  everyone  from 
a  newsboy  to  an  M.  P.  can  be  stopped  in  his  tracks  at  200  yards'  range  when  this  apparatus  opens  up 


analogy  of  the  movies  is  justifiable,  on  the 
ground  that  the  average  movie  audience  is,  in 
general,  less  particular  about  the  quality  of  its 
entertainment  than  the  radio  audience,  that 
the  educational  material  which  would  fall 
flat  when  offered  to  one  class  would  be  eagerly 
awaited  by  the  other.  This  is  an  hypothesis 
which  cannot  be  answered  at  this  time;  but  we 
rather  question  its  accuracy.  The  only  method 
of  getting  accurate  information  on  such  topics 
is  by  analyzing  the  correspondence  received  by 
the  managers  of  the  broadcasting  stations,  and  it 
is  evidently  impossible  to  use  this  source  of  in- 
formation until  the  experiment  has  been 
thoroughly  tried  out.  It  may  well  be  that  we 
shall  find  a  sufficiently  wide-spread  interest  in 
some  branches  of  education  to  make  it  worth 
while,  although  for  other  branches  there  is  no 
appreciable  demand. 

In  this  connection  we  note  with  interest  that 
morning  broadcasting  between  1 1  :oo  A.  M. 
and  noon  has  met  with  unexpected  success. 


Feeling  that  many  women  would  appreciate 
lectures  of  an  informative  nature,  The  Town 
Hall,  a  New  York  organization  devoted  to 
promoting  worth  while  things,  especially  in 
music  and  literature,  has  started  to  send  out 
through  WEAF  their  morning  lectures.  From 
the  letters  received  those  responsible  for  the 
experiment  feel  well  pleased.  One  appreciative 
listener  writes:  "I  feel  that  it  is  a  wonderful 
privilege  for  a  busy  house  mother  to  pause  for 
an  hour  and  be  completely  'transported'  to 
other  lands  and  scenes.  When  our  tired 
families  are  home  at  night  the  radio  is  theirs 
for  refreshment,  but  the  morning  is  mother's 
own,  and  I  for  one  sincerely  hope  that  the 
lectures  will  be  continued." 

So  do  we.  Here  is  apparently  a  real  service 
for  radio  to  perform,  and  we  hope  sufficienc 
stations  will  take  up  the  idea.  It  cannot  be 
expected  that  the  mothers  will  be  able  to  get 
reception  over  thousands  of  miles  as  their 
young  sons  sometimes  do  in  the  night  time  when 


The  March  of  Radio 


97 


conditions  are  favorable;  it  will  be  necessary 
for  many  stations  well  distributed,  to  under- 
take this  service  before  it  can  be  widely  ap- 
preciated. 

But  this,  however,  is  quite  possible.  The 
large  department  stores,  which  most  need  to 
convince  the  mother  of  their  value  and  desire  to 
serve,  are  just  the  places  where  the  broadcast 
stations  are  quite  generally  installed.  What 
better  way  of  advertising  to  a  picked  clientele? 
We  suggest  that  the  experiment  started  by  the 
Town  Hall  management  be  taken 
up  all  over  the  country;  the  in- 
crease in  cost  due  to  running  the 
station  an  hour  in  the  morning  is 
not  great  and  the  return  might 
possibly  be  greater  than  it  is  from 
the  more  expensive  evening  pro- 
gram. It  seems  that  not  only 
general  lectures  on  art  and  litera- 
ture are  suitable  for  such  a  morn- 
ing program,  but  the  courses  in 
home  economics  and  similar  sub- 
jects which  are  offered  in  the  better  colleges 
should  prove  attractive  to  the  home  keepers 
of  the  country. 

The  Accurate  Measurement  of  Signals 

C~T  month  we  referred  to  the  theory  that 
radio  waves  do  not  travel  in  all  directions 
with  equal  ease.  After  comparing  statis- 
tics gathered  from  listeners  located  in  various 
directions  around  a  transmitting  station,  we 
have  been  forced  to  the  conclusion  that  such 
is  actually  the  case.  Since  we  commented  on 
this  matter  there  has  appeared  a  paper  on  the 
accurate  measurements  of  radio  signals,  a 
paper  prepared  by  three  of  the  research  engine- 
ers of  the  Western  Electric  Company.  This 
company  has  had  opportunities  to  sell  hundreds 
of  transmitting  stations,  but  has  consistently 
"lost"  these  sales  when  it  has  seemed  that 
the  intended  installation  was  not  a  wise  one, 
either  from  the  standpoint  of  the  purchaser 
or  the  radio  public.  In  following  out  this 
policy  the  engineers  have  seen  that  it  would 
be  very  necessary  for  them  to  know  not  only 
the  general  conditions  under  which  the  station 
was  to  be  used,  the  wavelength,  probable  inter- 
ference, etc.,  but  the  effect  of  the  location  of 
the  station.  This  point  had  been  brought  home 
to  them  very  forcibly  by  the  comparatively 
poor  performance  of  their  own  station,  WBAY. 
Before  the  preliminary  tests  on  this  station 


were  carried  out  it  seemed  that  the  performance 
must  be  excellent,  but  actually  it  was  disap- 
pointing. At  the  desired  wavelength,  400 
meters,  the  antenna  system  radiated  poorly; 
at  a  very  much  longer  wavelength,  about  800 
meters,  it  performed  very  well,  the  signals 
in  the  field  were  much  louder  than  could  possi- 
bly have  been  predicted. 

The  peculiar  behavior  of  this  antenna  at 
once  convinced  the  research  men  and  designers 
that  they  must  have  accurate  data,  not  guesses, 
on  the  power  radiated  from  the 
antenna.  How  much  better  was 
the  signal  at  800  meters  than  at 
400  meters?  How  did  it  vary  in 
strength  as  the  wavelength  was 
varied  between  these  limits?  After 
a  year  or  more  of  work,  a  measur- 
ing machine  had  been  designed, 
built,  and  tested,  which  proved 
satisfactory.  It  was  mounted  on 
a  truck  and  taken  out  into  the  field 
for  making  signal  measurements  on 
the  defective  station.  These  tests  showed  con- 
clusively that  the  radiated  power  at  800  meters 
was  about  100  times  as  great  as  at  400  meters, 
whereas  ordinary  theory  predicts  it  should  be 
only  one  quarter  as  much.  Theory  and  practice 
differed  by  a  factor  of  400.  It  was  found  that 
the  station,  located  on  the  top  of  a  sky-scraper, 
was  using  as  its  antenna,  not  the  wire  system 
which  had  been  strung  on  the  steel  poles  erected 
on  the  roof  of  the  building,  but  the  whole 
building. 

Having  used  the  measuring  apparatus  for  the 
solution  of  this  special  problem  it  was  next  put 
to  the  task  of  measuring  signal  strengths  at 
various  points  around  transmitting  stations. 
The  apparatus,  being  self-contained  and  mount- 
ed in  a  small  truck,  could  be  quickly  carried  to 
any  point  at  which  it  was  desired  to  measure  the 
signal  strength.  So  far,  it  has  worked  only  in 
the  neighborhood  of  New  York,  but  even  in  this 
limited  territory  it  has  achieved  remarkable 
results.  By  making  measurements  at  various 
points,  in  all  available  directions,  the  points 
all  being  approximately  twenty-five  miles 
from  the  New  York  station  doing  the  trans- 
mitting, it  was  found  that  northeast  of  the 
station  the  electric  field  of  the  signal  was  only 
one  tenth  as  strong  as  it  was  in  a  northwest 
direction.  This  means  that  the  signal  received 
northeast  of  the  station  would  be  only  one 
hundredth  as  strong  at  an  equally  distant 
point  in  a  westerly  direction,  thus  confirming 


98 


Radio  Broadcast 


WINNER  OF  THE  HOOVER  CUP  FOR  THE  BEST  AMATEUR  STATION 
The  Hoover  cup,  awarded  annually  to  the  owner  of  America's  best  amateur  radio  station,  has  been  presented  to  Frederick 
R.  Ostman  of  Ridgewood,  N.  J.,  operator  of  station  20M.  This  trophy  is  the  highest  honor  in  amateur  radio  and  is  awarded 
by  the  Department  of  Commerce  through  Secretary  Hoover  to  the  best  all  around  amateur  station,  the  major  part  of  which 
is  home-made.  Mr.  Frank  Frimmerman's  station,  2FZ,  located  in  the  Bronx,  New  York,  was  judged  the  second  best 
amateur  station.    2FZ  was  described  and  illustrated  in  Radio  Broadcast  for  April 


the  decision  reached  by  statistically  comparing 
notes  of  various  receiving  stations  at  different 
points. 

Not  only  in  showing  conclusively  the  trouble 
in  existing  stations  but  in  making  it  possible  to 
find  a  good  location  for  a  new  station,  this 
apparatus  has  already  justified  the  time  and 
expense  required  to  develop  it.  By  putting  up 
a  temporary  antenna  on  the  building  where  it 
was  anticipated  the  new  station  was  to  be 
erected  and  making  signal  measurements  in 
the  surrounding  territory  it  was  shown  that 
very  poor  results  would  be  obtained.  Not 
only  did  the  results  show  that  the  building  was 
too  high  to  be  suitable  for  a  400-meter  station 
but  the  location  of  the  building  among  neigh- 
boring sky-scrapers  was  such  that  in  the  direc- 
tion where  most  of  the  prospective  listeners 
were  located  the  transmission  was  particularly 


poor.  Other  temporary  antennas  were  erected 
on  other  buildings  available  for  the  station,  and 
the  field  measurements  showed  decisively  the 
superiority  of  one  of  the  buildings  over  the 
others. 

The  value  of  these  measurements  will  be 
apparent  when  it  is  mentioned  that  one  of 
these  stations  costs  about  $25,000  to  install; 
as  these  preliminary  field  measurements  have 
shown  the  chosen  site  to  be  about  five  times  as 
good  as  the  one  which  would  have  been  chosen 
had  the  measurements  not  been  made,  it  is 
evident  that  they  increased  the  effectiveness 
of  that  $25,000  investment  in  the  ratio  of  five  to 
one.  The  work  of  the  three  engineers  respon- 
sible for  the  development  of  this  measuring 
apparatus — Bown,  Englund,  and  Friis — has 
been  well  done,  and  they  deserve  the  hearty 
thanks  and  congratulations  of  all  listeners-in. 


The  March  of  Radio 


99 


Help  the  Boy  Scout  with  His  Radio 

THERE  is  probably  no  doubt  in  any  one's 
mind  regarding  the  value  of  the  Boy 
Scout  movement.  If  there  is,  let  the 
doubter  meet  one  of  the  troops  on  the  hike 
and  get  in  conversation  with  the  members  or 
listen  to  what  their  Scoutmaster  has  to  say. 
These  healthy,  wide-awake  boys  will  soon  be 
the  leaders  and  backbone  of  the  country.  The 
development  in  them  of  the  right  way  of 
living  and  thinking  is  the  most  worth-while 
work  in  which  any  one  could  engage.  These 
boys'  love  of  the  outdoors  will  undoubtedly 
make  them  more  suitable  for  framing  and 
maintaining  laws  regulating  our  natural  re- 
sources, a  problem  which  will  have  assumed 
tremendous  importance  by  the  timethey  grow 
up.  The  spirit  of  fair  play,  with  which  every 
Scoutmaster  seeks  to  imbue  his  followers,  and 
which  Scouts  so  generally  show,  is  an  attribute 


which  will  go  a  long  way  toward  solving  the 
difficult  economical  problems  of  continually 
growing  importance.  From  whatever  angle 
it  is  viewed,  the  Scout  movement  shows  up  so 
well  that  no  intelligent  man  could  reasonably 
withhold  his  support. 

A  Scout  activity  which  will  serve  the  double 
purpose  of  assisting  the  Scoutmaster  in  laying 
out  interesting  tasks  for  his  followers  and  of  di- 
recting the  boys  into  accurate  and  interesting 
experimental  work  has  to  do  with  radio.  Every 
troop  on  the  hike  this  summer  should  have 
along  with  it  a  radio  outfit  for  listening  to  the 
distant  transmitting  stations.  Receiving  sets 
using  dry-cell  tubes  are  not  difficult  to  transport, 
and  in  the  hands  of  a  skillful  operator  will  re- 
ceive hundreds  of  miles. 

To  see  how  quickly  an  antenna  could  be 
strung  to  a  neighboring  tree  and  the  set  be  put 
into  operating  condition  should  prove  an  in- 
teresting addition  to  the  Scouts'  varied  activi- 


AN  APARTMENT  HOUSE  STATION  THAT  SUPPLIES  BROADCASTS  TO  72  TENANTS 
The  landlord  of  a  Newark,  N.  J.,  apartment  house  has  installed  a  receiver  in  his  building,  which  gets  broadcast  programs 
from  all  over  the  East  and  Middle  West.    Each  family  or  tenant  is  a  subscriber,  having  only  to  plug  in  phones  or  a  loud- 
speaker on  the  line  terminating  in  his  own  living-room,  to  receive  the  concerts  that  Operator  James  Walsh  tunes  in 


100 


Radio  Broadcast 


ties.  In  case  two  or  more  sets  are  available, 
contests  to  see  who  can  first  get  "in  touch" 
with  the  outside  world  would  be  welcomed  by 
the  troop.  Our  purpose  in  writing  this  is  not 
so  much  to  interest  the  Scouts  in  radio — they 
are  interested  in  it  already —  but  to  let  their 
dads  know  that  a  request  for  financial  assistance 
toward  a  radio  outfit  may  offer  them  a  mighty 
good  investment. 

Commercial  Broadcasting  in  Germany 

IN  SPITE  of  the  troubled  condition  still  ex- 
isting in  Germany,  radio  is  apparently 
slowly  progressing  along  the  paths  it  has 
already  followed  in  this  country.  Ger- 
many has,  in  the  past,  been  in  the 
forefront  of  radio  development;  her 
engineers  andartisans  have  turned  out 
some  wonderful  radioequipment.  The 
Goldschmidt  alternator  is  a  marvel 
from  the  standpoints  of  both  design 
and  construction,  and  the  Telefunken 
marine  sets  were  probably  as  efficient 
as  any  ever  put  into  ship  service. 

Had  the  war  not  occurred,  broadcasting  by 
radio  telephone  would  probably  have  pro- 
gressed technically  in  Germany  as  far  as  it  has 
here,  and  certainly  it  would  have  been  better 
controlled  and  regulated  by  the  Government.  It 
is  difficult  to  imagine  how  government  action, 
anywhere,  could  have  resulted  in  a  condition 
worse  than  that  at  present  existing  here.  A 
private  company  (Eildienst  Gesellschaft)  has 
started  the  commercial  exploitation  of  radio 
broadcasting  by  renting  receiving  equipment 
to  subscribers,  who  pay  500,000  marks  annual- 
ly for  the  service  and  use  of  the  sets.  The 
present  subscribers  are  mostly  banks  and  busi- 
ness houses,  and  the  news  broadcasted  twice 
daily  contains  principally  financial  notes  from 
foreign  lands.  An  agency  in  New  York  trans- 
mits stock  quotations,  and  other  commercial 
matters  to  the  high-power  station  at  Nauen, 
near  Berlin.  The  material  is  then  broadcasted 
over  Germany  from  a  government  station 
which  this  private  company  leases  for  the  re- 
quired time.  It  is  anticipated  that  the  material 
despatched  by  the  American  agents  will  be  re- 
ceived by  the  broadcast  licensees  within  ten 
minutes  of  the  time  it  is  sent  from  New  York. 

We  wonder  just  what  the  company  antici- 
pates doing  to  the  firms  who  'make  their  own' 
and  so  are  able  to  receive  the  broadcast  service 
without  paying  the  subscriber's  fee. 


A  New  Station  for  Sweden 

AN  ANNOUNCEMENT  from  the  De- 
/\  partment  of  Commerce  gives  the  par- 
I  V  ticulars  about  the  new  station  to  be 
erected  by  the  Swedish  Government  at  Gote- 
burg,  the  port  at  which  cables  enter  Sweden. 
The  contract,  which  was  obtained  by  an  Ameri- 
can company  in  competition  with  British, 
French,  and  German  bidders,  will  furnish  for 
the  station  a  200- KW  Alexanderson  alternator. 
The  steel  antenna  towers  will  be  similar  to 
those  of  the  radio  Corporation  station  at  Rocky 
Point,  with  which  station  the  Swedish  station 
is  expected  to  communicate  directly.  Most  of 
the  apparatus  will  be  built  in  America, 
but  the  towers  will  be  designed  and 
built  in  Sweden. 

It  is  expected  that  the  station  will 
be  completed  before  the  end  of  the 
year,  and  that  a  large  transoceanic 
traffic  will  be  built  up  with  this  new 
connection.    At  present,  Sweden  has 
■j!^       to  rely  on  other  countries  for  making 
its  foreign  connections  and  too  fre- 
quently this  has  proved  commercially  disad- 
vantageous. 

One  special  service  which  it  is  anticipated  will 
be  inaugurated  through  this  new  station  is  free 
medical  advice  to  ships  at  sea,  the  advice  to 
come  from  the  best  hospital  staffs  in  Sweden. 
As  Sweden  is  essentially  a  maritime  nation 
with  thousands  of  seamen  on  the  fishing  banks 
within  radio  reach  of  their  home  ports, this 
service  will  probably  prove  of  such  worth  as  to 
strengthen  further  the  Government's  deter- 
mination to  maintain  her  communication 
system  well  abreast  of  modern  developments, 
a  work  in  which  the  Government  has  been 
actively  engaged  during  the  last  three  years. 

Increased  Speed  of  Radio  Traffic 

SEVERAL  times  there  has  been  announced 
through  the  press  the  accomplishment  of 
high-speed  radio  communication,  but 
in  general  these  spectacular  results  have  been 
maintained  for  a  short  time  only,  when  the 
conditions  were  especially  favorable.  A  recent 
communication  from  the  Radio  Corporation 
shows  that  the  development  of  the  automatic 
transmitter  and  high-speed  receiver  required  for 
communication  at  rates  in  excess  of  thirty  words 
a  minute  is  steadily  progressing. 

The  report  states:  "On  the  last  voyage  of  the 


The  March  of  Radio 


IOI 


U.  S.  FOREST  SERVICE  BOATS  IN  ALASKAN  WATERS 
The  Wanigan,  floating  home  of  the  men  who  patrol  the  Tongass  National  Forest,  keeps  in  communication  by  radio 
with  its  motor  boats.    The  latter  serve  as  tenders,  towing  the  houseboat  from  place  to  place  along  the  shore 
line,  bringing  supplies  and  performing  various  duties  necessary  to  the  protection  of  the  territory.    The  Tamm, 
shown  at  the  left,  is  the  headquarters  boat,  which  has  survived  many  storms  and  by  the  use  of  radio  has  helped  to  save 

both  life  and  property 


White  Star  liner  Majestic,  the  world's  greatest 
steamship,  radio  messages  were  exchanged  with 
shore  stations  of  the  Radio  Corporation  of 
America  at  speeds  of  more  than  eighty  v/ords  a 
minute  when  the  vessel  was  one  thousand 
miles  at  sea.  Ordinarily,  speeds  in  excess  of 
about  twenty-five  words  a  minute  cannot  be 
attained  by  hand  sending,  and  in  order  to  meet 
the  demands  of  increasing  radiogram  traffic 
created  by  the  large  passenger  liners,  machine 
sending  must  be  used,  in  which  case  a  given 
message  can  be  sent  and  received  in  one  third 
the  time  required  by  manual  methods. 

"The  earlier  experiments  aboard  the  Majestic 
permitted  only  one-way  high-speed  trans- 
mission, namely  from  ship  to  shore,  there  being 


no  apparatus  on  board  the  vessel  capable  of 
receiving  high-speed  transmission.  In  order 
to  effect  two-way  high-speed  telegraphic 
service  on  the  vessel  during  the  last  voyage  to 
New  York  it  was  equipped  by  the  Marconi 
Company  with  a  high-speed  receiver  which 
worked  most  satisfactorily.  High-speed  signals 
were  also  received  from  Paris  at  a  distance  of 
eight  hundred  miles  at  eighty  words  per  minute. 
Wireless  press  was  completely  and  perfectly 
recorded  by  the  automatic  receiver  through 
medium  static.  The  principal  benefits  will  be 
derived  from  the  new  apparatus  when  it  is  in- 
stalled on  all  vessels  of  the  larger  type  which 
handle  great  volumes  of  traffic." 

J.  H.  M. 


Radio  in  Summer  Camps 


By  ELON  JESSUP 

Whether  you  are  a  father,  mother,  or  young  son  or  daughter,  you  will  enjoy  this  interesting  article  about 
the  increasing  use  of  radio  in  boys'  and  girls'  camps. 

Possibly  you  have  heard  of  Lloyd  Espenshied,  the  radio  engineer  who  was  instrumental  in  bringing  about 
the  first  communication  by  radio  telephony  between  Washington  and  Paris,  and  Washington  and  Honolulu; 
or  you  may  have  operated  one  of  the  receivers  designed  by  H.  R.  Langley  oftthe  General  Electric  Company; 
but  it  is  unlikely  that  you  know  that  both  these  men  first  became  interested  in  radio  at  a  certain  summer 
camp  up  on  Lake  Champlain. 

If  camp  life  holds  any  appeal  for  you,  you  should  not  fail  to  read  Mr.  Jessup's  description  of  what  radio 
is  doing  for  young  Americans  out-of-doors. — The  Editor. 


summer,  more  than  500,000  Ameri- 
can boys  and  girls,  ranging  in  age 


¥AST 

from  six  to  eighteen,  were  members  of 
j  summer  camps.    Considering  that  a 
few  years  age >.  within  the  memory  of 
all  of  us,  the  institution  of  summer  camps  for 


young  people  was  almost  unknown,  this  is  a 
pretty  fair  indication  of  how  firmly  the  idea 
has  taken  hold. 

The  exceptional  educational  and  recreational 
opportunities  for  young  America  which  these 
camps  represent  is  too  well  known  to  require 


IN  THE      SHACK      AT  CAMP  DUDLEY 
This  camp  has  been  using  radio  since  1908!    Every  summer,  a  club,  consisting  of  enthusiastic  experimenters,  operators, 
and  others  interested  in  radio,  holds  weekly  meetings  and  engages  in  all  such  activities  as  regular  transmission  and  recep- 
tion, construction  of  apparatus,  and  code  and  theory  classes 


Radio  in  Summer  Camps 


103 


CALIFORNIA  SCOUTS  WITH  THEIR  3-TUBE  RECEIVER  AND  SPARK-COIL  TRANSMITTER 

Bulky  apparatus  can  be  carried  to  the  camping  place  by  auto  or  trek  cart,  but  an  evident  improvement  for  a  portable 
station  would  be  the  use  of  dry-cell  tubes,  making  the  heavy  storage  battery  unnecessary.    These  Scouts  use  a  strip  of  wire 
mesh,  which  they  place  in  the  water  or  bury  in  damp  earth,  for  their  ground  connection 


much  comment.  As  one  camp  director  has 
expressed  it,  you  find  in  the  well-run  camp 
"healthful  recreation,  wholesome  companion- 
ship and  educational  advantages  combined  in 
a  program  of  activities  that  is  in  keeping  with 
the  progressive  tendencies  of  the  day." 

To  the  person  interested  keenly  in  radio, 
the  phrase  "progressive  tendencies  of  the  day" 
may  perhaps  give  rise  to  curiosity  as  to  just 
what  is  being  done  with  radio  in  these  numer- 
ous camps.  For  here,  unquestionably,  is  an 
activity  having  at  once  recreational  and  educa- 
tional value.  Logically,  it  would  seem  to 
have  a  very  real  place  in  the  average  camp 
program. 

The  answer  in  a  general  way  is  as  follows: 
in  Boy  Scout  camps,  the  use  of  radio  and  the 
interest  in  it  are  practically  universal,  and 
have  been  for  some  time;  a  Boy  Scout  troop 
not  having  a  radio  outfit  is  a  rare  exception. 
Furthermore,  this  may  be  applicable  even  to 
winter  camps,  as  indicated  by  six  hundred  Boy 
Scouts  who  last  winter  spent  their  holidays 
camping  in  the  Interstate  Park  of  New  York 
and  New  Jersey.  Radio  sets  were  almost  as 
thick  as  snowshoes  and  skis. 

As  for  the  camps  which  are  not  connected 


with  the  Boy  Scout  movement — "  private 
camps"  as  they  are  commonly  called — it  may 
be  stated,  broadly,  that  two  summers  ago  there 
was  no  interest  in  radio  to  speak  of,  last  sum- 
mer there  was  a  smattering  of  interest  and 
during  the  coming  season  there  promises  to  be 
a  great  deal,  of  interest. 

Last  summer  1  visited  several  of  these  camps, 
some  of  which  were  for  boys,  others  for  girls, 
and  more  recently  I  have  talked  with  numer- 
ous camp  directors  whose  camps  I  had  not  seen. 
I  wanted  to  know  whether  radio  was  included 
in  their  programs  of  camp  activities,  and  if 
not  I  was  curious  to  learn  the  reasons  for  its 
absence.  Various  attitudes  which  1  met  were 
about  as  follows: 

Some  directors  showed  an  entire  lack  of 
knowledge  and  interest  in  radio  and  expressed 
distaste  at  the  suggestion  of  its  being  used  in 
their  camps.  Other  directors  expressed  in- 
terest in  radio  and  wanted  to  know  more  about 
it.  A  few  directors  freely  acknowledged  that 
radio  had  proved  a  valuable  addition  to  their 
camp  activities. 

As  regards  the  first  of  these  three  attitudes: 
there  are  some  camp  directors  who  frankly  ob- 
ject to  having  a  radio  set  on  their  premises. 


io4 


Radio  Broadcast 


THE  SET  IN  OPERATION 

A  good  aerial  can  be  strung  up  almost  anywhere,  in  the  country,  and  even  a  very  small  portable  transmitter  will  send 
out  its  signals  with'a  practical  range  of  a  mile  or  so.    The  single-tube  transmitter  is  undoubtedly  what  Scouts  and  campers 
are  going  to  use  more  and  more.    With  careful  planning,  all  apparatus  for  both  transmitting  and  receiving,  except  the 
batteries,  might  be  placed  within  a  box  the  size  of  either  of  the  receiving  cabinets  shown  in  the  picture 


Their  reason  for  feeling  this  way  about  it  is 
that  they  wish  completely  to  divorce  camp  life 
from  any  suggestion  of  city  life.  A  radio  set 
they  classify  more  or  less  with  automobiles  and 
the  movies;  something  of  a  distracting  in- 
fluence. During  the  two  or  three  months 
wnile  the  boys  or  girls  are  in  camp,  these  direc- 
tors feel  that  they  should  be  living  in  as  com- 
pete isolation  as  possible  from  the  outside 
world. 

I  report  this  attitude,  without  comment,  as  1 
found  it.  Those  who  hold  it,  are,  1  believe  in 
the  minority. 

The  majority  of  camp  directors  are  in  the 
second  classification  which  1  have  given;  theirs 
is  the  "  we'd  like  to  know  about  it "  stage.  And 
this  stage  in  turn  is  perhaps  evenly  divided 
between  those  who  have  not  had  any  radio  sets 
in  their  camps  so  far  but  contemplate  putting 
them  in,  and,  on  the  other  hand,  those  who 
have  experimented  slightly  with  radio  and 
would  like  to  go  further  with  it. 

Many  camps  have  "  played  "  with  the  idea  of 
radio  but  with  the  exception  of  the  Boy  Scout 
camps,  there  are  very  few  so  far  that  have  gone 
at  the  subject  in  a  really  business-like  way.  As 
I  have  indicated,  however,  there  is  a  growing 


interest  in  radio  both  from  the  standpoint 
of  education  and  entertainment. 

As  regards  girls'  camps,  radio  is  regarded 
almost  exclusively  as  a  means  of  entertainment, 
for  girls  are  not  generally  considered  to  have 
a  mechanical  turn  of  mind;  yet,  as  indicative  of 
the  fact  that  this  commonly  accepted  theory 
does  not  always  hold  true,  1  might  mention 
that  some  time  ago  the  Young  Women's  Chris- 
tian Association  gave  a  course  in  radio  con- 
struction. During  the  coming  season,  the 
Y.  W.  C.  A.  intends  to  install  several  radio 
sets  in  its  summer  camps. 

Boys,  of  course,  are  more  technically  minded 
than  are  girls.  And  almost  all  boys  like  to  hear 
the  baseball  scores  and  listen  to  an  occasional 
concert.  The  wise  camp  director  realizes  full 
well  that  when  a  boy  is  genuinely  interested  in  a 
given  subject,  he  should  by  all  means  be  given 
every  facility  for  expressing  this  interest. 

That  is  one  reason  why  directors,  of  boys' 
camps  especially,  are  turning  more  and  more  to 
radio.  The  boys  themselves  have  to  some  ex- 
tent created  the  demand.  A  boy  brings  to 
camp  a  set  that  he  has  made  at  home  and  a 
goodly  proportion  of  the  rest  of  the  crowd  im- 
mediately wants  to  make  a  set  like  it.  Con- 


Radio  in  Summer  Camps 


105 


sequently,  in  a  number  of  camps,  the  construc- 
tion of  radio  sets  has  become  a  recognized  camp 
activity. 

For  example,  I  have  in  mind  one  camp  in 
which  boys  last  summer  spent  one  hour  each 
day  on  the  construction  of  crystal  sets,  each 
of  which,  after  the  camp  was  over,  was  carried 
proudly  home.  Only  a  comparatively  small 
proportion  of  the  boys  were  engaged  in  this 
activity. 

Yet,  as  I  have  indicated,  camp  directors  as  a 
whole  are  in  something  of  a  quandary  about 
radio  both  as  regards  entertainment  and  in- 
struction. It  is  a  new  subject  to  them  and  they 
are  not  yet  "sold"  on  radio.  No  doubt  there 
are  several  exceptions  to  this  rule  and  I  will  tell 
you  about  the  one  notable  exception  with  which 
i  am  familiar.  1  am  now  speaking  of  a  boys' 
camp  which  is  in  no  way  related  to  the  Boy 
Scout  movement — Camp  Dudley  on  Lake 
Champlain,  a  camp  of  about  two  hundred  boys 
ranging  in  age  from  twelve  to  sixteen. 

Two  significant  facts  are  attached  to  this 
camp,  one  of  these  being  that  it  is  the  oldest 
organized  boys'  camp  in  America  and  the 
other  is  that  wireless  work  has  been  one  of  its 
activities  for  more  than  fifteen  years.  Thus, 


one  has  here  an  exceptional  opportunity  to 
view  methods  and  results. 

First,  as  regards  tangible  results.  The  boys 
who  in  the  past  spent  their  summers  at  Camp 
Dudley  have  grown  up  and  gone  out  into  the 
world.  Some  of  these  boys  when  in  camp  had 
no  idea  about  the  sort  of  work  they  intended 
to  go  into;  others  did.  Take  for  example, 
R.  H.  Langley,  now  in  charge  of  the  receiving 
section  of  the  radio  engineering  department  of 
the  General  Electric  Company.  His  first  in- 
terest in  wireless  was  aroused  when  he  was  a 
boy  in  Dudley.  The  same  is  true  of  Lloyd 
Espenschied,  the  engineer  who  was  instru- 
mental in  bringing  about  the  first  wireless 
communication  between  the  Pacific  Coast  and 
the  Philippine  Islands. 

Radio,  in  its  present-day  phase,  so  far  as 
Camp  Dudley  is  concerned,  dates  back  three 
years.  Then  it  was  that  a  club  was  formed 
among  the  boys,  who  forthwith  became  gleeful 
over  obtaining  permission  from  their  "  Chief," 
H.  C.  Beckman,  to  build  a  "shack"  in  which  to 
house  the  instruments  and  serve  as  a  club- 
house. Carpentry  is  one  of  the  camp  activities, 
so  they  knew  how  to  build  a  real  house  and  they 
made  a  good  job  of  it. 


LOCAL  RECEPTION  ON  A  LARGE   LOOP  ANTENNA 
First  Class  Scout  Malmros  of  Troop  1,  Roslyn,  Long  Island,  tuning  in  signals  from  his  headquarters  radio  telegraph  station 


io6 


Radio  Broadcast 


THE  WIRELESS  TOWERS  AND  RECREATION  BUILDING  AT  CAMP  WALLKILL,  NEAR  LAKE  MOHAWK,  N.  Y. 


Membership  in  this  club  became  in  the  boys' 
eyes  a  desirable  goal.  Not  every  boy  was  per- 
mitted to  join  it.  You  had,  first  of  all,  to 
know  quite  a  bit  about  the  principles  of  wire- 
less. Two  years  ago  the  membership  was 
somewhat  limited  but  last  year  about  half  the 
boys  in  camp  belonged  to  the  club. 

There  are,  no  doubt,  many  people  who  would 
like  to  know  how  this  radio  club  functions. 
The  following  details  were  related  to  me  by 
Martin  Walter,  Jr.,  who  has  been  actively 
engaged  in  wireless  work  at  Dudley  for  a  num- 
er  of  years,  first  as  a  boy  in  camp  and  later  as 
an  assistant  to  the  director.  It  is  commonly 
the  custom  at  Dudley  for  many  of  the  boys  to 
come  back  to  camp  season  after  season,  and 
then  when  they  reach  college  age  some  of  them 
become  assistants  to  the  director.  Mr.  Walter 
says: 

"Our  radio  club  at  camp  is  governed  by  what 
we  call  the  'radio  committee'.  This  consists  of 
about  six  of  us  who  have  been  interested  in  wire- 
less work  for  several  years.  We  all  have  gov- 
ernment licenses  and  consequently  know  the 
code  well  enough  to  receive  press  dispatches 
every  evening.  Last  summer,  however,  this 
was  not  necessary,  as  the  broadcasting  stations 


furnished  most  of  the  matter  we  were  inter- 
ested in.  This  was  mainly  baseball  scores,  the 
weather  for  our  section,  correct  time,  and  even 
stock  reports  which  some  of  the  older  fellows 
were  interested  in.  As  soon  as  the  news  was 
received  it  was  neatly  typed  and  posted  on  the 
'radio  bulletin'  which  occupied  a  prominent 
place  on  the  wall  of  our  dining  hall.  Music 
was  also  received  every  evening  and  this 
brought  quite  a  crowd  of  listeners  to  the 
'shack.' 

"We  had  a  small  transmitting  set  and  under 
favorable  conditions  we  could  talk  with  fellows 
in  New  York  City.  However,  we  had  a 
regular  daylight  schedule  arranged  with  an 
amateur  in  Albany  (about  150  miles)  and  an- 
other with  the  University  of  Vermont,  Burling- 
ton (about  50  miles).  By  relaying  to  these 
stations,  messages  were  sent  home  by  the  fel- 
lows. One  of  the  committee  was  supposed 
to  be  in  the  shack  all  the  time,  and  he  was 
responsible  for  the  apparatus.  Any  one  could 
come  in  and  work  the  receiving  set,  provided 
the  consent  of  the  man  in  charge  was  obtained, 
but  only  fellows  holding  transmitting  licenses 
were  permitted  to  use  the  sending  set. 

"The  men  on  the  committee  were  not 


Radio  in  Summer  Camps 


107 


allowed  to  serve  as  officers  of  the  club  but 
assumed  a  position  something  similar  to  a 
board  of  directors.  Elections  were  held  by 
ballot  for  the  officers.  We  had  no  dues,  as  the 
camp  supplied  everything.  The  regular 
meetings  of  the  club  were  held  on  Sunday  after- 
noons. All  boys  in  camp  were  welcome  to 
attend  and  a  good  many  became  interested 
in  this  way. 

"After  the  roll  call,  one  of  the  committee 
generally  gave  a  talk  on  constructing  sets — 
how  they  worked — and  simple  theory.  We 
were  lucky  last  summer  in  having  at  camp  a 
Navy  operator  and  he  gave  talks  on  his  ex- 
periences which  were  always  very  interesting 
and  well  received.  Occasionally,  a  visitor  came 
up  who  had  had  some  experiences  and  he  was 
never  allowed  to  get  away  without  giving  a 
talk. 

"After  the  meeting  was  over,  the  committee 
was  always  on  hand  to  answer  any  questions, 
and  you  may  be  sure  there  were  enough  to  keep 


us  busy.  We  also  had  code  classes  twice  a 
week.  These  did  not  work  out  quite  so  well, 
probably  because  the  fellows  were  too  young 
to  be  interested  in  that  end  of  it.  After  a  whole 
summer  of  practising,  a  few  fellows  got  enough 
speed  to  take  the  license  exam,  when  they  got 
back,  and  the  rest  of  them  knew,  at  least,  that 
there  was  a  code. 

"For  the  first  time,  last  year,  we  started  mak- 
ing sets.  This  took  very  well  and  several  sets 
were  finished  at  camp  and  a  number  more  were 
in  the  'all  but'  stage.  This  idea  was  started 
late  in  the  season,  or  more  would  have  been 
constructed.  We  drew  up  plans  for  a  standard 
set  costing  about  twenty  dollars  and  any  one 
wanting  to  make  it  had  to  have  his  parents' 
consent.  After  determining  the  number,  a 
bulk  order  was  sent  to  a  firm  in  New  York  and 
in  this  way  a  discount  was  obtained.  After  the 
parts  arrived  the  sets  were  made  in  the  shop  and 
tried  out  in  connection  with  the  regular  camp 
set." 


72%  OF  THE    1922  CAMP  WALLKILL  BOYS  CONSTRUCTED  SETS 

The  radio  workshop  where  boys  are  given  instruction  in  building  their  own  apparatus.  Five  of  last  summer's  campers 
passed  the  government  requirements  and  obtained  operating  licenses,  through  the  training  they  received  at  camp 


Operating  a  Loud  Speaker  on  One 
Tube,  Without  Batteries 


By  WALTER  VAN  B.  ROBERTS 

Princeton  University 


^  HOSE  who  are  fortunate  enough 
(from  the  present  point  of  view)  to 
have  1 10  volts  direct  current  available 
at  every  lamp  socket  will  find  the 
receiver  described  below  to  have  the 
advantages: 


followin 

1.  It  uses  no  bat- 
teries of  any  kind,  thus 
eliminating  all  battery 
cost  and  upkeep. 

2.  It  makes  use  of 
a  loop  aerial,  which 
saves  the  trouble  of 
stringing  an  aerial  and 
allows  the  receiver  to 
be  set  up  at  any  place 
in  the  house  where  a 
lamp  socket  is  handy. 

3.  The  output  is 
great  enough  so  that 
local  stations  (say  up 
to  25  miles)  can  be 
heard  satisfactorily 
over  a  good-sized 
room. 


4.  In  operating, 
only  two  adjustments 
are  really  necessary,  and  neither  of  these  is 
difficult  to  make. 

5.  The  cost  of  the  parts  is  small,  compared 
to  the  cost  of  parts  that  would  be  required  to 
get  the  same  volume  out  of  the  loud  speaker  by 
any  other  means  using  a  loop  aerial. 

6.  Only  one  vacuum  tube  is  required. 
There  are  disadvantages  also: 

1 .  The  set  cannot  be  relied  upon  for  satis- 
factory loud-speaker  results  from  distant  sta- 
tions, although  on  some  nights  distant  stations 
can  be  heard  surprisingly  well. 

2.  The  quality  is  not  so  good  as  that  ob- 
tainable by  other  means.  There  is  the  very 
high  weak  whistle  of  the  interruption  frequency 
of  the  super-regenerative  circuit,  and  if  the 
signal  is  very  weak  a  certain  amount  of  hissing 
noise  develops  in  the  circuit  itself.  However, 


Mr.  Roberts,  who  is  engaged  in  research 
work  at  the  Palmer  Physical  Laboratory, 
Princeton,  N.  J.,  has  been  experimenting  for 
some  months  with  various  systems  of  reception 
employing  a  single  tube.  His  article,  "A 
Single-Tube  Loop  Set  in  a  Brief-Case,"  which 
was  published  in  Radio  Broadcast  last 
month,  describes  a  receiver  weighing  only  six 
pounds,  including  everything.  Although  Mr. 
Roberts'  claims  for  this  portable  set  are  very 
conservative,  many  readers  have  apparently 
become  so  enthusiastic  that  they  are  building, 
or  planning  to  build,  similar  outfits  for  use  this 
summer. 

The  batteryless  loop  outfit  described  this 
month  will  undoubtedly  make  a  similar  appeal 
to  those  who  have  long  been  wanting  a  loud- 
speaker set  which  could  be  operated  on  a  loop 
without  necessitating  a  prohibitive  outlay  of 
capital. — The  Editor. 


if  the  signal  is  fairly  strong,  the  quality  is  good 
enough  for  all  practical  purposes. 

3.  It  is  not  very  selective.  This  is  one  rea- 
son why  distant  stations  are  hard  to  get.  How- 
ever, there  is  no  difficulty  in  separating  the  360- 

from  the  400 -meter 
stations,  even  if  the 
one  to  be  excluded  is 
only  a  few  miles  away. 

On  the  whole,  it  is 
probably  the  most 
practical  arrangement 
at  present  available  for 
those  who  want  loud- 
speaker results  with 
no  upkeep  cost  or 
bother  with  battery 
charging,  who  are  sat- 
isfied with  the  pro- 
grams of  local  stations, 
and  who  have  the  nec- 
essary direct  current 
supply. 

On  page  1 1  o  is  shown 
the  circuit,  which  is 
seen  to  be  the  one 
made  public  by  Arm- 
strong except  for  the  rearrangements  which 
are  necessary  in  order  to  avoid  using  batteries, 
and  the  addition  of  the  fixed  .0005  mfd.  con- 
denser which  seems  to  make  the  circuit  easier 
to  operate.  The  2  mfd.  condenser  and  the 
high-tension  winding  of  the  Ford  spark  coil  are 
not  necessary — they  were  put  in  to  keep  the 
direct  current  out  of  the  loud  speaker  windings 
and  thus  avoid  all  chance  of  overheating  them. 

The  filament  current  is  limited  to  the  desired 
value  by  making  a  proper  combination  of  or- 
dinary electric  lights  connected  in  parallel. 
A  single  100-watt  light  will  probably  pass 
enough  current  for  the  filament  of  a  216-A  tube. 
A  100-watt  light  with  a  25- or  even  a  1  5 -watt 
light  in  parallel  will  be  enough  for  a  VT-2  tube. 
A  single  25-watt  lamp  is  as  much  as  can  be  used 
with  a  Radiotron  UV-201-A  or  a  Cunningham 


Operating  a  Loud  Speaker  on  One  Tube,  Without  Batteries 


MR.  ROBERTS  BATTERYLESS  LOOP  SET 
The  filament  and  plate  currents  are  supplied  from  the  ordinary  D.  C.  house  lighting  circuit,  i  and  2,  75-turn  multilayer 
coils;  3,  Western  Electric  VT-2  tube;  4,  4-6  ohm  rheostat;  5,  .05  mfd.  telephone  shunt  condenser;  6,  1250-turn  multilayer 
coil,  shunted  by  a  .001  mfd.  condenser  (7);  8,  100-watt  electric  lamp;  9,  25-watt  lamp;  10,  .0005  mfd.  variable  condenser; 
ir,  switch  for  turning  on  and  off  the  110-volt  supply;  12,  .002  mfd.  condenser  across  the  1500-turn  multilayer  coil  (14); 
13,  lamp  socket  which  feeds  the  110-volt  current  into  the  set;  15,  .0005  mfd.  condenser,  connected  directly  across  the 
interruption  frequency  circuit;  16,  2  mfd.  condenser  in  series  with  the  loud  speaker;  17,  Ford  spark-coil,  the  secondary  of 

which  is  used  as  a  choke  coil 


C-301-A.  It  is  not  a  bad  idea  to  use  a  carbon 
filament  lamp  for  the  ioo-watt  lamp  because 
carbon  has  a  high  resistance  when  cold  and  so 
gives  the  effect  of  turning  the  current  on 
slowly.  The  variable  resistance  is  an  ordinary 
filament  rheostat  and  is  used  to  get  a  negative 
potential  for  the  grid.  It  has  very  little  effect 
upon  the  filament  current. 

ABOUT  THE  LOUD-SPEAKER 

WESTERN  Electric  VT-2  tubes  (also  called 
"E"  tubes)  have  proven  very  satisfac- 
tory. The  Western  Electric  2 1 6-A,  used  in  that 
company's  power  amplifier  should  be  equally 
good.  A  Radiotron  201 -A  or  Cunningham 
C-301-A  tube  will  work  well  with  head  phones 


but  will  probably  not  give  enough  volume  for 
the  loud  speaker.  If  the  Western  Electric 
10-D  loud  speaker  is  used  with  the  above 
mentioned  W.  E.  tubes,  the  transformer  in  the 
base  should  be  disconnected,  which  makes  it 
equivalent  to  the  5  18-W  loud  speaker,  which  is 
the  type  supplied  with  the  power  amplifier. 

For  any  one  who  likes  to  build  apparatus  and 
knows  anything  about  radio,  the  foregoing  re- 
marks are  sufficient.  He  can  wind  spider-web 
coils  to  avoid  buying  the  small  multi-layer  coils 
and  he  can  improvise  his  own  means  of  varying 
the  mutual  inductance  between  both  sets  of 
coils.  The  writer  prefers  to  spread  all  the  parts 
out  on  a  flat  board  where  it  is  all  in  sight 
(though  rather  unsightly!)  and  to  vary  mutual 


1  IO 


Radio  Broadcast 


inductances  by  the  simple  process  of  sliding  the 
coils  around  by  hand. 

For  the  benefit  of  any  one  wanting  to  try  out 
this  circuit  without  bothering  to  make  up  any 
parts  or  figuring  out  his  own  way  of  mounting 
them,  the  following  instructions  are  given.  It 
is  assumed  that  the  conventional  arrangement 
on  the  back  and  front  of  a  panel  is  desired. 
The  constants  of  the  circuit  are  the  same  as 
used  by  the  writer  for  the  past  six  months. 
They  are  satisfactory;  but  probably  not  the 
best:  for  instance,  the  Ford  coil  arrangement 
could  be  replaced  with  advantage  by  a  prop- 
erly designed  step-down  transformer. 

A  list  of  parts  to  be  bought  is  as  follows: 

One  tube 
One  socket 

One  filament  rheostat,  4  or  6  ohms 
Four  sockets  for  ordinary  electric  lights 
One  Ford  spark  coil  or  any  other  audio-frequency 
choke  coil 

One  fixed  condenser,  capacity  2  microfarads 
One  fixed  condenser,  capacity.05  mfd  (a  Federal 
costs  $.50) 

Three  fixed  condensers  such  as  Micadons,  of  capa- 
cities .0005,  .001  and  .002  mfd 

One  Dubilier  variable  condenser,  .0005  or  .001 
mfd.  maximum. 

Two  multilayer  coils  of  75  turns  each 

One  multilayer  coil  of  1250  turns 

One  multilayer  coil  of  1500  turns 

Two  double-coil  mountings  for  these  coils 

One  loud  speaker 

One  loop  aerial  of  about  twice  as  many  turns  of 
wire  as  usually  used  on  radio-frequency  ampli- 
fier'sets. 

One  panel  of  any  insulating  material,  7"  by  16" 
or  more 

One  cabinet,  or  brackets  to  support  panel 


Supply  of  binding  posts,  Fahnestock  clips,  screws, 
wire,  etc. 

CONSTRUCTION  DATA 

ON  THE  front  of  the  panel  (allowing  a  little 
space  around  the  edges  if  it  is  to  go  in  a 
cabinet)  mount: 

In  the  centre,  along  the  upper  edge,  three 
electric  light  sockets  sufficiently  spaced  so  that 
a  100-watt  light  will  go  in  alongside  another 
light. 

1  n  the  centre,  at  the  bottom,  the  variable  con- 
denser, the  whole  thing  being  mounted  on  the 
front  of  the  panel  as  this  Dubilier  "Variadon" 
is  very  thin. 

At  the  bottom,  to  the  left  of  the  condenser, 
the  knob  of  the  rheostat,  which  is  preferably 
behind  the  panel.  The  rheostat  may  be  turned 
into  the  "off"  position  in  lieu  of  a  switch  when 
not  using  the  set. 

At  the  bottom,  to  the  right  of  the  condenser, 
an  electric  light  socket  into  which  the  plug 
carrying  the  110-volt  supply  will  be  screwed 
when  operating  the  set. 

In  the  upper  left  and  upper  right  hand 
corners,  the  two  double-coil  mountings,  each 
being  mounted  so  that  the  movable  coil 
swings  sideways  away  from  the  centre  of  the 
panel. 

On  the  left  edge,  near  the  bottom,  two  bind- 
ing posts  or  clips  for  the  loop. 

On  the  right  edge,  near  the  bottom,  two  posts 
or  clips  for  the  loud  speaker  or  phones. 

Behind  the  panel,  mount: 

The  vacuum  tube  socket,  just  above  the 
rheostat,  being  careful  that  the  position  is  such 
that  the  filament  won't  sag  toward  the  grid. 


c 


LAMP  SOCKETS 


.002 


D 


2  MFDS. 


.05  MFD. 


AUDIO  FREQ. CHOKE 
FORD  COIL  SEC. 


110  VOLT  LIGHTING  CIRCUIT 


THE  CIRCUIT  ARRANGEMENT  FOR  THE  ONE-TUBE  LOUD  SPEAKER  LOOP  RECEIVER 
A  and  C  are  75-turn  multilayer  coils;  B  is  a  1250-turn  coil  and  D  a  1500-turn  coil 


Operating  a  Loud  Speaker  on  One  Tube,  Without  Batteries 


1 1  i 


Behind  the  right  hand  side  of  the  panel, 
the  Ford  coil,  the  2  mfd,  and  .05  mfd.  con- 
densers, in  any  convenient  arrangement. 

The  small  Micadons  can  be  supported  in 
mid-air  by  the  wiring  if  it  is  stiff,  or  if  any 
experimentation  with  different  values  is  desired, 
they  can  be  sprung  between  two  Fahnestock 
clips  whose  flexible  parts  are  flattened  out  and 
bent  to  stand  out  perpendicularly  from  the 
panel. 

HOW  TO  MAKE  IT  "COOK" 

THE  wiring  can  be  readily  done  by  follow- 
ing the  diagram,  but  even  if  this  is  done 
without  error,  there  is  only  one  chance  in  four 
that  the  set  will  work — at  the  first  try.  If  it 
doesn't,  swing  both  movable  coils  out  as  far  as 
they  will  go,  set  the  condenser  at  maximum, 
and  touch  both  leads  to  the  loop.  If  no  click 
or  very  faint  high  whistle  is  heard,  the  110- 
volt  circuit  is  connected  the  wrong  way 
around.  This  is  easily  remedied  by  reversing 
the  points  of  the  plug.  Next,  set  the  condenser 
at  about  half  its  maximum  value  and  slowly 
move  the  tickler  coil  in.    If  a  hissing  noise  is 


not  heard,  the  tickler  coil  is  connected  back- 
ward and  the  connections  to  it  must  be  inter- 
changed. Finally,  when  signals  have  been  ob- 
tained with  the  1 500-turn  coil  swung  way  out, 
see  if  any  improvement  can  be  effected  by 
bringing  it  in  slightly.  If  not,  reverse  the 
connections  to  this  coil  also  and  thus  find  out 
which  way  it  works  best.  (It  is  assumed  that  the 
tickler  coil  and  the  1 500-turn  coil  are  the  ones 
that  have  been  mounted  on  the  movable  parts 
of  the  two-coil  mountings.) 

In  operating  this  receiver,  it  may  happen 
that  when  the  tickler  coil  is  brought  in  too 
close,  the  circuit  will  suddenly  go  dead.  In 
that  case,  swing  the  tickler  away  a  little  and 
touch  one  of  the  leads  to  the  loop.  A  very 
little  practice  will  make  any  one  familiar  with 
the  tuning  of  the  set. 

In  concluding,  the  writer  wishes  to  repeat 
that  he  is  only  giving  values  of  capacities,  coils, 
etc.,  that  have  worked,  and  that  a  few  turns  less 
on  the  tickler  coil  or  loop,  or  a  rearrangement 
of  the  coils  and  condensers  in  the  interruption 
circuit,  or  a  different  kind  of  tube,  may  bring 
about  improved  results. 


A  CORNER  OF  THE  OFFICE  OF  RADIO  BROADCAST,  SHOWING  APPARATUS  TO  BE  TRIED  OUT 
It  is  our  practice  to  test  new  circuits  and  new  devices  before  recommending  them  to  you 


A  Stormy  P.  M.  at  Alice's 


By  WILLARD  WILSON 


HAD  come  to  call  on  Alice,  and  we  were 
taking  our  tea  with  animal  cookies — that 
is,  she  was.  I  was  taking  the  cookies 
alone.  I  have  always  hated  tea,  it  has 
such  a  slimy,  greenish  taste. 
Alice  had  devoured  a  great  amount  of  cookies 
and  tea,  and  I  had  imbibed  a  fairly  large  herd  of 
animals,  but  still  the  small  tea  talk  wouldn't 
come.  The  atmosphere  was  getting  horribly 
tense — you  know — the  way  it  is  when  a  thunder 
storm  is  coming,  and  the  static  begins  to  buzz 
and  whoop  in  your  phones.  Already  I  could 
see  the  preliminary  flashes  of  lightning  from 
Alice's  eyes,  and  I  began  involuntarily  to  cringe 
and  try  to  appear  humble — and  take  it  from 
me,  that  is  not  a  hard  job  when  Alice  is  about. 

I  had  a  pretty  good  idea  of  the  cause  of  the 
oncoming  tempest — 1  hadn't  been  up  to  see  her 
or  take  her  anywhere  for  a  whole  week. 
Heaven  knows  it  wasn't  my  fault!  1  have  a 
new  Armstrong  set  and  I  had  been  mothering 
it  for  six  days  like  an  old  hen,  trying  to  get  the 
blame  thing  to  perk. 


I  MANAGED  TO  STAVE  OFF  MY  FATE  A  LITTLE  LONGER 
BY  SWALLOWING  A  COW,  A  DONKEY,  AND  TWO  DOGS 


But  about  Alice.  She  began  by  gazing 
thoughtfully  at  the  tips  of  her  little  shoes. 
Carefully  she  beheaded  an  elephant,  then 
washed  down  the  carcass  with  a  draught  of  tea. 
Eventually  she  looked  at  me. 

"  Willy  " — she  knows  1  hate  that  name  above 
all  others — "Willy,  where  have  you  been  all 
week?"  Her  voice  was  soft  and  cooing — it 
always  is — but  I  quailed. 

"Oh,  I've  been  pretty  busy  " 

"Why,  Willy!"  She  interrupted  my  non- 
chalant tone  with  an  incredulous  cry.  "  I 
thought  you  were  having  your  vacation!" 

I  began  to  sweat  a  little  at  that,  but  managed 
to  stave  off  my  fate  a  little  longer  by  swallowing 
a  cow,  a  donkey,  and  two  dogs.  (It's  funny 
that  there  are  always  more  dogs  in  animal 
cookies  than  any  other  beast.)  At  the  end 
of  that  operation  I  had  concluded  that  the 
quickest  way  out  for  me  would  be  to  tell 
the  truth. 

"Alice   dear — "    I    began   bravely.  But 
she  cut  me  off  short.    The  storm  had  burst 
and  she  was  in  the  first  stage, 
where  they  get  defiant. 

"Don't  'dear'  me!" — she 
said  savagely.  "  If  you  don't 
care  enough  to  come  around 

once  in  a  while  " 

Here  I  interrupted  her. 
"Now,  Alice,  please  don't  raise 
a  row  until  you  know  what  it's 
about."  I  was  resolved  to  have 
at  least  a  hearing,  though  I 
was  perfectly  aware  that  it 
would  make  not  the  slightest 
difference  to  her  what  it  was 
about. 

"  I  just  got  a  new  radio  set," 
I  explained  carefully.  She 
nodded  her  head  viciously.  I 
really  believe  she  already  knew 
it.  But  1  went  on  patiently 
describing  the  weary  hours  1 
had  spent  tuning  and  experi- 
menting—  1  tried  to  make  it 
all  sound  very  important — and 
then  I  began  to  discuss  its 
merits.    I  had  it  going  great 


A  Stormy  P.  M.  at  Alice's 


"3 


just  the  night  before,  so  I  guess  maybe  I  did 
get  a  little  over-enthusiastic. 

"Why,"  I  told  her  proudly,  "Some  day  I 
expect  to  be  able  to  hear  program  broad- 
casted from  clear  across  the  continent,  then 
across  the  ocean,  and  then — "  I  became  aware 
that  she  was  not  sharing  my  jubilation.  In- 
deed, 1  saw  that  she  was  almost  ready  for  the 
next  stage.  Her  lip  was  beginning  to  tremble. 
That  scared  me.  I  haven't  lived  this  long 
without  learning  some  of  the  signs,  and  1  simply 
cannot  be  brave  in  the  face  of  hysterics.  It 
makes  me  feel  like  a  murderer  or  something. 
1  never  can  tell  what  1*11  do  when  a  girl 
begins  to  cry. 

"Now,  now,"  I  said,  soothingly,  panic  tug- 
ging at  my  heart.  Nervously  I  patted  her 
hair.  She  has  wonderful  hair — so  soft — and 
with  a  fresh,  sweet  smell  like  new-mown  hay. 
Yes,  it's  bobbed.  I  don't  know  whether 
that  is  what  makes  the  new-mown  smell  or 
not.  But  she  wasn't  quite  ready  to  be  soothed 
yet. 

"  B — Bill,"  she  went  on  in  that  brave,  plucky 
way  she  has — as  if  it  is  breaking  her  heart  and 
yet  she  must  finish  what  she  has  started — 
"after  we  are  married,  and  getting  o — old" — 
she  moaned  dismally — "will  you  spend  all  of 
your  time  listening  to  some  old  pup-pup- 
program?  "  She  gulped  convulsively  and  looked 
up  at  me. 

Before  1  could  answer,  she  presented  her 
conclusive  argument.  She  (speaking  vapori- 
cally)  switched  her  condenser.  It  is  wonderful 
the  amount  of  moisture  and  weeping  that  can 
come  from  two  big,  pleading  eyes.  I  knew  it 
would  get  me — it  always  does.  In  a  moment 
all  I  could  think  of  was  how  I  could  stop  her 
crying.  Frantically  I  racked  my  fevered 
brain  for  some  new  scheme,  but  before  I  had 
decided  on  any  definite  plan  of  action  she  was 
going  again. 

"  B — Bill,"  she  sobbed,  "w-will  you  promise 
never  to  neglect  m-me  again  for  that — that  old 
radio?" 

"Yes!  Yes!" — I  promised  wildly,  dis- 
tracted by  her  suffering,  "I'll  never  look  at  a 
B  battery  again.  I'll  throw  my  phones  out  of 
the  window.-  I'll  smash  up  my — "  She  put 
her  arm  around  my  neck  and  cuddled  down  in 
my  arms.  I  stopped  .  my  resolutions  with  a 
sigh  of  relief.    I  knew  that  the  storm  was  over, 


WOMEN   ARE  SO  BLAMED  INCONSISTENT 


and  somehow  felt  that  I  had  gone  a  bit  too  far 
on  the  swearing  off  as  it  was. 

A  few  moments  later  she  lifted  her  rumpled 
head  from  my  arms.  "  Billy  dear,"  she  said 
softly,  "did  you  say  it  was  an  Armstrong  set?" 

"Yes,"  I  answered,  "an  Armstrong  Super." 

"Is  it  made  by  the  same  company  that 
makes  Armstrong  baking  soda?" — she  wanted 
to  know. 

I  had  never  heard  the  names  of  the  different 
kinds  of  baking  soda — in  fact  I  never  even 
worked  as  a  cook — and  that  question  stumped 
me.  I  slowly  swallowed  a  horse  and  a  camel, 
then,  like  a  true  Californian,  began  to  talk  of 
the  weather. 

Alice  didn't  insist  on  an  answer  and  in  about 
three  minutes  she  was  as  cool  and  sweet  as  a 
marshmallow  sundae.  She  poured  herself 
another  cup  of  tea  as  if  nothing  in  the  world 
had  happened — just  after  we  had  finished  a 
scrap  that  could  easily  have  turned  our  lives 
into  different  channels. 

That's  the  dickens  of  it.  Women  are  so 
blamed  inconsistent!  Alice  was  up  at  our 
house  last  night,  and  she  wouldn't  even  take 
the  receivers  from  her  ears  long  enough  for  me 
to  cut  in  on  Arlington  for  the  time  signals. 


Learning  the  Code 


Why  All  New  Recruits  to  the  Radio  Game  Will  Find  It  Worth  While  to  Learn  the 
Radio  Telegraph  Code.  How  to  Memorize  the  Alphabet,  and  How  to  Train 
Your  Ear.    Tips  on  Copying  Code.    The  Use  and  Abuse  of  the  Sending  Key 

By  WILLIAM  HARRIS,  JR. 


YOU  are  one  of  these  out-and-out 
enthusiasts,  let  us  say,  who  falls 
under  the  general  head  of  broad- 
cast listener.  Whether  you  are 
the  kind  of  B.  C.  L.  who  will  sit 
for  hours  enjoying  the  local  programs,  or  (the 
other  extreme)  the  kind  who  no  sooner  bags 
one  brace  of  station  calls  than  he  is  off  on  a  hunt 
for  more  elusive  game,  is  immaterial:  you 
have  a  set  and  you  think  radio  is  great  stuff 
and  you  want  the  ether  waves  to  talk  to  you. 

No  doubt  you  have  noticed  that  there  are 
other  stations  in  the  air  besides  those  that  do 
the  broadcasting.  If  you  tune  down  below  the 
concert  range  to  200  meters,  you  will  be  regaled 
with  all  sorts  of  interesting  and  unintelligible 
sounds,  ranging  in  character  from  the  growl 


of  a  bulldog  to  the  whistle  of  a  peanut-roaster. 
These  sounds  would,  of  course,  be  far  more 
interesting  if  they  were  intelligible — to  you. 
You  might  listen  to  an  amateur  in  Florida 
chewing  the  rag  with  a  comrade  up  in  Michigan 
whom  he  has  known  on  the  air  for  five  or  six 
years  but  has  never  seen.  You  might  hear 
two  fellows  in  neighboring  towns  come  back 
and  forth  at  each  other  almost  as  quickly  as 
they  could  use  the  telephone,  discussing  some 
new  hook-up,  telling  stories,  or  speculating  as 
to  the  duration  and  intensity  of  the  heat  wave 
that's  passing  through  the  town  where  one 
station  is  located  on  its  way  toward  the  other, 
or  aiding  in  the  relay  of  a  message  from  the 
Atlantic  coast  to  the  Pacific. 

Then  go  up  to  600  meters,  if  your  broadcast 


AN  AUTOMATIC  SENDER  IS  A  GREAT  HELP  TO  THE  WOULD-BE  TELEGRAPHER 
He  can  turn  it  on  at  any  time  and  receive  code  messages  at  any  speed.    This  boy  uses  either  the  hand-key  or  the  machine 
to  operate  the  small  buzzer  shown  on  the  key  baseboard.    By  comparing  his  own  sending  with  the  smooth,  perfect  sending 
of  the  machine,  he  is  able  to  improve  his  own  "fist"  very  quickly 


Learning  the  Code 


i  '5 


receiver  will  tune  that  high,  and  listen  to  the 
whines  or  the  musical  notes  of  the  ship  stations. 
If  you  could  read  code  even  at  the  rate  of 
twelve  words  a  minute,  you  might  learn  that 
that  booming  spark  signal  is  advising  the 
owners  of  S.  S.  So-and-so  that  their  vessel  is 
delayed  six  hours  on  account  of  heavy  fogs  but 
will  reach  port  in  the  morning.  Or  the  musical 
note  may  carry  a  radiogram  from  a  passenger  re- 
turning from  Europe  to  his  family:  "Back  to 
God's  country  to-morrow  tell  Mary  to  make  one 
of  her  old-fashioned  rice  puddings  love,  Ed." 
You'd  be  surprised 
what  choice  bits  a 
businesslike  flock  of 
radio  code  signals 
sometimes  carries! 

The  amateur  and 
ship  traffic  is  not  all 
that  is  of  interest,  by 
any  means.  Of 
course,  your  broad- 
cast set  will  not 
take  you  up  into  the 
realm  of  the  transat- 
lantic stations — the 
high-power  fellows 
that  come  in  on  a 
long-wave  receiver 
clear  and  loud  with  a 
single  tube.  Your  360 
to  400-meter  outfit 
won't  even  go  up  near 

NAA's  (Arlington's)  transmission  of  time 
signals  (12  noon  and  10  p.  m.),  weather  forecasts 
and  news  from  all  over  the  world.  But  once 
you  have  learned  the  code,  you  will  probably 
want  to  buy,  or  assemble,  yourself,  a  receiver 
for  the  longer  waves. 

Nor  is  listening-in  on  the  world  the  only 
reason  why  it  will  be  worth  your  while  to  learn 
the  code.  Thousands  of  amateurs  will  testify 
that  the  best  sport  of  all  is  carrying  on  two-way 
conversations  with  other  "hams."*  You  may 
not  care  to  undertake  anything  as  pretentious 
as  the  installation  of  a  station  with  a  500- 
mile  transmitting  range;  but  with  a  single  tube 
and  a  simple  home-built  set  you  can  call  up  a 


*  Those  who  are  interested  in  building  their  own  trans- 
mitting sets  will  be.  interested  in  the  series  of  articles  by 
Zeh  Bouck,  "Simple  Bulb  Transmitters,"  which  appeared  in 
Radio  Broadcast  from  November,  1922  to  March,  1923, 
inclusive.  For  a  low-power,  inexpensive  and  ingenious 
arrangement,  see  'Transmitting  and  Receiving  with  the 
Same  One-Tube  Set"  by  Frederic  W.  Proctor  in  the 
May,  1923,  number. 


How  to  Get  Your  Transmitting 
Licenses 

If  you  wish  to  transmit,  you  must  have  two 
licenses,  one  certifying  you  as  an  operator,  the 
other  for  your  station.  You  must  be  able  to 
receive  at  least  ten  words  a  minute  (five  letters 
or  characters  to  the  word),  and  must  comply 
with  certain  other  requirements  explained  in 
the  Government  pamphlet:  "Radio  Com- 
munication Laws  of  the  United  States."  It  is 
advisable  to  obtain  this  pamphlet,  as  it  gives 
a  list  of  places  where  examinations  are  held 
and  other  information  either  necessary  or 
helpful  to  the  prospective  operator.  It  may 
be  had  from  the  Superintenent  of  Documents, 
Government  Printing  Office,  Washington, 
D.  C.    Price,  15  cents  a  copy. 


friend  who  has  a  similar  outfit  down  the  other 
end  of  the  street,  or  over  in  the  next  town. 

But  enough  of  this.  If  you  are  still  uncon- 
vinced that  learning  the  code  will  open  a  great 
new  field  of  interest  and  enjoyment  to  you, 
just  ask  some  dyed-in-the-wool  amateur 
whether  he's  glad  be  learned  it. 

HOW  TO  ACQUIRE  THE  CODE 

BEFORE  attempting  to  do  any  receiving 
at  all,  you  should  memorize  the  code 
equivalents  for  every  one  of  the  twenty-six 

letters  of  the  alphabet 
— memorize  them  so 
that  you  can  lay  the 
edge  of  a  card  over 
the  code  symbols  on 
page  116,  leaving 
the  letters  showing, 
and  repeat  to  yourself 
correctly  each  letter, 
checking  up  each  time 
by  looking  at  the  cor- 
rect code  equivalent. 
Take  a  few  letters  first 
— f or  example,  A 
through  F — and  "get 
these  down  cold."  It 
is  easy  to  improvise 
simple  ways  of  associ- 
ating, in  your  mind, 
each  combination  of 
dots  and  dashes  with 
its  letter,  ways  which  will  last  you  until  the  code 
is  ringing  in  your  head,  until  means  B 

immediately,  not  "dash,  three  dots."  Leave 
these  six  letters  and  take  the  letters  from  G 
through  M.  Then  review  what  you  have 
memorized  so  far  and  you  will  have  learned 
thirteen  letters — half  the  alphabet!  If  you 
are  exceptionally  keen,  and  buckle  right  down 
to  the  job,  half  an  hour's  study  will  give  you 
all  the  letters;  and  even  if  you  are  only  an 
ordinary  mortal,  like  the  rest  of  us,  you  should 
not  need  more  than,  say,  three  or  four  periods 
of  study  of  a  half  hour  each. 

When  you  have  no  one  to  help  you,  here  is  an 
excellent  way  of  drilling  the  code  into  your 
memory :  cover  over  the  code  symbols  in  the  list 
and  ask  yourself  what  A  is,  what  B  is,  etc. 
Each  time  you  don't  know,  write  the  letter  you 
missed  on  a  slip  and  turn  it  face  down:  if  you 
can't  think  what  F  is,  for  instance,  put  an  F 
slip  aside.  (It  might  be  well  also  to  put  aside 
one  whole  alphabet.)    Then  draw  your  slips, 


Radio  Broadcast 


INTERNATIONAL  MORSE  CODE  AND  CON- 
VENTIONAL SIGNALS 


A  (German)  .   .  

A  or  A  (Spanish-Scandinavian) 

CH  (German-Spanish) 


E  (French)  . 
N  (Spanish) 
O  (German) 
U  (German) 


1  . 

2  . 

3  . 

4  . 

5  . 

6  _ 

7  - 

8  _ 

9  - 
0  - 


Period  

Comma   . 

Interrogation  _ 

Exclamation  point   . 

Bar  indicating  fraction    

Parenthesis    .   

Distress  call   

Attention  call  to  precede  every  transmission  ....   . 

General  inquiry  call,  (C  Q)    .   .  .   . 

From  (de)   

Invitation  to  transmit  (go  ahead)  (K)  

Question  (please  repeat  after  interrupting  long  . 

messages)  -  _ 


Wait  (AS)  

Break  (Bk.)  (double  dash) 

Understand  

Error  

Received  (O.  K.)   


Position  report  (to  precede  all  position  messages) 

(TR)  

End  of  each  message  (cross)  


Transmission  finished  (end  of  work)  (conclusion  of 

correspondence)   .  

1.  A  dash  is  equal  to  three  dots. 

2.  The  space  between  parts  of  the  same  letter  is  equal  to  one  dot. 

3.  The  space  between  two  letters  is  equal  to  three  dots. 

4.  The  space  between  two  words  is  equal  to  five  dots. 


one  by  one.  If  you  know  them  all,  well  and 
good;  if  not,  learn  the  letters  you  missed,  then 
and  there,  and  put  those  slips  aside  to  form 
a  new  pile.  By  this  process  of  running  over 
and  over  the  letters  you  don't  know,  you  will 
arrive  at  about  half  a  dozen — J,  Q,  X,  and  Z 
will  probably  be  among  them — which  will 


represent  your  temporary  Waterloos.  Go  at 
these  few,  and  get  them — till  you  know  them  as 
well  as  you  know  A  and  E.  Following  this, 
review  the  whole  alphabet  once  or  twice  and 
call  it  a  day.  But  keep  the  slips  for  the  next 
set-to.  They  may  seem  like  a  reversion  to 
kindergarten  days;  but  they  can  help  you 


Learning  the  Code 


"7 


a  great  deal.  The 
principal  advan- 
tage this  system  has 
over  any  hit-or-miss 
method  is  that  you 
learn  the  so-called 
"difficult"  letters 
thoroughly.  Later 
on,  when  you  hear 

you  won't  men- 
tally curl  up  and 
die,  as  so  many  be- 
ginners do,  missing 
the  next  four  or  five 
letters  before  you 
determine  that  the 
_  •  •  _  was  a  P 
and  the  — 
a  Q.  For  some  rea- 
son, F  and  L  are 

regularly  confused  by  those  who  are  learning 
the  code.  Take  these  two  aside  and  have  it  out 
with  them:  they  will  never  bother  you  again. 

We  shall  suppose  that  you  know,  now,  what 
the  code  sound  for  each  letter  is — when  you 
stop  to  think.  (Call  them  "dits"  and  "dahs," 
not  dots  and  dashes;  it  helpsconsiderably  to  give 
your  ear  the  distinction  between  the  short  and 
long  code  units).  If  you  can  get  someone  to 
send  to  you  with  a  buzzer  outfit,  while  you 
sweat  away  with  paper  and  pencil,  you  should 
make  very  rapid  progress.  Be  sure  to  make 
him  send  always  a  little  faster  than  you  can  take. 
■  If  he  sends  too  slowly,  your  attention  will 
wander;  if  too  fast,  you  will  not  copy  enough 
to  keep  yourself  encouraged.  At  first,  it  is 
advisable  to  take  chiefly  five-letter  cipher 
words — xebjr,  otnla,  etc. — or  else  ordinary 
words  sent  backward.  The  reason  for  this 
is  that  if  you  think  you  know  what  is  coming, 
you  will  "anticipate" — either  writing  down 
letters  before  they  are  sent  (and  one  is  often 
fooled  doing  this)  or  by  "getting  set"  in  your 
mind  for  a  certain  letter,  thus  making  it  harder 
for  yourself  to  receive  correctly  a  different  one. 


THIS  OMNIGRAPH  WILL  RUN  OFF   1 200  WORDS  ON  ONE  WINDING 
C  regulates  the  speed— from  5  to  50  words  a  minute;  I  is  a  thumbscrew  for  changing  the 
dials;  K,  K,  are  message  changers,  which  may  be  operated  while  the  machine  is  sending 


Perhaps  it  is  impossible  or  difficult  for  you, 
in  this  period  of  your  code  development  be- 
tween the  alphabet  and  the  copying-slow-press 
stages,  to  get  someone  to  send  to  you.  In  this 
case,  you  can  have  recourse  to  either  the 
omnigraph  or  the  phonograph.  The  omni- 
graph  is  an  instrument  actuated  by  a  coiled 
steel  spring,  which,  when  connected  in  circuit 
with  an  ordinary  buzzer  and  dry  cell,  makes 
and  breaks  contacts  according  to  the  raised 
dots  and  dashes  on  its  one  or  more  revolving 
discs.  You  may  think  that  after  a  while 
you  would  know  the  omnigraph's  repertoire 
by  heart — at  least,  the  words  that  "make 
sense" — but  it  is  safe  to  say  that  by  the 
time  you  know  the  jumbled  code  letter  groups 
by  heart,  you  will  be  ready  to  copy  some 
of  the  real  thing,  anyway.  Plenty  of  it 
is  always  waiting  for  you  in  the  ether,  ready  to 
have  you  interpret  it  when  you  have  the  means. 
A  set  of  six  Victor  records  (12  lessons)  can 
be  bought,  if  desired,  which  will  send  all  kinds 
of  code  to  you,  at  every  speed  and  under 
various  conditions  (the  more  advanced  records, 
for  instance,  including  many  realistic  bursts 


A  CONVENIENT  WAY  TO  MOUNT  YOUR  BUZZER  PRACTICE  SET 


1 18 


Radio  Broadcast 


THE   PROPER  WAY  TO  HOLD  THE  KEY 


of  static  and  one  or  more  "other  stations,"  to 
give  you  practice  in  copying  through  interfer- 
ence). 

A  SIMPLE   PRACTICE  SET 

A CONVENIENT  way  of  mounting  the 
three  units  needed  for  a  practice  buzzer 
outfit  is  shown  at  the  bottom  of  page  117. 
The  dry-cell  will  cost  you  about  45  cents, 
the  buzzer  about  35  cents,  and  the  key 
anywhere  from  O  to  several  dollars.  It  will 
be  O — and  just  as  satisfactory  when  you  are 
learning  the  code — if  you  use  simply  a  strip 
of  springy  metal,  with  a  hole  in  one  end,  which 
makes  contact  with  a  screw  head  at  the  other. 
A  Meccano  toy  building  strip  is  just  the  thing. 
High-frequency  buzzers,  giving  a  two-dollar 
mosquito-like  note,  may  be  used  if  desired, 
although  the  35-cent  bark  of  the  ordinary  house 
buzzer  is  music  enough  to  the  ears  of  most 
beginners. 

A  word  about  sending — but  I  might  as  well 
say  "  a  word  "  about  how  to  drive  a  golf  ball  two 


hundred  yards.  Different 
operators  have  different 
styles,  and  all  of  them  re- 
quire a  certain  amount  of 
practice  before  being  able 
to  send  smoothly.  Some 
operators  do  it  all  with  the 
wrist,  with  such  a  flexi- 
bility that  the  hand  "posts 
in  the  saddle"  like  a  rider 
at  a  trot.  Others  "fists," 
no  less  skilful,  roll  from 
side  to  side  when  they  get 
warmed  up,  like  a  ship  at 
sea.  But  no  good  operator 
lifts  his  hand  off  the  key 
while  sending,  or  pecks 
at  the  key  like  a  chicken 
after  corn.  The  most 
generally  accepted  method 
of  holding  the  key  is  indicated  in  the  ac- 
companying photograph.  Thumb  on  the  side 
of  the  key-knob  for  steadying,  first  finger 
on  top  for  applying  the  downward  pres- 
sure, and  middle  finger  below,  to  steady 
the  hand  and  to  give  the  necessary  upward 
pressure  when  the  key  contacts  stick  (as  fre- 
quently happens  when  a  heavy  current  is  used). 
The  more  you  use  your  wrist  in  sending,  rather 
than  your  fingers,  the  less  cramped  your  hand 
will  be.  In  this  respect,  what  it  true  of 
penmanship  is  true  of  telegraphy. 

You  know  the  kind  of  fellow  who  always 
drives  a  car  as  fast  as  he  can,  faster  than 
safety  permits;  and  the  kind  who  always  talks 
loud  and  long,  no  matter  what  other  people 
may  have  to  say.  These  types  are  found, 
alas!  in  the  radio  game  as  well  as  elsewhere. 
The  first  type  sends  out  a  jumble  of  rushed 
and  mutilated  signals;  and  the  second  jams  the 
air  with  endless  calls,  tests,  or  "  bull. "  Having 
mentioned  these  horrible  examples,  need  more 
be  said? 


What  Would  You  Like  to  Have  in  Radio  Broadcast  ? 

The  editor  would  be  pleased  to  hear  from  readers  of  the  magazine  on  the  following  {or  other)  topics: 

1.  The  kind  of  article,  or  diagram,  or  explanation,  or  improvement  you  would  like  to  see  in 
Radio  Broadcast. 

2.  What  has  interested  you  most,  and  what  least,  in  the  numbers  you  have  read  so  far. 


Is  Short-wave  Relaying  a  Step  Toward 
National  Broadcasting  Stations? 

Listeners-in  in  Cleveland,  Ohio,  Now  Hear  Pittsburgh  as  Distinctly 
as  They  Hear  Local  Stations,  by  a  New  Method  of  Broadcasting 

By  W.  W.  RODGERS 

Westinghouse  Electric  &  Mfg.  Co. 

Re-broadcasting  is  a  system  of  transmitting  on  a  certain  wavelength,  picking  up  the  signals  at  a  remote 
point,  and  using  the  received  energy — amplified  locally — to  actuate  other  broadcasting  transmitters  on  one 
or  more  different  wavelengths. 

The  possibilities  of  re-broadcasting  are  indeed  staggering.  A  central  station,  located  in  Washington, 
for  example,  could  carry  the  voice  of  the  President  to  listeners  in  every  section  of  our  country  if  re-broad- 
casting, as  described  in  this  article,  were  properly  fostered.  That  is  a  large  order,  but  we  shall  undoubtedly 
see  its  realization  by  this  or  some  similar  system  before  long.  This  article  by  Mr.  Rodgers  is  the  first  to  appear 
on  this  very  interesting  development. — The  Editor. 


PERHAPS  there  is  no  phase  of  broadcasting 
that  appeals  to  all  of  us  more  than  the  estab- 
lishment of  national  broadcasting  stations — 
just  a  few  of  them  distributed  carefully  at 
selected  centres  throughout  the  country  so 
that  they  serve  all  sections  in  a  satisfactory  manner. 
One  large  station,  for  instance,  might  serve  the  public 
within  a  radius  of  500  miles,  and  enough  of  these 
stations  could  be  established,  under  government  regula- 
tion, so  that  no  one  within  these  circles  would  lack 
entertainment  —  or  get  too  much  of  it  on  interfering 
waves. 

The  present  trend  in  radio  seems  to  indicate  that 
the  national  broadcasting  station  will  help  to  solve  some 
of  the  most  important  broadcasting  problems. 

Already,  the  Westinghouse  Electric  &  Manufacturing 
Company  has  successfully  relayed  concerts  on  80  to 
1 00-meter  wavelengths  with  results  that  warrant  further 
research  along  this  line.    Programs  from  KDKA,  the 
company's  broadcasting  station  at  East  Pittsburgh, 
have  been  relayed  from  its  experimental  station,  KDPM, 
in  Cleveland,  Ohio  and  from  WBZ,  in  Springfield, 
Mass.    In  both  these  cities, 
K  D  KA's  concerts  have  been 
received  with  great  clarity, 
even  though  Cleveland  is 
one  of  the  so-called  "dead" 
spots  of  the  country. 

Short-wave  relaying  and 
the  establishment  of  na- 
tional broadcasting  stations 
are,  therefore,  pertinent  sub- 
jects in  which  every  radio 
fan,  engineer,  and  manu- 
facturer should  be  vitally 


THE  SHORT  ANTENNA  USED  FOR   IOO-METER  TRANSMISSION 
Erected  at  KDKA,  East  Pittsburgh,  Pa. 


120 


Radio  Broadcast 


THE  lOO-METER  VOICE  AMPLIFIER  AT  KDKA 

interested.  Mr.  H.  P.  Davis,  vice-president 
of  the  Westinghouse  Company,  is  said  to  be 
the  first  to  suggest  national  broadcasting.  His 
plan  involves:  "The  establishment  of  radio 
broadcasting  on  the  same  basis  as  other  public 
utilities,  with  an  Interstate  Radio  Commission 
and,  therefore,  a  Federal  Commission  created 
by  presidential  appointment.  This  commis- 
sion would  be  vested  with  full  power  and  auth- 
ority to  make  regulations  and  enforce  them  to 
the  full  extent.  A  transmitting  license  would 
then  take  on  the  nature  of  a  franchise  because 
of  the  large  expense  necessary  in  establishing  a 
high-class  station.  There  would  be  established 
two  classes  of  broadcasting  stations.  First, 
the  stations  national  in  scope,  and  second,  local 
stations  serving  particular  districts.  The  local 
stations  could  be  made  non-interfering  by  the 
allocation  of  different  wave  bands.  " 

This  plan,  of  course,  must  be  worked  out  in 
all  its  various  phases,  a  task  requiring  great 
attention  to  details  and  the  solving  of  many 
engineering  problems  incidental  to  its  per- 
fection. One  difficulty,  which  has  possibly 
already  occurred  to  you  is  the  fact  that  the  small 
receiving  set,  especially  if  it  is  of  the  crystal 
detector  type,  would  be  unable  to  pick  out  the 
long-distance  stations,  and  would  therefore  be 


quite  out  of  the  radio, 
world.  Here  is  where 
short-wave  relaying  sup- 
plies the  missing  link  be- 
tween the  large  national 
station  and  the  small  re- 
ceiver. 

Just  what  is  the  plan  of 
short-wave  relaying? 
Briefly,  it  is  the  broad- 
casting of  programs  on  a 
wavelength  below  100 
meters,  to  be  picked  up 
at  one  or  more  distant  stations  and  relayed 
on  a  higher  wavelength  to  serve  the  receiving- 
set  owners  in  the  districts  surrounding  the 
relaying  stations. 

The  Westinghouse  Company  has  been  carry- 
ing on  experiments  with  this  method  of  broad- 
casting for  the  past  year  and  has,  in  that  time, 
been  able  to  gather  a  great  deal  of  useful  data 
from  these  experiments.  Frank  Conrad,  as- 
sistant chief  engineer  of  the  company,  and 
welPknown  in  the  radio  world  because  of  his 
station,  8XK,  is  believed  to  be  the  man  who 
first  experimented  with  broadcasting  on  these 
very  short  wavelengths.  Before  Mr.  Conrad 
got  into  the  work,  radio  engineers  had  proved 
by  mathematics  that  transmission  on  short 
waves  was  impracticable,  but  he  had  an  idea 
that  their  calculations  might  not  be  correct, 
and  decided  to  investigate  for  himself  the 
possibilities  of  broadcasting  effectively  on 
wavelengths  of  100  meters  or  lower.  First, 
he  built  a  set  to  transmit  on  100  meters  and 
found  by  tests  with  an  amateur  operator  in 
Boston  that  the  ioo-meter  wavelength  was 
more  selective  and  more  efficient  than  even 
360  meters.  Mr.  Conrad  next  arranged  for  a 
private  telephone  connection  between  Station 
KDKA  and  his  home,  about  four  miles  distant, 
and  by  a  special  circuit  arranged  to  receive 
programs  from  the  studio  circuit  over  his 
telephone  line.  He  then  connected  this  tele- 
phone line  to  his  100-meter  transmitting  set 
and  sent  out  KDKA's  programs  simultane- 
ously with  the  broadcasting  on  360  meters. 

In  Boston  and  other  places  it  was  reported 
that  this  transmission  was  stronger  than  the 
signals  received  directly  from  KDKA  on  360 
meters!  This  was  true,  even  though  his 
station  was  much  less  powerful  than  the  one  at 
East  Pittsburgh. 

With  these  facts  in  mind,  the  Westinghouse 
radio  engineering  department  decided  to  try 


Is  Short-wave  Relaying  a  Step  Toward  National  Broadcasting  Stations?  121 


THE  LOO-P—AN-D  RECEIVING  SET  AT  THE  CLEVELAND  STATION,  KDPM 
§5  a  -This  is  wh  ere  the  broadcasts,  sent  from  KDKA  on  100  meters,  were  received 


experiments  with  Cleveland,  where  the  broad- 
casts from  KDKA  on  360  meters,  had  never 
been  satisfactorily  received.  To  that  end  a 
relaying  station  was  established  in  the  Cleve- 
land Foundry,  located  on  the  Lake  end  of 
West  58th  St.,  and  the  short-wave  relaying  tried 
out.  _Tt  was  not  long  before  Cleveland  fans 
were  reported  receiving  signals  from  KDKA 
with  the  same  volume  as  they  were  receiving 
local  broadcasting. 

-The  same  thing  is  now  going  to  be  tried  out 
in  the  Springfield  station  as  an  adjunct  to  the 
programs  broadcasted  from  WBZ. 

The  mechanics  of  relaying  presented  a  great 
many  problems  which  had  to  be  worked  out 
gradually  as  they  presented  themselves. 

%  In  order  to  carry  on  This  short-wave  relaying, 
it  was  thought  best  to  employ  two  transmitters 
controlled  from  the  same  microphone,  one 
transmitter  operating  on  360  meters,  the  other 
on  100  meters.  This  was  done  and  now  there 
are  also  two  antennas — KDKA's  long  antenna 


which  is  105  feet  high  and  200  feet  long,  used 
for  broadcasting  on  360  meters,  and  the  short- 
wave antenna  which  is  35  feet  high  and  40 
feet  long,  used,  of  course,  for  sending  the  100- 
meter  signals.  . 

In  Cleveland,  the  100-meter  signals  are  re- 
ceived on  a  loop  eight  feet  square,  for  the  rea- 
son that  the  ordinary  inverted  L  antenna  might 
throw  the  receiving  station  out  of  tune  if  it 
swung  in  the  wind.  This  antenna  is  located 
inside  the  building  and  is  connected  to  a  single- 
circuit  detector  unit,  with  two  stages  of  ampli- 
fication. The  output  of  the  receiver  is  de- 
livered directly  to  a  250-watt  transmitting  set, 
containing  one  oscillating  and  one  modulating 
tube.  The  transmitting  antenna  is  duplicate  of 
the  one  at  East  Pittsburgh  used  for  sending  on 
360  meters  (105  feet  high  and  200  feet  long.) 

Naturally  there  are  difficulties  encountered 
in  relaying  these  short-wave  signals.  For 
instance,  the  small  size  inductances  and  capaci- 
ties   are   difficult    to    construct.    A  slight 


122 


Radio  Broadcast 


change,  like  the  swinging  of  the  antenna,  will 
change  the  wavelength  and  throw  the  receiver 
out  of  tune.  On  the  other  hand,  the  efficiency 
on  100  meters  or  lower- is  comparatively  high,  on 
account  of  the  lower  electric  losses  which  permit 
greater  radiation  from  a  given  antenna  at  the 
same  power  input  than  is  possible  when  sending 
on  360  meters. 

Perhaps  the  principal  reason  why  short- 
wave broadcasting  will  prove  important  in 
future  radio  telephone  stations  is  that  it  will 
open  up  a  great  range  of  wavelength  bands. 
This  is,  of  course,  irrespective  of  the  possibili- 
ties of  national  broadcasting.  For  instance, 
there  are  only  25  wavelength  bands,  each 
10,000  cycles  wide,  between  300  and  400  meters, 
whereas  there  are  300  such  bands  between  the 
wavelengths  of  50  to  100  meters.  This  fact  may 
lead  to  the  solution  of  the  interference  problem 
that  confronts  broadcasting  as  we  know  it  to-day. 

There  are  other  things  to  be  taken  into  con- 
sideration which  show  that  the  lower  wave- 
lengths have  some  very  desirable  characteris- 
tics. It  has  been  observed  that  static  is  less 
noticeable  than  on  360  meters.  This  was 
found  to  be  true  when  the  same  concert  was 
heard  simultaneously  on  360  meters  and  100 
meters.  A  dash  of  static  that  would  complete- 
ly drown  out  the  360-meters  broadcasting  would 
scarcely  be  noticeable  on  the  100-meter  wave- 
length. 


Another  advantage,  indicated  by  these  tests 
is  that  daylight  does  not  reduce  the  range 
of  the  short-wave  broadcasting  as  it  does  when 
the  360-meter  wavelength  is  used.  At  direct 
variance  with  the  system  in  use  to-day,  first 
tests  have  shown  that  daylight  transmission  is 
materially  better  than  night  transmission  at  a 
wavelength  of  80  meters.  It  is  believed, 
though  still  unproven,  that  there  will  not  be  the 
falling  off  in  distance  in  the  summer  time  which 
is  one  of  the  handicaps  of  broadcasting  at 
present. 

There  are,  to  be  sure,  some  drawbacks  to 
broadcasting  on  extremely  short  waves.  The 
most  serious  is  that  the  receiver  gets  out  of 
tune  very  easily.  This  is  frequently  due  to  the 
swinging  of  the  antenna,  but  this  sort  of  trouble 
could  be  easily  reduced  by  using  some  sort  of 
fixed  antenna,  or  a  loop  such  as  is  used  at 
KDPM. 

Mr.  Davis  has  already  suggested  the  re- 
laying, by  stations  of  limited  power,  of  concerts 
broadcasted  from  a  powerful  central  station, 
so  that  the  whole  country  might  listen  to  the 
same  concert.  That  such  a  plan  is  feasible 
for  a  comparatively  small  area,  the  Westing- 
house  Company's  experiments  have  proved; 
and  since  the  theory  itself  is  known  to  be 
sound,  it  seems  that  the  development  of  a 
national  broadcasting  system  can  be  a  matter 
of  only  a  few  years. 


ANOTHER  "CAVE  MAN" 

Mr.  N.  M.  McCoy,  of  Monmouth, 
Illinois,  sends  us  this  picture,  and 
says:  "Talk  about  cave-man  stuff 
—how  does  this  set  look  to  you? 
Cigar  boxes  nailed  on  a  board,  for 
a  panel.  Have  listened-in  on  most 
every  station  from  Minneapolis  to 
Atlanta  and  from  Newark  to 
Dallas!  I  enjoyed  Mr.  Tannehill's 
article  ■  [  Radio  Broadcast  for 
February,  1923]  very  much  and 
have  had  all  his  experiences  and 
then  some.  He  says:  'buy  your 
parts,  tie  them  together,  part  your 
hair  in  the  middle,  and  go  after 
Havana.'  I  can't  part  my  hair  in 
the  middle;  but  I  have  seen  the 
time  when  if  the  second  hand  on  my 
watch  had  stopped  I  know  I  would 
have  made  the  station." 


The  Best  Battery  Connections  for  the 

Circuit  You  Use 

Perhaps  Your  Tubes  Are  Not  Working  at  Their  Best.  Different  Arrange- 
ments of  A  and  B  Batteries  are  Necessary  for  Best  Operation  of  a  Tube  When 
Used  as  Detector  and  When  Used  as  Amplifier.    Check  Up  Your  Own  Circuit 

By  EDWARD  LINDLEY  BOWLES 

Instructor  in  Electrical  Communication,  Massachusetts  Institution  of  Technology 


A  T  THE  present  time,  there  seems  to 
/%      be  much  confusion  in  the  arrange- 

/  \  ment  of  A  batteries  in  vacuum-tube 
/  %  circuits.  One  detector  circuit  may 
be  shown  with  the  grid  connected 
to  the  positive  side  of  the  A  battery,  whereas  an- 
other detector  circuit 
of  the  same  nature 
may  be  shown  with  the 
grid  connected  to  the 
negative  side.  The 
same  is  true  in  the  case 
of  audio-frequency 
amplifiers.  And  the 
negative  terminal  of 
the  B  battery  is  usu- 
ally connected  to  the 
negative  side  of  the  A 
battery  for  no  appar- 
ent reason  other  than 
that  it  is  the  custom. 

In  many  descrip- 
tions of  circuits,  the 
reader  is  confronted 
with  the  expression 
"at  zero  grid  poten- 
tial," or  "with  a  grid 

potential  of  minus  i  volt" — another  means  of 
expressing  the  same  thing — or  "a  negative  bias 
of  i  volt."  One  may  well  question  the  exact 
meaning  of  these  terms,  if  the  grid  can  be 
arbitrarily  connected  to  the  positive  or  negative 
side  of  the  A  battery. 

In  order  that  the  characteristics  of  a  vacuum 
tube  may  be  clearly  defined,  it  is  customary  to 
state  them  in  terms  of  connections  made  to  the 
negative  side  of  the  A  battery.  In  this  way, 
you  can  clearly  understand  that  if  the  grid  of  a 
vacuum  tube  is  said  to  have  a  negative  potential 
of  i  volt,  it  is  i  volt  more  negative  than  the 
side  of  the  filament  connected  directly  to  the 
negative  terminal  of  the  A  battery.    But  here 


Do  You  Know: 

Why  a  rheostat  is  placed  in  the  positive  fila- 
ment lead  in  some  circuits  and  in  the  negative 
lead  in  others? 

Why  the  negative  terminal  of  the  B  battery 
is  sometimes  connected  to  the  positive  and 
sometimes  to  the  negative  terminal  of  the  A 
battery? 

What  determines  your  grid  potential,  and 
what  effect  has  it  on  your  circuit? 

Why  a  potentiometer  is  used  with  a  "soft" 
detector  tube  such  as  the  UV-200,  and  not  with 
theWD-n? 

How  to  make  the  proper  connections  for 
various  tubes  used  as  detectors  and  amplifiers? 

If  not,  this  article  will  be  of  interest  and 
value  to  you. 

Keep  it  handy. — The  Editor. 


again  a  question  may  arise,  for  circuit  drawings 
are  shown  with  the  filament  rheostat  some- 
times in  the  positive,  sometimes  in  the  negative, 
side  of  the  filament  circuit.  If  the  filament 
rheostat  is  in  the  negative  filament  lead,  then, 
even  though  the  grid  is  connected  to  the  nega- 
tive side  of  the  fila- 
ment battery,  it  is  not 
at  the  same  electrical 
potential  as  the  nega- 
tive side  of  the  fila- 
ment. In  actual  prac- 
tice, there  are  some- 
times certain  advan- 
tages in  placing  the 
filament  rheostat  in 
one  particular  side  of 
the  filament  circuit. 
Again,  there  may  be 
particular  advantage 
in  connecting  the  grid 
to  a  particular  side  of 
the  filament  battery. 
The  reasons  for  special 
arrangements  of  con- 
nections to  the  A  and 
B  batteries  can  be 
made  clear  by  a  few  simple  diagrams. 

In  Fig.  1,  a  vacuum  tube  is  shown  with  all 
batteries  connected.  The  voltmeter,  in  the 
grid  circuit  (Fig.  1)  indicates  the  potential  of 
the  grid  with  respect  to  the  negative  end  of  the 
filament.  When  the  grid  is  connected  directly 
to  the  negative  end  of  the  filament,  that  is, 
when  the  C  battery  is  removed  from  the  grid 
circuit  and  the  point  M  is  directly  connected 
to  the  point  N,  the  grid  is  said  to  be  at  zero 
potential.  It  must  be  remembered  that  it  is 
at  zero  potential  only  with  respect  to  the  point 
H  of  the  filament.  The  point  K  of  the  filament 
is  more  positive  than  the  point  H,  since  it  is 
closer  to  the  positive  side  of  the  A  battery. 


124 


Radio  Broadcast 


Plate 

Ammeter 


FIG.  I 


The  fundamental  vacuum-tube  circuit  from  which  plate, 
grid  and  filament  voltages  for  the  proper  operation  of 
various  types  of  tubes  may  be  ascertained 


Whenever  the  characteristic  curves  of  vacuum 
tubes  are  referred  to,  they  are  obtained  by  the 
standard  connections  shown  in  Fig.  i . 

It  does  not  follow,  from  this  discussion,  that 
the  connections  of  the  batteries  shown  in  Fig.  i 
are  best  for  practical  applications  of  thevacuum 
tube.  Where  a  hard  tube  is  used  as  a  detector 
it  is  unnecessary  to  connect  the  negative  side  of 
the  B  battery  to  the  negative  side  of  the  A 
battery.  Very  often  it  is  of  advantage  to  con- 
nect the  negative  side  of  the  B  battery  to  the 
positive  side  of  the  A  battery  so  as  to  have  the 
advantage  of  augmenting  the  B  battery  vol- 
tage by  the  A  battery  voltage.  Also,  it  is  us- 
ually more  satisfactory  to  connect  the  grid  of 
the  detector  tube  to  the  positive  side  of  the  A 
battery,  because  a  detector  tube  usually  works 
best  when  the  A  battery  tends  to  make  the  grid 
slightly  positive.  Connections  for  a  hard  de- 
tector tube,  such  as  the  UV-201-A,  the  WD-i  1, 


Grid  Leak 


Tunerj 


Gridj 


Condenser^ 

Li. 

> 

1 
1 
1 
■ 

A 

_.  i  — 

+ 

FIG.  2 

When  a  hard  tube  such  as  a  WD-11,  C-300,  C-301-A, 
UV-199,  UV-201,  or  UV-201-A,  is  used  as  a  detector, 
this  circuit  arrangement  may  be  used 


or  the  VT-2,  are  shown  in  Fig.  2.  In  this 
case,  the  grid  is  connected  to  the  positive  side 
of  the  A  battery.  The  plate,  or  B  battery, 
is  also  connected  to  the  positive  side  of  the  A 
battery,  and  the  filament  rheostat  R  is  placed 
in  the  negative  side  of  the  filament.  In  this 
way,  any  variation  in  the  filament  current  does 
not  affect  the  potential  of  the  grid  as  much  as 
if  the  filament  rheostat  were  placed  in  the  posi- 
tive filament  lead. 

Figure  3  shows  a  detector  circuit  arranged 
for  using  a  soft  detector  tube,  such  as  the  UV- 
200.  In  this  case  the  grid  is  once  more  con- 
nected to  the  positive  side  of  the  A  battery  and 
the  rheostat  is  placed  in  the  negative  filament 
lead.  Since  this  type  of  tube  is  very  sensitive 
to  a  change  in  plate  voltage,  a  potentiometer, 
P,  is  inserted  as  shown.  Under  these  condi- 
tions, if  an  18-volt  tap  is  taken  on  the  B  bat- 


fig.  3 

When  using  a  soft  detector  tube,  such  as  the  C-300, 
UV-200  or  some  of  the  old  De  Forest,  Audiotron  and  A-P 
tubes,  this  circuit  arrangement  is  better  than  the  de- 
tector circuit  shown  in  Fig.  2 

tery,  then  if  the  potentiometer  slider  is  at  the 
point  N,  the  plate  will  have  a  potential  of  24 
volts  (if  a  6-volt  A  battery  is  used).  When  the 
potentiometer  slider  is  at  the  point  M;  the  plate 
will  have  a  potential  of  about  17  volts  (owing 
to  a  drop  of  about  1  volt  in  the  filament 
rheostat).  By  this  arrangement  the  plate 
potential  can  be  adjusted  to  an  optimum  opera- 
ting value,  as  required  by  the  particular  tube 
in  the  socket. 

In  the  case  of  an  amplifier,  the  problem  is  a 
different  one.  As  long  as  the  grid  of  the  am- 
plifier tube  is  positive,  distortion  will  take  place. 
In  fact,  in  many  cases  it  is  necessary  to  give  the 
grid  a  decided  negative  potential,  with  respect 


The  Best  Battery  Connections  for  the  Circuit  You  Use 


125 


to  the  most  negative  end  of  the  filament,  in 
order  that  efficient  and  relatively  distortionless 
amplification  may  be  obtained.  It  is  also  of 
advantage  to  operate  an  amplifier  tube  at  a 
higher  potential  than  a  detector  tube.  There- 
fore, the  negative  end  of  the  plate  battery 
might  just  as  well  be  connected  to  the  positive 
side  of  the  A  battery  in  order  that  the  plate 
voltage  may  be  augmented  by  that  of  the  fila- 
ment battery. 

Figure  4  illustrates  the  connection  of  the  A 
and  B  batteries  in  the  case  of  an  amplifier  tube. 
The  grid  connects  to  the  negative  side  of  the  A 
battery.  The  filament  rheostat  R  is  also 
placed  in  the  negative  side  of  the  filament 
battery.  The  negative  side  of  the  B  battery  is 
connected  to  the  positive  side  of  the  A  bat- 
tery. The  insertion  of  the  filament  rheostat 
in  the  negative  side  of  the  filament  has 
the  advantage  of  giving  the  grid  a  slight 
negative  potential.  In  fact,  if  a  6-volt  A 
battery  is  used,  where  the  actual  filament  volt- 
age required  is  only  5,  there  will  be  a  i-volt 
drop  m  -the  filament  rheostat.'  This  means  that 
the  point  D  is  one  volt  more  positive  than  the 
point  E,  which  is  the  most  negative  point  on 
the  circuit.  An  audio-frequency  amplifier  will 
operate  better  with  the  filament  rheostat  in  this 
position,  since  the  grid  will  be  automatically 
given  a  slight  negative  bias.  The  disadvantage 
which  attends  this  arrangement  lies  in  thefact 
that,  as  the  A  battery  discharges,  less  and  less 
of  the  rheostat  resistance  is  required.  When 
the  A  battery  has  reached  a  potential,  let  us 
say,  of  that  actually  required  by  the  tube  itself, 
then  all  the  resistance  will  have  been  cut  out 
of  the  rheostat  and  the  grid  will  have  no  nega- 
tive potential  or  "  bias." 

Many  commercial  amplifiers,  either  radio- 
frequency  or  audio-frequency,  cannot  incor- 
porate this  arrangement  having  a  filament 
resistance  inserted  in  the  negative  side  of  the 
filament  lead,  because  there  are  certain  patents, 
held  by  one  of  the  large  corporations,  which 
preclude  the  use  of  it. 

Another  arrangement  for  an  amplifier  circuit 
is  shown  in  Figure  5.  In  this  case,  a  C  or  grid 
biasing  battery  is  used,  so  that  the  grid  may 
be  given  any  negative  potential  desired  simply 
by  inserting  the  proper  number  of  cells  in  the  C 
battery.  Flashlight  cells  are  very  convenient 
for  this  purpose,  because  of  their  small  size. 
The  approximate  electromotive  force  of  such 
cell  is  1 1  volts.  Cells  used  in  the  C  battery 
should  be  placed  as  close  to  the  A  battery  as 


fig.  4 

In  amplifier  circuits,  hard  tubes  should  always  be  used 
and  this  circuit  arrangement  may  be  used  to  advantage. 
A  negative  bias,  equal  to  the  voltage  drop  across  the  fila- 
ment rheostat,  is  automatically  imposed  on  the  grid.  If 
the  A  battery  is  kept  well  charged,  the  use  of  a  C  battery 
is  usually  unnecessary  where  this  circuit  is  employed 

possible,  and  should  not  be  placed  near  the 
grid,  as  shown  by  'the  point  H. 

Various  tubes  require  various  negative  biases 
when  used-  as  amplifiers.  The  new  201-A 
tube  requires  from  -0.5  to  -5  volts,  depending 
upon  the  plate  voltage.  The  Western  Electric 
VT-i's  require  from  o  to  -3.  The  Western 
Electric  216  -A  tube,  which  is  used  in  the 
W.E.  power  amplifier,  requires  a  bias  of  ap- 
proximately -6  volts,  and  the  WD-i  1  re- 
quires a  bias  of  from  o  to  -4. 

Figure  6  shows  the  use  of  a  stabilizer  or 
potentiometer.  By  the  use  of  this  device,  the 
grid  bias  may  be  varied  when  the  tube  is  under 


+  -  -»- 


F1G.  5 

The  value  of  the  negative  potential  applied  to  the  grid 
may  be  varied  by  manipulation  of  the  number  of  cells 
in  the  C  battery  in  this  circuit.  The  connection  between 
the  A  and  C  batteries  should  be  as  short  as  possible. 
The  rheostat,  in  this  instance,  is  in  the  positive  lead  of 
the  A  battery 


126 


Radio  Broadcast 


In  put  C 


■  |  ■  |  ■  1 1 

Amplifier 
Output 


The  best  arrangement  for  amplifier  tubes  is  shown  here. 
By  means  of  the  400-ohm  potentiometer  it  is  possible  to 
procure  the  best  value  of  grid  voltage  for  the  operation 
of  the  particular  tube  you  are  using 

operation,  so  that  the  optimum  point  of  opera- 
tion may  be  readily  secured.  A  potentiometer 
of  comparatively  high  resistance  must  be  used 
for  this  purpose,  as  otherwise  the  loss,  due  to 
the  steady  current  sent  through  it  by  the  A  and 
C  batteries,  which  are  in  series,  may  become 
expensive  and  objectionable. 

The  A  battery  may  consist  of  dry  cells,  in 
the  case  where  WD-i  i  or  UV-20I-A  tubes  are 
used,  but  it  will  probably  be  a  storage  battery, 
since  several  or  either  of  these  tubes  may  be 
operated  in  parallel.  The  C  battery  can  be 
made  up  best  of  ordinary  dry  cells,  since  flash- 
light batteries  will  wear  out  very  much  sooner 
in  circuits  where  a  potentiometer  is  used,  as  in 
figure  6.  For  example,  if  the  resistance  of  the 
potentiometer  is  400  ohms, 
then  for  a  6-volt  A  battery 
and  a  4-volt  C  battery, 
there  will  be25  milliamperes 
flowing  during  the  period 
when  the  tube  is  in  opera- 
tion. 

Figure  7  illustrates  the 
use  of  a  soft  detector  tube 
in  conjunction  with  two 
stages  of  audio  -  frequency 
amplification,  in  which  UV- 
20 1 -A  tubes  are  used.  The 
potentiometer  P  furnishes 
the  necessary  fine  variation 
in  plate  voltage  for  the 
proper  operation  of  the  soft 
detector  tube.  The  plate 
lead  of  the  detector  tube  is 
connected  to  the  primary 
of  the  first  audio-frequency 


transformer,  and  then  to  the  22^-volt  tap  on 
the  B  battery.  The  grids  of  the  two  amplify- 
ing tubes  are  given  a  negative  bias  of  from  -1 
to  -4.5  volts  by  means  of  the  biasing  battery 
shown.  This  particular  battery  may  consist 
best  of  a  flashlight  type,  for,  as  it  carries  almost 
no  current,  its  life  will  be  practically  its  "shelf 
life."  The  jacks  enable  the  operator  to 
utilize  the  detector  tube  alone,  or  the  detector 
tube  in  conjunction  with  one  or  both  of  the 
stages  of  amplification.  The  plate  potential 
of  the  two  amplifier  tubes  varies  from  60  to  80 
volts.  A  potential  of  60  volts  will  probably 
be  ample,  unless  the  receivers  are  replaced  by 
a  loud-speaking  device.  Beyond  a  certain 
point,  there  is  little  advantage  in  increasing 
the  plate  voltage.  The  biasing  battery  has  a 
tendency  to  increase  the  intensity  of  the  signals 
over  certain  ranges  of  frequency,  but  with 
ordinary  amplifying  transformers,  the  im- 
provement, due  to  the  insertion  of  the  C  bat- 
tery, may  produce  comparative  distortion,  be- 
cause it  will  tend  to  make  the  amplifier  operate 
more  powerfully  for  certain  frequencies,  and 
no  better  for  others. 

Figure  8  shows  a  similar  circuit,  to  be  used 
with  three  WD-i  1  tubes,  the  first  tube  acting 
as  a  detector.  In  this  case,  there  is  no  poten- 
tiometer in  the  detector-tube  circuit,  since  the 
detector-tube  plate  voltage  is  not  critical.  The 
grid  bias  is  furnished  by  the  necessary  number 
of  flashlight  cells,  inserted  as  shown  by  C  in  the 
figure.  WD-i  1  tubes  will  work  very  well 
without  any  biasing  battery,  but  under  these 


C  -  300 
UV-200 


C  301-fl 
UV-20  l-A 


C-301-n 
UV-2.01  A 


FIG.  7 

This  is  a  detector  and  two-stage  audio  amplifier  circuit  which  may  be  made  of 
standard  parts  and  applied  to  any  receiver.    The  detector  tube  should  be  soft, 
such  as  the  C-300,  UV-200,  Moorehead,  Audiotron,  or  De  Forest  detector  type. 
Any  hard  tubes  may  be  used  in  the  amplifier  circuit 


The  Best  Battery  Connections  for  the  Circuit  You  Use 


127 


conditions  it  would  be  bet-  WD- 
ter  to  put  the  filament 
rheostats  in  the  negative 
filament  leads  of  the  two 
amplifying  tubes  shown.  I  n 
the  figure,  the  rheostats  are 
placed  in  the  positive  fila- 
ment leads  of  the  two  tubes, 
owing  to  the  insertion  of 
the  "  C,"  or  biasing  battery. 

Where  the  battery  ar- 
rangement shown  in  figure  7 
.is  used  in  a  radio-frequency 
amplifier  circuit,  the  circuit 
will  probably  be  subject  to 
oscillation  the  moment  the 
grid  becomes  the  least  bit 
negative,  so  that  the  C  bat- 
tery shown  is  hardly  nec- 
essary. Logically,  it  would  be  ideal  to  oper- 
ate the  tube  with  a  negative  grid  potential, 
but  in  the  case  of  most  radio-frequency 
amplifiers,  the  grid  must  be  made  slightly 
positive  in  order  to  introduce  a  loss,  which 
will  keep  the  circuit  from  oscillating.  Any 
mechanical  or  electrical  system  will  vibrate  if 
it  is  once  excited,  as  long  as  the  resistance,  or 
the  friction  in  the  circuit,  is  below  a  certain 
value.  However,  if  the  resistance  is  increased, 
then  the  system  will  cease  to  oscillate.  This  is 
evident,  for  example,  in  the  case  of  the  pendu- 
lum of  a  clock.  If  the  pendulum  of  a  clock  is 
once  pulled  aside,  it  will  oscillate  for  some  time, 
even  though  the  clock  may  not  be  wound.  If 
the  clock  is  wound,  the  spring  furnishes  energy 
to  the  pendulum  as  fast  as  it  is  lost  to  the  fric- 
tion, so  that  the  pendulum  continues  to  oscil- 
late. However,  if  the  pendulum  were  im- 
mersed in  some  very  viscous  liquid,  then,  even 


fig.  8 

Three  WD-11  tubes  are  used  in  this  circuit. 

it  is  better  to  place  the  filament  rheostats  for  the  two  amplifier  tubes  in  the  negative 
lead  of  the  A  battery,  instead  of  the  positive  as  shown  here 


If  the  C  battery  is  not  employed, 


though  it  were  given  an  impulse,  it  would  not 
oscillate  at  all. 

A  C  battery  in  the  ordinary  radio-frequency 
circuit  is  of  no  use,  for  the  losses  just  mentioned 
must  be  introduced  in  order  to  keep  the  circuit 
from  sliding.  In  the  case  of  audio-frequency 
amplification,  the  results  will  be  very  disap- 
pointing if  the  grid  is  connected  to  the  positive 
side  of  the  A  battery,  but  very  satisfactory  if 
the  grid  is  given  a  negative  bias  of  the  proper 
amount. 

The  various  arrangements  shown  illustrate 
the  possible  interconnections  of  the  A  and  B 
batteries,  and  from  an  inspection  of  them,  it 
should  be  clear  that  most  circuits,  as  popularly 
shown,  have  been  arranged  subject  to  state- 
ments made  in  advanced  treatments  of  vacuum 
tubes,  in  which  the  standard  circuit  shown  in 
Fig.  1  is  used  as  a  standard  basis  for  comparison 
only. 


A  Man  Who  Built  A  Set  He  Has 

Never  Seen 


By  ALFRED  M.  CADDELL 


NE  sunshiny  day  in  September, 
1899,  a  police  officer  patroling 
the  streets  in  the  Harlem  district 
of  New  York  heard  the  cry 
"Help!  Help!"  coming  from  a 
tenement  house.  Rushing  into  the  darkened 
hallway,  he  hurried  up  the  stairs.  Suddenly 
a  shot  rang  out,  fol- 
lowed by  another  shot 
— and  then  the  whole 
world  became  dark  to 
him. 

The  officer  was 
taken  to  the  Harlem 
hospital.  The  best 
doctors  in  the  city 
were  rushed  to  his 
side.  One  of  the  bul- 
lets had  entered  his 
chest;  but  the  other 
had  penetrated  his 
eyes  and  wrought  such 
havoc  that  both  of 
them  had  to  be  re- 
moved, depriving  him 
of  his  sight  forever. 

That  was  almost  a 
quarter  century  ago 
and  during  all  the  in- 
tervening years  the 
likeness  of  no  new  ob- 
ject has  come  into  this 

ex-policeman's  life.  But  since  that  day  he  has 
done  some  remarkable  things,  not  the  least  of 
which  has  been  to  construct  a  radio  receiving 
set  totally  unassisted  by  any  one  except  his 
twelve-year-old  boy  who  read  aloud  various 
radio  items  and  plans  culled  from  newspapers 
and  magazines! 

Patrick  O'Keefe  was  born  in  the  Harlem  dis- 
trict forty-eight  years  ago.  He  received  his 
education  in  the  public  schools — that  is,  up  to 
the  age  of  eleven — and  then  started  out  to  make 
his  own  living.  Telegraphy  sent  out  a  call  to 
him,  and  soon  he  became  very  proficient  in  the 
Morse  code.    He  acquired  a  typewriter  and 


Radio  can  and  should  be  a  permanent  and 
increasing  blessing  to  those  who  cannot  see. 
It  is  the  one  best  way  in  which  the  blind  can 
lose  the  sense  of  remoteness  from  the  lives  of 
other  people,  and  can  enjoy  the  manifold  ac- 
tivities which  engage  a  busy  world. 

No  doubt  the  manual  skill  and  the  power  of 
visualization  possessed  by  Mr.  O'Keefe  are 
qualities  not  found  in  all  blind  people.  But 
whether  they  make  their  own  sets  or  not,  they 
should  be  introduced  to  the  advantages  that 
radio  can  bring  them.  As  Mr.  O'Keefe  says, 
"Let  the  blind  be  thankful  that  radio  is  at 
hand — and  also,  let  them  use  it." 

Those  who  can  afford  their  own  apparatus 
will  find  their  investments  a  thousand  times 
repaid ;  and  as  for  those  who  cannot,  especially 
those  who  spend  their  lives  in  institutions  for 
the  blind,  we  can  only  hope  that  the  more 
fortunate  and  wealthy  will  appreciate  the 
unparalleled  opportunity  they  have  for  doing 
good. — The  Editor. 


learned  to  write  via  the  system  of  "hunt  and 
peck."  But  presently  telegraphy  lost  its 
charm  as  a  vocation  for  a  young  man  of 
such  powerful  physique.  He  was  very  ac- 
tive. He  must  be  out  of  doors,  and  so  on 
the  24th  day  of  October,  1896,  he  became  a 
member  of  New  York's  guardian  police  force. 

Little  could  Officer 
O'Keefe  realize,  when 
he  plunged  into  that 
dark  tenement  hall  to 
investigate  the  cause 
of  the  disturbance, 
that  those  few  mo- 
ments would  mark  the 
passing  of  his  sight. 
And  throughout  the 
following  twenty-four 
years,  or  until  the 
broadcasting  wave 
swept  over  the  land, 
little  did  he  dream 
that  he  would  travel 
to  foreign  shores  and 
enjoy  the  scenery- — • 
via  radio. 

The  other  evening  I 
called  upon  him  in 
his  Harlem  home  and 
heard  his  story.  And 
he  told  it  in  a  way 
that  only  a  man  who 
had  actually  lived  through  the  privations  of  the 
blind  could  possibly  have  told  it.  Not  a  man 
given  to  self-pity  and  complaint — on  the  con- 
trary, as  thoroughly  buoyant  in  spirits  and 
health  as  people  with  the  sense  of  sight,  perhaps 
more  so.  A  man  of  the  world,  with  a  strong 
grasp  of  the  hand  and  a  strong  grasp  on  the 
affairs  of  the  world.  For  as  he  sat  and  talked, 
and  laughed  and  smoked,  one  could  not  help 
seeing  that  he  had  a  feel  on  nature's  finer 
things. 

"Nature,"  he  said,  "has  some  wonderful 
compensating  laws.  When  a  man's  sense  of 
sight  is  taken  away,  the  remaining  senses  come 


A  Man  Who  Built  A  Set  He  Has  Never  Seen 


129 


to  the  rescue,  and  become 
ever  so  much  more  acute. 
And,  too,  the  loss  of  sight 
stimulates  caution,  easi- 
ness, patience — never  a 
loss  without  some  gain. 
Instead  of  the  eye  observ- 
ing a  panorama  of  things, 
a  man's  reason  becomes 
better  developed,  and  his 
nervous  energy  greatly 
conserved.  Of  course,  the 
loss  of  sight  is  a  great 
handicap,  but  I  soon  be- 
came accustomed  to  it. 
It  wasn't  long  before  I  was 
taking  long  hikes  to  West- 
chester, wrestling  with  the 
boys,  swimming,  fishing, 
and  otherwise  enjoying 
myself  in  the  sunshine  and 
air.  Several  years  after 
this  handicap  came  upon 
me,  I  married,  and  my 
wife  and  children  became 
the  joy  of  my  life. 

"  When  did  you  become 
interested  in  radio?"- the 
writer  asked. 

"Just  about  a  year  ago. 
Contrary  to  the  custom  of 
many  blind  folks  who  be- 
come more  or  less  clannish 
and  stay  by  themselves,  I 
have  always  mingled  with 
people  who  read  the  top- 
ics of  the  day.  Or  sometimes  friends  drop  in 
with  a  few  cigars  and  try  to  tease  me.  'What 
kind  of  a  cigar  is  this?'  they  will  ask,  just  to  see 
if  1  can  tell  by  the  aroma.  Or  else  they  will 
drop  in  to  tell  me  what  is  going  on  at  the  club. 
On  one  of  these  occasions  a  friend  told  me 
about  the  development  of  radio,  and  related 
someof  the  wonderful  things  that  could  betaken1 
out  of  the  air — concerts,  lectures,  travel  talks, 
stories,  baseball  scores,  and  code.  And  then 
my  boy  read  from  the  newspapers  what  was 
going  on  in  that  line.  I  didn't  know  very  much 
about  how  the  thing  worked,  but  the  thought  of 
listening  to  good  music  and  the  possible  educa- 
tional value  of  the  lectures  proved  entirely  too 
much  for  me,  and  I  determined  to  find  out  some- 
thing about  this  thing  and  to  build  myself  a  set. 

"In  my  early  days  I  had  studied  telegraphy 
and  of  course  became  familiar  with  batteries, 


OPERATING  THE  SET  HE  MADE  HIMSELF 
Mr.  O'Keefe,  lost  his  sight  twenty-four  years  ago.    "No  one  knows  the  amount  of 
good  I  get  out  of  this  little  set,"  he  says,  "and  no  one  can  know  but  myself,  for  it 
is  like  an  emotion — very  hard  to  explain" 


circuits  and  that  sort  of  thing.  And  I  under- 
stood a  good  deal  about  the  telephone.  So  it 
came  down  to  the  point  of  cost  and  actual  con- 
struction. Naturally,  in  my  circumstances  I 
had  to  confine  myself  to  a  crystal  set,  and  I  like 
the  crystal  very  much.  My  boy  read  to  me 
-how  to  make  the  primary  and  secondary  coils, 
how  to  mount  the  slide  tuner,  how  to  connect 
the  crystal,  coil,  condenser,  and  phones  in  the 
circuit,  and  gradually  1  began  to  visualize  in  my 
mind  just  how  the  thing  could  be  done. 

"Visualization  is  half  the  battle.  Also  I 
began  to  comprehend  inductance  and  capacity 
and  to  see  why  different  taps  had  to  be  taken 
from  the  secondary  in  order  to  tune  in  on 
different  wavelengths.  And  then  came  the 
condenser,  detector,  phones,  and  aerial — all  this 
I  got  firmly  in  my  mind  and  then  proceeded  to 
make  a  loose-coupler  type  of  set. 


Radio  Broadcast 


"  I  had  been  handy  with  tools  all  my  life,  and 
had  always  derived  a  great  deal  of  pleasure 
with  a  jack-knife.  In  fact,  one  of  the  first 
things  I  made  after  I  lost  my  sight  was  a 
wooden  chain  which  I  had  whittled  out  of  a 
stick,  and  the  keeper  of  the  hotel  where  I  was 
staying  up  in  the  Catskills  liked  it  so  much  that 
he  had  it  gilded  and  hung  on  the  wall — not 
because  of  the  beauty  of  the  thing,  perhaps,  but 
because  a  blind  man  had  made  it.  That  called 
for  vizualizing  a  chain,  and  very  careful  carving 
in  order  to  avoid  spoiling  the  links.  Then  again 
some  of  the  neighbors  have  brought 
in  their  clocks  for  me  to  fix,  and  other 
similar  jobs,  so  all  in  all  I  have  kept  2|f^ 
in  pretty  good  trim.  And  with  it  I  ijjjiBj^ 
developed  a  sense  of  proportion  and  (Brjj|i 
design,  and  as  I  set  about  the  task  of  Vfejigii 
building  my  radio  set  I  could  see  it  \^~-r* 
being  developed  step  by  step — see  it 
almost  as  well  as  a  man  with  eyes. 

"  Dimensions  of  course  were  the  principal 
thing.  The  secondary  had  to  fit  into  the 
primary.  1  had  to  make  calculations  for  the 
end  boards,  the  stand  it  was  to  rest  on,  wire  the 
coils,  bolt  on  my  condenser,  the  detector, 
insert  my  posts,  connect  to  the  aerial  and  so  on. 
The  set  you  see  here  is  a  loose-coupler  type 
crystal  set  with  a  43-plate  condenser  shunted 
across  the  secondary.  It  was  the  first  set  1 
built,  but  since  then  1  have  built  three  others — 
one  for  a  girl  across  the  street  and  two  others 
for  boys.  1  enjoy  it  immensely — there  is 
nothing  like  being  employed,  no  matter  whether 
you  are  blind  or  not.  It  saves  people  from 
brooding  and  pitying  themselves — self-pity 
is  the  worst  affliction  that  can  befall  a  man. 
What  I  have  done,  others  can  do,  and  they  will 
be  all  the  better  for  it,  and  if  you  publish  this 
interview  I  hope  it  will  reach  the  ears  of  blind 
folks  so  that  they  may  learn  of  the  advantages 
of  radio. 

"  First,  in  the  actual  construction  of  my  set, 
I  started  with  the  base  board,  visualizing  where 
the  coils  ought  to  be,  the  condenser,  the  detec- 
tor and  where  the  lead-in  and  ground  posts 
should  be.  I  sawed  this  board  from  the  solid 
end  of  a  box,  using  a  square  to  get  the  saw 
started  straight,  and  applying  it  frequently  to 
the  board  to  learn  if  1  was  making  a  good  job. 
Then  for  legs  for  the  set  I  got  hold  of  four  base- 
board bumpers  that  folks  sometime  screw  onto 
a  door  near  the  bottom  to  prevent  the  knob 
bruising  the  wall  paper  and  plaster.  Besides 
being  about  the  right  height — three  inches  or  so 


— they  have  rubber  tips  and  come  so  nicely 
carved  all  ready  to  screw  on  that  one  wouldn't 
want  anything  better  for  legs.  Then  1  sand- 
papered them  and  set  about  building  my  coils. 

"  That  is  where  one  of  the  things  belonging 
to  my  wife  came  in — the  much  abused  rolling 
pin.    Besides  proving  wonderful  kitchen  night- 
sticks and  pie-crust  rollers,  they  are  ideal  for 
the  winding  of  a  coil — at  least,  it  was  so  with 
me.    My  boy  got  a  soap  box  for  me  and  1  cut 
out  a  small  section  on  both  sides,  about  two 
inches  deep,  to  form  sockets  for  the  ends  of  the 
rolling  pin  to  fit  in.    In  a  way,  this 
j^gg"*'     acted  as  an  improvised  lathe.  Then 
SBB^      I  ran  the  rolling  pin  through  the  card- 
board  cylinder  on  which  was  to  be 
^aH]    wound  the  coil.    This  proved  a  very 
fiJ^iSgr/     good  fit,  and  when  the  pin  was  set  in 
^r^W      the  niches  of  the  box  I  could  turn  it 
S^is^       very  steadily  and  evenly  with  one 
hand  and  guide  the  wire  with  the 
other,  and  thus  I  wound  my  primary  coil.  The 
secondary  of  course  was  a  little  harder  proposi- 
tion because  I  had  to  jab  holes  through  the 
cardboard  with  a  hat  pin  every  ten  loops  and 
lead  the  wire  ends  through,  for  taps  to  the 
switch  points. 

"The  end  board  itself  was  a  little  difficult 
to  make  because  I  did  not  have  an  auger  large 
enough  to  bore  a  3i-inch  hole.  But  my  youngs- 
ter had  one  of  those  model  building  sets  with 
which  you  can  build  towers  and  bridges  and 
things.  In  this  set  were  several  small  pieces  of 
steel  with  a  number  of  perforated  holes  half  an 
inch  apart.  Taking  two  pieces  of  steel,  I  set 
an  old  Gillette  safety-razor  blade  between  them 
and  bolted  the  steel  and  blade  together.  Little 
axles  and  collars  also  come  with  a  building  set, 
so  I  screwed  a  collar  to  the  board,  saw  that  my 
safety-razor  blade  was  if  inches  away,  or  half 
the  diameter  of  the  hole,  and  then  swung  it 
round  and  round  like  a  compass  knife,  cutting 
deeper  and  deeper  each  time  until  finally  I  had 
cut  all  the  way  through  the  board.  Right 
here,  however,  comes  a  joke  on  me — after  1 
had  spent  the  best  part  of  a  day  making  that 
3^-inch  hole,  I  found  out  I  could  have  bought 
an  end  board  with  a  hole  already  in  it  for  five 
cents!  But  1  had  the  fun  of  figuring  out  a 
device  for  making  it,  anyway. 

"  The  next  step  was  to  mount  the  condenser. 
This  called  for  holes  to  be  drilled  in  order  to 
bolt  the  blade  part  to  the  meter  scale.  Drilling 
holes  straight  was  a  little  difficult,  but  I  man- 
aged to  do  it  with  the  aid  of  a  cardboard  pat- 


A  Man  Who  Built  A  Set  He  Has  Never  Seen 


tern  and  a  good  deal  of  patience.  The  holes 
had  to  be  straight  in  order  to  make  the  two 
parts  jibe,  and  1  certainly  wanted  the  set  to 
look  as  though  a  workman  had  constructed  it, 
and  if  it  looks  the  way  I  have  visualized  it,  it 
must  be  O.  K. 

"  Finding  a  sensitive  spot  on  the  crystal  also 
proved  a  tedious  proposition.  Finally  I  got  it 
with  the  aid  of  a  buzzer, 
which  also  lets  me  know 
whether  my  tuner  is  in  con- 
tact with  the  coil  or  not. 
Funny  thing  about  these 
crystals.  They  seem  very 
temperamental  and  shy. 
You  never  know  where  a 
sensitive  spot  might  be,  and 
after  you  get  it  you  never 
know  the  reason  why.  I  re- 
member working  practically 
the  whole  of  one  evening 
trying  to  find  a  sensitive 
spot  on  my  crystal  and  was 
about  to  give  it  up  and  go 
to  bed  when  a  sudden  little 
jar  with  my  knee  found  the 
sensitive  spot  for  me.  I  had 
the  phones  on  my  ears,  and 
right  away  got  the  surprise 
of  my  life.  1  was  tuned  in 
at  360  meters  and  the  first 
thing  I  heard  was  the  name  'Patrick'  coming 
over  in  code.  Patrick  is  my  name,  but  why  it 
should  be  the  first  thing  to  come  through  or  who 
sent  it  I  do  not  know.  Anyway,  Patrick  had 
found  the  sensitive  spot  on  the  crystal,  and  Pat- 
rick sat  up  until  way  long  into  the  night  listening 
to  one  of  the  best  concerts  he  had  ever  heard." 

Thereupon  Mr.  O'Keefe  went  on  to  tell  of  his 
experience  with  aerials.  His  first  aerial  was  a 
wire  that  he  ran  out  on  the  pulleys  of  the  family 
clothes  line.  This  proved  rather  weak.  Then 
he  tried  running  a  wire  around  the  house,  and 
on  the  roof  of  the  house,  but  it  was  dangerous 
for  him  to  walk  around  an  unguarded  roof. 
Finally,  he  came  to  the  use  of  a  device  which  he 
screws  into  an  electric  light  socket,  the  wiring 
circuit  of  the  house  acting  as  the  aerial.  This 
system  has  given  excellent  results,  and  inasmuch 
as  he  uses  a  condenser  which  is  shunted  across 
the  secondary,  and  also  a  phone  condenser,  he 
is  able  to  tune  quite  sharply.  Altogether,  his 
is  one  of  the  best  arranged  home-made  crystal 
sets  that  the  writer  has  ever  seen,  neatly  con- 
structed and  yet  as  simple  as  can  be. 


"Painting  was  the  only  part  of  the  work  I 
didn't  do  myself,"  he  said.  "  1  wanted  the  set 
to  look  O.  K.,  and  while  I  could  gather  how  it 
looked  by  the  feel,  I  could  not  paint  that  way — 
that  is,  I  didn't  want  to  be  putting  my  fingers  on 
the  painted  surface  to  guide  me  in  the  work,  so 
my  boy  painted  it  for  me." 

"What  was  the  total  cost  of  the  set?"  I  asked. 


THE  CRYSTAL  SET  WHICH  MR.  O  KEEFE  MADE  BUT  HAS  NEVER  SEEN 
It  is  almost  inconceivable  that  a  man  who  is  totally  blind  can  build  a  complete  radio 
set  unassisted,  including  winding  the  coils,  and  doing  all  the  wood  working.  The 
secondary  was  wound  over  a  rolling-pin;  the  legs  of  the  platform  are  door- 
stops. Mr.  O'Keefe  cut  the  35"  hole  in  the  loose-coupler  end-piece  with  an  impro- 
vised device  employing  a  safety  razor  blade 


"A  little  less  than  $5.00,"  was  the  reply. 
"  The  condenser  was  the  most  expensive  part  of 
it,  but  it  is  worth  all  it  cost  as  it  helps  me  to 
tune  out  a  station  I  don't  happen  to  want.  The 
phones  are  only  a  makeshift,  but  I  make  them 
do.  The  whole  outfit  gives  very  good  satisfac- 
tion, and. of  course  I  get  more  than  an  ordinary 
amount  of  pleasure  out  of  it  on  account  of  hav- 
ing made  it  myself." 

The  ex-policeman  leaned  back  in  his  chair  and 
puffed  contentedly  at  a  cigar.  He  was  sitting 
in  his  "corner,"  or  as  his  wife  terms  it,  his 
"workshop."  Directly  overhead  were  his  po- 
lice department  certificates.  On  one  side  of 
the  chair,  next  to  the  mantel  of  the  fireplace, 
stood  a  little  table  covered  with  tools,  wire,  and 
other  odds  and  ends,  and  attached  to  this  table 
was  a  swinging  board  supporting  his  present  set. 
It  is  always  within  reach,  and  pretty  nearly  al- 
ways in  use.  For  wherever  broadcasting  is 
taking  place  in  the  metropolitan  area  here  is 
one  man  quite  willing  to  listen. 

Next  to  his  chair  stood  a  little  stool  on  which 
were  several  magazines  for  the  blind,  printed  in 


132 


Radio  Broadcast 


Braille,  or  the  raised-dot  system,  various  com- 
binations of  dots  representing  different  letters 
in  the  alphabet.  But  1  learned  from  Mr. 
O'Keefe  that  there  is  nothing  in  the  literature 
for  the  blind  pertaining  to  radio.  He  said  this 
was  most  unfortunate,  for  of  all  people  in  the 
world  who  stand  to  benefit  from  radio  the 
blind  would  probably  head  the  list. 

"  1  do  not  like  to  ask  my  wife  and  children  to 
sit  down  and  read  to  me,  "  he  explained.  "  The 
wife  has  her  family  work  to  do  and  the  children 
have  to  prepare  their  school  lessons,  and  it 
would  be  selfish  on  my  part  to  take 
up  much  of  their  time.  No,  1  enjoy 
sitting  here  a  couple  of  hours  at  a 
time  listening  to  what's  going  on  in 
the  world.  No  one  knows  the  amount 
of  good  I  get  out  of  this  little  set,  and 
no  one  can  know  but  myself,  for  it  is 
like  an  emotion — very  hard  to  ex- 
plain. 1  am  a  great  lover  of  music, 
and  certainly  get  the  concerts  very 
clear — that  is,  unless  some  fellow  with  a  tube 
set  allows  it  to  oscillate  and  send  out  a  flock  of 
'  birdies.'  But  that  doesn't  happen  very  often, 
for. I  tune  pretty  sharply,  and  generally  succeed 
in  tuning  them  put.  Music  has  a  wonderful 
effect  on  me — simply  lifts  me  right  out  of  every- 
thing, and  before  radio  came  in  I  used  to  make 
a  lot  of  it  myself. 

"The  trips  you  can  take  via  radio  are  certainly 
great.  ,  A  short  time  ago  the  advertising  man- 
ager of  the  American  Express  Company  gave  a 
series  of  travel  talks  on  tours  in  foreign  lands — 
and  I  went  with  him.  1  could  visualize  the 
foreign  peoples  he  described,  their  ways  of  liv- 
ing, and  every  bit  of  the  wonderful  scenery. 
The  Company  never  knew  how  much  I  enjoyed 
that  trip!-  I  have  gone  completely  around  the 
world,  and  it  didn't  cost  me  a  cent.  And  then  I 
went  down  to  the  dock  on  the  East  River  and 
talked  with  an  old  salt  who  has  been  in  every 
port  in  the  world,  one  of  those  fellows  who  can 
describe  things  beautifully,  and  he  went  more 
into  detail  about  the  different  places.  But 
wasn't  he  surprised  when  I  began  to  tell  him  all 
about  Australia?  He  wondered  how  the  deuce 
I  knew! 

"  But  the  best  sport  of  all  comes  from  people 
who  don't  know  they  are  broadcasting.  For 
instance,  at  some  of  these  banquets,  the 
speeches  are  picked  up  by  microphone  and  re- 


layed to  a  station  to  be  broadcasted.  Now  the 
average  man  doesn't  know  how  sensitive  a  mi- 
crophone  is,  and  unwittingly  [two  or-  three  fel- 
lows sitting  near  the-  microphone  will  discuss 
the  ladies  and  drop  whispers  to  one  another  in 
a  confidential  tone.  And  away,"  perhaps  for 
thousands  of  miles, , those  little-confidences  will 
be  wafted  by  the  radio  waves  to  fall  on  listening 
ears. 

"At  one  or  these  formal  gatherings  the  toast- 
master  announced  that  Charles  M.  Schwab 
would  speak.  Mr.  Schwab  gave  a  very  fine 
address,  and  during  the  course  of  it 
he  commenced  to  laugh.  That  laugh 
tickled  me,  and  1  remembered  it.  One 
evening  I  heard  the  same  laugh  again, 
and  1  said  to  my  wife,  'My  friend 
Charlie  Schwab  is  here,'  and  sure 
enough  he  was  afterward  introduced 
to  speak.  He  had  evidently  been 
sitting  near  the  microphone,  unaware 
that  people  with  phones  over  their 
ears  were  enjoying  the  merrymaking  too. 

"The  world's  series,  the  big  football  games, 
the  horse  races — all  the  sports  come  to  me 
through  the  air.  Last  summer,  a  friend  of 
mine  dropped  in  and  1  began  telling  him  all 
about  the  ball  game.  'How  did  you  hear  about 
it?'  he  asked.  He  had  been  to  the  game  that 
very  afternoon  himself,  and  had  got  soaking 
wet  in  the  rain,  whereas  I  sat  here  perfectly 
contented  and  heard  Grantland  Rice  say  'Now 
the  pitcher vis  winding  up,  and  now  he  lets  it 
go.'    And  I  didn't  get  wet,  either. 

"Of  course,  my  machine  is  limited  to  a 
radius  of  about  25  miles — the  more  powerful 
sets  bring  in  the  far-away  station,  but  I  get 
as  much  as  I  want  at  that.  Next  summer  a 
friend  and  I  are  going  fishing  along  the  North 
Shore,  and  I  am  certainly  going  to  take  my 
little  set  along  and  rig  up  an  aerial  on  the 
boat. 

Yes,  indeed,  radio  is  a  wonderful  boon  to 
humanity,  and  I  look  forward  to  still  greater 
things.  Somehow  I  think  that  an  artificial  sense 
of  sight  could  be  stimulated  in  people  who  have 
lost  the  sight  of  their  eyes.  1  haven't  any 
worth-while  suggestions  to  offer,  but  perhaps 
someone  who  knows  more  about  radio  than  I 
do  will  discover  a  method.  In  the  meantime, 
let  the  blind  be  thankful  that  radio  is  at  hand — 
and,  also,  let  them  use  it." 


A  Loop  Receiver  in  the  Tropics 

By  CHARLES  T.  WHITEFIELD 


I WONDER  if  many  fans  have  had  the  fun 
from  a  receiver  which  has  been  given  us  by 
our  loop  machine.  We  found  it  a  not 
considerable  package  to  carry  with  us  on 
the  steamer  from  New  York,  and  forthwith 
set  it  up  on  deck  and  attended  New  York  con- 
certs and  church  services  on  Sunday  to  the 
enjoyment  of  the  passengers. 

The  apparatus  failed  us  in  only  one  particu- 
lar. When  we  moved  it  to 
the  salon,  which  is  well 
below  decks,  it  refused  to 
speak— doubtless  too  much 
steel  between  it  and  the 
outer  world.  - 

From  Nassau,  in  the  Brit- 
ish West  Indies,  we  get 
everything  2,000  miles  and 
less  north,  south,  east,  and 
west  during  the  evening, 
and  find  it  most  difficult  to 
get  good  signals  in  the  day- 
time; but  at  night  the  con- 
certs and  lectures  come 
most  clearly  and  the  news 
we  pick  up  from  WOO, 
Philadelphia,  is  a  godsend 
when  news  is  scarce  and 
from  three  days  to  a  week 
late. 

Perhaps  our  most  amus- 
ing experience  was  to  take 
the  machine  to  one  of  the 
"Out  Islands,"  so  called, 
where  wireless  was  never 
heard  of  and  the  natives 
were  skeptical  and  supersti- 
tious. When  we  asked  them 
if  they  would  like  to  go  to  a 
church  service  held  in  New 
York,  they  showed  small  in- 
terest in  such  "foolish talk"; 
but  when  the  voice  of  the 
minister  was  heard  and  the 
hymns  sung  by  the  congre- 
gation they" '  thought  the 
end  of  the  world  was  upon 
them.  They  did  not  at 
first  enjoy  the  exper- 


ience— looked  for  telegraph  wires,  and  finally 
gave  up  in  despair  as  to  how  the  trick  was  done. 

But  in  the  Bahamas,  as  elsewhere,  radio  is 
making  its  way.  A  year  ago  there  was  not  a 
listening-in  amateur  in  these  islands.  This 
year  there  are  well  on  to  six  or  eight,  and  the 
art  is  spreading.  People  away  from  the  cen- 
tres where  batteries  and  parts  are  sold  have  no 
easy  time  of  it.    In  all  the  islands  you  cannot 


OPERATING  THE  LOOP  RECEIVER  IN  NASSAU,   B.  W.  I. 


134 


Radio  Broadcast 


buy  a  tube,  a  battery,  or  a  head  set,  or,  indeed, 
any  essential  part  of  a  radio  machine  beyond 
wire,  and  sets  are  at  a  premium.  But  that  con- 
dition is  changing  rapidly  because  of  the  great 
opportunities  to  hear  the  outer  world  perform 
in  a  manner  which  has  never  been  heard  of 
before. 

Common  report  has  it — and  it  is  no  doubt 
true — that  the  Bahamas  are  the  very  home  of 
static,  and  most  amateurs  shut  up  shop  in 
April  and  do  not  expect  to  listen  in  again  until 
November. 

1  have  found  the  loop  aerial  much  more  suc- 
cessful in  resisting  static  than  outside  aerials. 
As  a  matter  of  fact,  so  far,  to  April  ist,  it  has 
bothered  us  not  "  too  much,"  as  the  natives  say. 
The  one  thing  that  puts  us  completely  out  of 
business  is  the  wireless  station  on  the  hill  at 
Nassau.  When  it  starts  in  to  tick  off  messages 
to  Miami  180  miles  away  at  over  30  cents 
a  word  it  settles  down  and  drowns  us  out  like 
flashes  of  lightning,  and  we  must  shut  up  our 
telephone  headpieces  until  the  messages  are 
complete. 

As  in  England  and  all  British  Colonies  one 
can  not  possess  and  operate  a  receiving  instru- 
ment without  a  license,  and  a  license  is  a  serious 
matter.    You  must  apply  in  writing,  and  the 


matter  is  then  taken  up  "on  behalf  of  the 
Governor  in  Council,"  and  after  two  weeks 
or  so,  if  you  appear  to  be  a  reliable  person  in 
good  standing,  you  receive  an  involved  docu- 
ment of  three  pages.  With  the  license  comes 
a  bill  for  five  shillings  for  a  year's  use  of  the 
machine,  and  you  are  at  liberty  to  proceed. 

When  we  set  up  our  machine  there  was  some 
question  about  the  risk  of  stringing  wires  be- 
cause of  lightning,  etc.  When  it  was  found  out 
that  our  set  required  no  wires  and  gave  no  sign 
outside  of  the  house,  "  The  Governor  in  Coun- 
cil "  was  perplexed,  this  being  the  first  loop  set 
ever  set  up  in  the  Islands. 

One's  pleasure  is  often  heightened  when  clear 
and  loud  signals  come  in  from  northern  cities 
that  they  are  suffering  from  a  blizzard  and  the 
performers  had  difficulty  in  getting  to  the 
station  because  of  the  storm,  while  we  sit  here 
in  our  lightest  clothes,  with  windows  and  doors 
open  to  catch  the  evening  breeze.  But  we 
hear,  too,  from  the  South.  A  few  nights  ago 
we  searched  about  for  the  news  bulletin  and, 
failing,  got  Porto  Rico,  and  were  informed  to 
our  great  delight  that  world  news  would  be 
distributed.  We  listened  with  all  our  ears, 
only  to  hear  it  all  in  Spanish,  of  which  not  a 
soul  in  the  room  understood  a  word. 


PUTTING  "THE  TRAVELING  SALESMAN"  ON  THE  AIR  AT  WGY,  SCHENECTADY 
The  scene  is  laid  in  a  small  railroad  station — hence  the  telegraph  instrument.    The  director's  phones,  padded  to  exclude 
all  local  sounds,  are  connected  to  a  set  outside  which  is  tuned  to  the  concert.    By  holding  up  printed  cards,  he  can  inform 

the  players  how  they  are  "registering" 


With  the 
Broadcasters 


GRAIN   PRICES  GOING  OUT 
This  ticker  at  WLAG  reports  the  prices  of  cash  grain 
and  grain  for  future  delivery  from  the  Exchange 
Room  of  the  Minneapolis  Chamber  of  Commerce 


EDITH  BENNETT 
Who  sang  to  Europe  from  WOR,  the  Bam- 
berger store  at  Newark,  N.  J.    She  is  con- 
sidered by  many  as  the  finest  radio  singer 


GANNA  WALSKA 
Grand  Opera  singer,  the  wife  of  Harold 
McCormick,  broadcasting  from  the  Waldorf 
Astoria  studio  of  WJZ,  in  New  York  City 


THE  "HIRED  HAND 
Announcing  at  WBAP,  the  Star-Telegram  station  at 
Fort  Worth,  Texas.     He  is  president  of  the  Radio 
Truth  Society,  with  a  membership  of  10,000  fans 


Protecting  Your  Invention 

First  Aid  for  Those  Struck  by  Patentable  Ideas 
By  ROGER  SHERMAN  HOAR 

Former  Assistant  Attorney  General  of  Massachusetts 


"'0  ONE  will  deny  that  "'tis  better 
to  be  safe  than  sorry."  Suppose 
that  you  have  an  original  idea,  as 
^fc  some  day  you  may.  You  do  not 
™  think  that  it  amounts  to  much,  you 
have  no  intention  of  ever  patenting  it,  you  are 
even  reasonably  sure  that  it  isn't  patentable; 
and  yet  it  may  eventually  turn  out  to  be  very 
valuable.  Why  not  play  safe  and  protect  your 
invention  from  the  very  start?  The  fact  that 
you  are  the  original  and  first  inventor  will  avail 
you  nothing  unless  you  preserve  the  evidence 
to  prove  this  fact,  and  even  then  you  may  not 
be  safe  unless  you  take  certain  further  steps. 

Therefore,  the  moment  you  conceive  of  a  new 
and  useful  invention,  you  should  at  once  pre- 
pare an  "evidence  of  conception":  i.e.,  a 
sketch,  signed  by  the  inventor,  recording  the 
date  of  conception,  and  witnessed  by  two  per- 
sons, whose  endorsement  should  read  sub- 
stantially as  follows:  "(date)  Explained  to 
and  understood  by  (signatures)." 

Such  a  sketch  should  contain,  or  be  accom- 
panied by,  a  sufficient  written  description  to 
render  the  drawing  perfectly  clear  and  under- 
standable. 

This  paper  serves  several  purposes.  First, 
it  provides  you  with  two  witnesses  who  can 
prove  your  date  of  conception  and  date  of  first 
disclosure.  Then  too,  it  constitutes  your  first 
drawing  and  first  written  description.  Thus 
you  have,  in  a  single  document,  the  means  of 
answering  the  first  four  questions  which  will 
arise  in  any  interference  proceeding,  and  of 
proving  your  answer. 

There  are  many  persons  who  will  solemnly 
inform  you  that  an  evidence  of  conception  is 
invalid  unless  it  is  written  in  ink,  signed  by 
two  witnesses  and  acknowledged  before  a 
notary.  What  do  they  mean,  invalid?  An 
evidence  of  conception  is  not  a  Patent-Office 
form!  Furthermore,  it  has  no  foundation 
either  in  rule  or  in  statute. 

The  only  function  of  an  evidence  of  con- 
ception is  to  refresh  the  recollection  of  one  (or 
both)  of  the  witnesses,  so  that  he  can  testify 


to  the  dates  of  conception,  drawing,  description 
and  disclosure,  if  necessary,  and  can  make  that 
testimony  sound  a  little  more  plausible  than 
merely  his  own  uncorroborated  word. 

If  it  accomplishes  this  end,  the  most  informal 
paper,  written  in  pencil,  and  signed  by  a  single 
witness,  is  sufficient.  Even  a  single  witness, 
without  any  paper,  will  do,  if  he  has  a  good 
memory  and  tells  a  convincing  story. '  But, 
believe  me,  his  story  has  got  to  be  convincing! 
Over  three  hundred  witnesses,  produced  by 
Drawbaugh  to  prove  that  he  invented  the 
telephone  before  Bell,  failed  to  convince  the 
U.  S.  Supreme  Court,  because  not  one  of  the 
witnesses  had  had  the  device  explained  to  him 
by  Drawbaugh. 

So,  as  a  practical  matter,  rather  than  as  a 
legal  requirement,  the  more  formalities  that 
you  can  add,  within  reason,  the  safer  you  will 
be.  But  note  those  two  words:  "within  rea- 
son." Too  much  formality  is  apt  to  defeat 
itself  by  suggesting  to  the  Court  that  it  has 
been  faked  to  bolster  up  a  weak  case.  But  by 
far  the  worst  objection  is  that  the  greater  the 
formality  of  a  form,  the  less  often  will  an  inven- 
tor take  the  bother  to  use  it.  And  the  evidence 
of  conception  should  certainly  be  frequently 
used. 

Among  the  refinements  sometimes  employed 
is  the  following.  The  inventor  places  the  paper 
in  an  envelope,  has  the  notary  seal  it,  sends  it  to 
himself  by  registered  mail,  and  then  doesn't 
open  the  envelope  until,  if  ever,  it  is  presented 
in  court. 

It  is  important  not  only  to  prepare  an  evi- 
dence of  conception,  but  to  prepare  it  at  the 
earliest  possible  date.  Don't  wait  for  the 
complete  idea  to  develop,  but  draw  up  a  paper 
the  moment  you  have  the  first  hazy  outline  of 
your  invention.  Draw  up  other  papers  from 
time  to  time,  as  you  work  out  your  details.  The 
most  valuable  part  of  your  patent  will  be  its 
broad  general  claims,  and  these  will  be  ade- 
quately supported  by  your  first  general  idea. 

Your  next  consideration  should  be  to  use 
due  diligence  in  "reduction  to  practice,"  i.e., 


Protecting  Your  Invention 


'37 


in  either  building  an  actual  operative  machine, 
or  (what  is  equally  effective)  filing  a  patent 
application.  This  latter  is  called  "construc- 
tive" reduction  to  practice.  Under  certain 
circumstances  two  months'  delay  has  been  held 
lack  of  diligence;  and  eight  years  has  been  held 
diligence;  so  you  see  how  little  the  time  element 
has  to  do  with  the  question. 

If  you  apply  for  a  patent,  a  diligent  reduc- 
tion to  practice  is  sufficient  to  entitle  you  to 
claim  your  original  conception  date.  But,  if 
you  do  not  apply  for  a  patent,  you  will  have  to 
rely  on  your  first  bona 
fide  sale,  public  use  or 
publication.  A  fake 
sale  won't  do.  Hence 
the  importance  of  sell- 
ing, usingor  publishing 
as  early  as  possible. 
But  this  has  the  disad- 
vantage of  starting  the 
running  of  the  two- 
year  period,  after 
which  your  right  to 
apply  for  a  patent  is 
automatically  for- 
feited. And  in  the 
case  of  publication, 
there  is  the  additional 
danger  of  having  your 
write-up  construed  as 
a  dedication  of  your 
invention  to  the  pub- 
lic. So  be  sure  and 
include  in  your  write- 
up  a  statement  that 
you  intend  to  apply 
for  a  patent. 

On  the  whole,  there- 
fore, it  is  much  wiser  to 
apply  for  a  patent,  even  for  the  mere  purpose 
of  retaining  your  own  right  to  make  your  own 
invention.  But  if  you  are  sure  that  you  do 
not  want  a  patent,  you  can  effectively  play 
the  dog  in  the  manger  by  publishing  a  full 
account  of  your  invention  in  some  magazine. 
This  will  render  void  any  patent  thereafter 
conceived;  and  after  two  years  will  render  void 
any  patent  application  thereafter  filed,  even  if 
conceived  prior  to  your  publication. 

Beware  of  permitting  the  general  use  of 
your  device  prior  to  your  applying  for  a  patent, 
for  this  is  likely  to  be  construed  as  a  complete 
abandonment  of  your  invention. 

If  you  decide  to  apply  for  a  patent,  the  first 


point  for  you  to  settle  in  your  own  mind  is  just 
why  you  have  so  decided.  Is  it  because  of  the 
fundamental  value  of  the  patented  novelty;  or 
as  a  mere  scare-crow  to  keep  others  from  dupli- 
cating some  distinctive  but  not  particularly 
patentable  feature?  Is  it  to  protect  yourself 
in  manufacturing  your  own  device?  Is  it  as  a 
mere  feeler,  to  save  the  expense  of  an  attorney's 
search  of  the  prior  art ;  or  to  drag  others  into  an 
interference,  and  thus  ascertain  what  are  the 
latest  developments  along  certain  lines?  Is  it 
to  sell  the  patent,  or  to  secure  royalties?  Or 

is  it  for  some  other 
reason?  On  an  intelli- 
gent analysis  of  these 
questions,  at  the  out- 
set, will  depend  the 
handling  of  the  case 
to  the  best  advantage. 

Very  often,  if  your 
chief  desire  is  merely 
to  keep  some  one  from 
making  a  "Chinese 
copy"  of  your  ma- 
chine, you  can  secure 
a  "design  patent"  on 
itsartistic  appearance, 
even  though  the  ma- 
chine itself  possesses 
no  patentable  novelty. 
But  the  Patent  Office 
is  particularly  on  its 
guard  against  this 
subterfuge. 

If  you  decide  to  ap- 
ply for  a  patent,  you  or 
your  attorney  must 
prepare  a  drawing,  a 
petition,  a  specifica- 
tion, some  claims,  and 
an  oath.  These  must  be  gotten  up  in  exact  ac- 
cordance with  the  "  Rules  of  Practice,"  a  booklet 
distributed  free  by  the  Patent  Office.  It  would 
pay  every  inventor  to  have  a  copy  of  this  book- 
let, and  to  study  it  frequently.  As  to  whether  or 
not  to  have  a  lawyer,  and  what  kind  of  a  law- 
yer to  get,  see  next  month's  article. 

The  Patent  Office  has  some  very  technical 
compulsory  regulations  with  regard  to  draw- 
ings, which  regulations  can  be  found  in  the 
"  Rules  of  Practice."  Special  printed  bristol- 
board  blanks  can  be  purchased  through  almost 
any  stationer.  But  what  always  mystified  me 
about  these  blanks  was:  why  do  they  say 
"inventor"  and  "attorneys,"  when  in  my 


Patent,  Patent,  Who  s  Got  the 
Patent? 

It's  a  great  game,  according  to  Mr.  Hoar, 
but  you  must  know  how  to  play  it.  Many 
apparently  queer  tricks  are  practised  for  per- 
fectly sound  reasons. 
Do  you  know: 

Why  "most  patent  lawyers  intentionally 
make  several  serious  misprints  in  the  applica- 
tion?" 

Under  what  conditions  an  inventor  will 
address  and  mail  a  letter  to  himself? 

When  it  is  advisable  to  make  your  claims 
broad,  and  when  narrow? 

How  to  "smoke  out  a  lot  of  prior  art?" 
How  to  avoid  "the  danger  of  having  your 
write-up  construed  as  a  dedication  of  your  in- 
vention to  the  public?" 

This  is  the  third  article  in  a  series  of  four 
dealing  with  patents  in  a'  clear  and  practical 
manner.  The  other  articles  are  "What  Good 
Is  a  Patent?"  in  the  April  number;  "What  Can 
Be  Patented?",  last  month;  and  "Miscellane- 
ous Considerations,"  to  appear  in  Radio 
Broadcast  for  July.; — The  Editor. 


i  38  Radio  Broadcast 


"seein'  things  at  night" 


experience  there  is  usually  more  than  one 
inventor,  and  only  one  attorney? 

The  petition  is  a  brief  formal  request  for  a 
patent;  and,  if  the  applicant  has  a  lawyer,  con- 
tains his  power  of  attorney,  in  which  case  a 
twenty-five-cent  revenue  stamp  must  be  affixed. 

The  specification  usually  contains  a  state- 
ment of  what  a  hopeless  state  the  art  was  in 
before  you  came  along  and  saved  the  day  with 
your  epoch-making  idea,  a  summary  of  the 
principal  objects  of  your  invention,  an  explana- 
tion of  your  drawing,  a  description  of  how 
your  device  works,  and  some  general  language 
claiming  that  your  invention  is  not  limited  to 
the  specific  form  disclosed  by  you,  but  rather  is 
applicable  to  almost  anything  under  the  sun. 

The  claims  are  detailed  statements  of  every 
possible  combination  of  the  new  ideas  involved 
in  your  invention.  For  examples  of  specifica- 
tions and  claims,  study  some  recent  patent 
obtained  by  some  large  corporation,  active  in 
the  radio  patent  field. 

Ought  you  to  draw  the  claims  broad  or  nar- 
row? Broad  claims  are  useful  to  smoke  out  a  lot 
of  prior  art,  and  thus  show  the  inventor  exactly 
where  he  stands.  Also  to  drag  more  pending 
cases  into  interference,  and  thus  advise  you 
as  to  what  others  are  doing  in  the  same  field. 
Also  to  bring  into  the  record  some  prior  patent, 
which  you  are  afraid  that  you  infringe.  This 
last  is  often  a  very  important  consideration. 


You  will  see,  later  in  this  article,  that  one  of  the 
three  ways  of  avoiding  a  patent  cited  by  the 
examiner,  is  to  prove  that  your  invention  does 
not  infringe  it.  Your  argument  is  entirely 
one-sided,  as  the  owner  of  the  earlier  patent 
is  not  given  a  chance  to  present  his  case.  Thus 
you  may  be  able  to  get  a  Patent  Office  ruling 
to  the  effect  that  you  do  not  infringe  this 
patent,  and  this  ruling  will  have  great  weight 
in  your  favor,  if  you  are  ever  called  into  an 
actual  infringement  suit.  The  advantages  of 
trying  your  case  first  in  the  Patent  Office  are 
obvious. 

Entirely  apart  from  the  above  special  rea- 
sons for  making  your  claims  broad,  there  is  the 
general  reason  that  you  naturally  wish  to  get  as 
broad  a  patent  as  possible. 

But,  if  you  are  well  acquainted  with  the 
prior  art,  and  so  realize  just  how  far  you  can  go 
with  valid  claims,  it  may  be  desirable  to  draw 
your  claims  narrow,  for  purposes  of  speed  and 
a  clear  record.  The  advantages  of  a  clear  re- 
cord are  twofold.  First,  any  infringer  of 
your  patent  will,  of  course,  try  to  prove  that  it 
is  invalid,  and  his  first  step  will  be  to  secure, 
from  Washington  the  "file  wrapper"  of  your 
case,  i.e.  the  complete  record  of  office  actions 
and  amendments.  The  less  that  there  is  in 
your  file  wrapper,  the  less  starting  point  has 
your  enemy.  Secondly,  a  patent  with  a  clear 
file  wrapper  is  much  more  readily  salable  to  the 


Protecting  Your  Invention 


•39 


average  manufacturer,  due  to  his  ignorance 
of  patent  law;  although  personally  1  should  pre- 
fer the  very  fullest  record,  as  this  would  show 
that  we  were  getting  the  broadest  possible 
patent,  and  also  that  there  was  less  chance  of 
some  prior  art,  overlooked  by  the  examiner, 
cropping  up  later  in  the  courts. 

Even  when  you  can  secure  broad  claims,  it  is 
essential  that  your  patent  should  also  contain 
narrow  claims,  running  all  the  way  down  to 
claims  covering  every  nut,  bolt  and  screw  in 
the  utmost  detail.  The  reason  for 
this  is  that  if  your  patent  ever  gets 
into  litigation,  some  of  your  broadest 
claims  are  certain  to  go  by  the  board, 
and  you  should  be  prepared  to  con- 
test the  ground  foot  by  foot  as  you 
retreat.  Thus  the  succession  of  grad- 
ually narrowing  claims  exists  for  much 
the  same  reason  as  the  succession  of  first-, 
second-,  and  third-line  trenches  in  war. 

Be  sure  that  you  have  enough  claims  to  cover 
adequately  every  phase  of  your  invention,  but 
beware  of  having  too  many  claims.  "  Mul- 
tiplicity of  claims,"  as  it  is  called,  will  irritate 
and  antagonize  the  examiner,  and  if  your  patent 
ever  gets  into  court,  will  cause  the  judge  to 
interpret  it  most  narrowly.  But  a  basic 
patent,  or  one  which  represents  a  long  forward 
step,  is  entitled  to  many  more  claims  than  a 
patent  which  covers  merely  some  minor  im- 
provement. 

Usually  the  claims  of  a  patent  application  are 
rather  tentatively  drawn  at  first,  in  order  to 
sound  out  the  patent  examiner  and  see  what 
prior  art  he  can  discover.  After  the  Patent 
Office  has  passed  on  it,  your  attorney  will  be  in 
a  position  to  redraw  the  claims,  in  view  of  the 
prior  patents  which  the  examiner  has  produced. 
Therefore,  it  would  be  most  unfortunate  to 
have  an  application  allowed  right  off  the  bat. 
To  guard  against  this,  by  insuring  the  receipt 
of  at  least  one  adverse  office  action,  most 
patent  lawyers  intentionally  make  several 
serious  misprints  in  the  application. 

A  patent  application,  broadly  speaking,  con- 
sists in:  (1)  a  complete  disclosure  of  the  inven- 
tion, so  that  those  skilled  in  the  particular  art 
will  be  able  to  duplicate  it;  and  (2)  claims  as  to 
what  part  of  the  disclosure  the  inventor  wishes 
protected  by  the  patent. 

The  oath  asserts  that  you  are  the  original  and 
first  inventor,  and  denies  that  the  device  was 
known,  used,  published  or  patented  prior  to 
your  conception,  or  used  or  on  sale  in  the 


United  States  more  than  two  years  prior  to 
your  application,  or  patented  abroad  more 
than  one  year  prior  to  your  application. 

The  drawing  is  signed  by  the  attorney.  The 
petition  and  claims  are  signed  by  you.  The 
oath  is  signed  and  sworn  to  by  you.  The  filing 
fee  is  twenty  dollars. 

At  any  time  from  three  to  fifteen  months 
(according  to  how  far  behind  in  its  work  is  the 
division  of  the  Patent  Office  to  which  your  case 
happens  to  be  assigned)  you  will  receive  an 
"office  action"  pointing  out  the  mis- 
prints in  your  papers,  and  disallowing 
some  of  your  claims  for  lack  of  utility, 
or  for  incompleteness,  or  for  not  being 
supported  by  the  disclosure  in  your 
drawing  and  specifications,  or  for  be- 
ing "functional"  (i.e.  attempting  to 
cover  the  need,  or  result  or  effect  of 
your  device),  or  for  not  being  an  improvement 
over  the  "prior  art,"  in  which  latter  case  cer- 
tain earlier  patents  will  be  cited  against  you. 
The  examiner  may  require  you  to  divide  your 
application,  on  the  ground  that  it  contains 
matters  which  should  be  handled  by  two  sep- 
arate branches  of  the  Office.  In  rare  cases, 
some  of  your  claims  may  be  allowed. 

Within  one  year  of  the  action,  you  must 
"amend,"  i.e.,  file  a  paper  correcting  the  mis- 
takes, and  either  changing  your  drawing, 
specification  and  claims  to  meet  the  objections 
of  the  examiner,  or  else  arguing  with  him  in  an 
attempt  to  convince  him  that  he  is  wrong. 

There  are  three  ways  of  getting  around  a  cita- 
tion: (1)  amend  your  claim;  (2)  convince  the 
examiner  that  the  cited  patent  has  no  bearing 
on  your  invention;  or  (3)  convince  him  that 
your  invention  is  an  improvement  over  the 
other. 

If  you  get  away  with  No.  2,  you  are  clear  of 
the  other  patent.  If  you  get  away  with  No.  3, 
your  claim  will  be  allowed,  but  will  infringe 
the  other  patent,  if  it  is  still  alive. 

But  note  that,  although  the  claims  of  an  earl- 
ier patent  are  all  that  is  material  to  the  question 
of  infringement,  yet  either  the  drawing,  specifi- 
cation, or  claims  of  that  patent  may  decide  the 
question  of  anticipation:  i.e.,  whether  the  other 
fellow  beat  you  to  it. 

I  find  that  there  is  a  persistent  idea  among 
technical  men  that,  in  order  to  get  around  a 
prior  patent  which  is  cited  against  you  by  the 
Patent  Office,  it  is  necessary  to  file  some  sort  of 
paper  agreeing  to  hold  your  patent  subject  to 
this  prior  patent,  and  that  this  is  the  signif- 


140 


Radio  Broadcast 


icance  of  the  references  to  earlier  patents,  fre- 
quently found  in  printed  specifications.  But 
nothing  could  be  further  from  the  truth.  This 
mention  is  usually  either  for  the  purpose  of 
shortening  your  description,  by  referring  the 
reader  to  some  earlier  step  in  the  development 
of  the  art;  or  for  the  purpose  of  giving  to  a 
divisional  application  the  benefit  of  the  filing 
date  of  the  parent  case. 

An  application  becomes  abandoned,  if  the 
applicant  fails  to  reply  within  one  year  after  any 
office  action;  or  becomes  forfeited,  if 
he  fails  to  pay  the  final  fee  within 
six  months  after  allowance.    If  not  _^#r" 
prevented  by  some  other  considera-  /^pjii 
tion,  a  new  application  can  be  filed  flljlH 
in  place  of  an  abandoned  one;  and, 
if  filed  before  abandonment  is  com-  sajpjjj 
plete,  can  rely  on  the  filing  date  of 
the  original.    A  forfeited  application 
can  be  renewed  within  two  years  after  allow- 
ance. 

Division  of  an  application  is  affected  by 
striking  out  the  objected  claims,  and  then 
embodying  them  in  a  new  application. 

If  either  the  specification  or  claims  of  one  ap- 
plication covers  the  same  invention  contained  in 
either  the  specification  or  claims  of  another  ap- 
plication, the  Patent  Office  may  ask  either 
party  to  adopt  certain  claims  of  the  other  by 
amendment,  and  may  then  declare  an  interfer- 
ence, throw  open  the  files  of  each  party  to  the 
other,  and  require  evidence  as  to  which  party 
is  the  first  inventor.  But  before  doing  this,  the 
Patent  Office  frequently  requests  of  the  junior 
party  an  informal  statement  as  to  the  date  of 
his  conception,  and  if  this  date  is  not  earlier 
than  the  filing-date  of  the  senior  party,  no 
interference  is  declared. 

The  first  step  in  an  interference  is  the  pre- 
liminary statement,  the  contents  of  which,  and 
the  relative  value  thereof,  we  discussed  last 
month.  If  the  preliminary  statements  do  not 
prove  sufficient,  further  evidence  may  be  filed 
in  their  support,  but  no  inventor  will  be  allowed 
to  claim  any  dates  earlier  than  those  of  his 
statement,  except  for  extraordinary  reasons. 
The  disputed  claims  are  allowed  to  the  party 
who  proves  first  invention  coupled  with 
diligence  in  reduction  to  practice. 

An  interference  is  sometimes  declared  be- 
tween a  pending  application  and  a  patent  is- 
sued not  more  than  two  years  before  the 
application  was  filed.  The  grounds  are  slightly 
different  in  this  case,  for  only  the  claims  of  the 


issued  patent  are  considered.  But,  as  a  vic- 
tory for  the  applicant  will  not  result  in  cancell- 
ing the  prior  patent,  and  as  the  whole  matter 
will  have  to  be  fought  all  over  in  the  courts, 
it  may  be  well  for  the  applicant  to  avoid  inter- 
ference, and  insist  upon  the  issuance  of  his  own 
patent,  on  ex  parte  proof  that  his  conception 
was  earlier  than  the  other's  filing  date. 

In  handling  a  patent  case,  an  almost  un- 
limited amount  of  delay  is  possible.    Thus  you 
can  wait  nearly  a  year  after  each  office  action 
before  amending;  and,  in  order  to 
Jj^*'       guard  against  premature  allowance  of 
^jlilk     your  application,  you  can  keep  mak- 
MgifSn    ing  intentional   mistakes  in  every 
2«5eP§I|    amendment.    But  note  that  an 
'//y^/!  jj    amendment  which  does  not  represent 
a  bona  fide  attempt  to  meet  the  action 
of  the  examiner,  or  which  merely  re- 
iterates an  argument  once  rejected  by 
the  examiner,  will  not  prevent  the  case  from 
becoming  abandoned  through  one  year's  failure 
to  respond  to  an  office  action. 

The  chief  object  of  delay  is  to  extend  the 
date  to  which  your  patent  will  protect  you:  i.e., 
seventeen  years  from  the  date  of  issuance.  The 
later  your  patent  issues,  the  longer  it  will 
protect  you.  Thus,  in  the  absence  of  other 
considerations,  a  reputable  attorney  will  al- 
ways delay  as  much  as  possible. 

On  the  other  hand,  extreme  speed  may  be 
desirable  to  secure  immediate  protection 
against  infringement,  or  to  put  the  patent  in 
shape  for  a  speedy  sale  or  as  the  basis  for 
foreign  applications.  You  see,  a  foreign  ap- 
plication should  be  filed  within  a  year  of  your 
American  application,  and  should  be  drawn  in 
the  light  of  all  the  information  which  you  can 
possibly  glean  from  the  Patent  Office  as  to 
the  state  of  the  prior  art.    Hence  the  rush. 

But  inventors  are  apt  to  be  influenced  by  a 
very  natural  curiosity  to  learn  as  soon  as  possi- 
ble how  their  case  is  going  to  turn  out.  And 
lawyers  without  an  extensive  clientele  are  apt  to 
be  influenced  by  a  very  natural  desire  to  get 
their  pay  as  soon  as  possible.  Both  of  these 
tendencies  should  be  guarded  against. 

If  the  examiner  twice  rejects  a  claim  on  the 
same  grounds,  the  applicant  can  appeal  to  the 
examiners  in  chief  by  paying  a  %\o  fee.  From 
them,  a  $20  appeal  lies  to  the  Commissioner  of 
Patents;  and  from  him  a  %\  5  appeal  to  the  Court 
of  Appeals  of  the  District  of  Columbia.  Printed 
records  and  arguments  must  usually  be  fur- 
nished on  appeal. 


Protecting  Your  Invention 


141 


Beware  of  "double  patenting"!  Two  pa- 
tents cannot  be  obtained  by  the  same  person 
for  the  same  invention,  nor  can  a  broader  and 
more  basic  patent  be  obtained  by  the  holder  of 
a  more  detailed  or  more  advanced  patent.  In 
either  such  case,  if  the  second  patent  inadver- 
tently issues,  it  will  be  void.  So  it  is  impera- 
tive to  draw  your  first  application  so  as  to  cover 
everything  that  you  will  ever  wish  covered. 
Also  you  should  be  careful  not  to  let  some  sub- 
sidiary later  application  issue  before  your  basic 
one,  although  there  are  some  court  decisions 
which  hold  that  this  is  allowable. 

The  rule  against  double  patenting  has  even 
been  extended,  so  that  if  two  inventors  in  the 
same  field  assign  their  applications  to  the  same 
assignee,  and  if  a  patent  issues  on  the  narrower 
and  latest-filed  application,  then  this  patent 
will  prevent  the  issuing  of  a  patent  on  the 
broader  application,  although  first  filed.  This 
is  based  upon  the  fact  that  two  applications, 
owned  by  a  common  assignee,  cannot  be  put 
into  interference  with  each  other,  and  upon  the 
theory  that  the  choice  by  the  owner  to  let  one 
of  these  patents  issue  first,  is  equivalent  to  an 
adjudication  of  priority  in  favor  of  the  inventor 
of  that  patent. 

When,  by  numerous  amendments,  your  case 
has  at  last  been  put  in  condition 
for  allowance,  the  final  fee  of  $20 
must  be  paid  within  six  months. 
Thereupon,  on  the  fourth  Tuesday 
after  the  Thursday  after  your  fee 
was  received,  the  patent  will  issue 
and  will  be  published  in  the  next 
Official  Gazette. 

An  issued  patent,  from  which 
has  been  inadvertently  omitted 
some  important  claim  covered  by 
the  disclosure,  or  whose  disclosure 


is  insufficient  to  support  its  claims,  may  be 
surrendered  at  any  time  within  two  years  of 
issue,  and  a  petition  for  a  "reissue"  be  filed,  on 
which  the  procedure  will  be  very  similar  to 
the  procedure  on  an  original  application. 

If  an  issued  patent  claims  more  than  the  in- 
ventor is  entitled  to,  he  can  file  a  "disclaimer" 
of  the  excess.  Personally,  I  never  could  see 
any  particular  point  to  disclaimers.  True,  if 
you  sue  a  man  for  infringement,  and  he  can 
show  that  your  patent  was  too  broad,  then  the 
judge  will  not  award  you  your  costs.  But, 
even  so,  since  the  chief  value  of  a  patent  is  as  a 
scare-crow,  I  should  prefer  to  have  my  patents 
as  broad  as  possible,  and  take  a  chance  on  los- 
ing my  costs. 

In  the  foregoing  article  we  have  covered  not 
only  Patent-Office  procedure,  but  also  some 
phases  of  Patent-Office  tactics,  which  most 
inventors  think  should  be  left  strictly  to  their 
attorney.  Most  attorneys  think  this  too. 
But,  don't  you  believe  it !  Unless  the  inventor 
thoroughly  understands  the  tactics  of  his  case, 
he  will  not  be  able  to  decide  intelligently  the 
questions  which  his  attorney  puts  up  to  him, 
and  may  unjustly  blame  his  attorney  for  care- 
lessness, delay,  etc.,  when  these  may  happen  to 
be  exactly  what  the  situation  demands. 

Napoleon  once  said  that  he 
owed  his  success  to  his  knowledge 
of  tic  lacs.  When  asked  if  he  did 
not  mean  "tactics,"  he  said :  "No". 
He  ascribed  his  skill  in  getting  out 
of  difficulties  to  his  practice  of  put- 
ting tick-tacks  on  the  teachers' 
windows  and  then  not  getting 
caught.  So,  if  some  of  the  forego- 
ing article  savors  more  of  tick- 
tacks  than  of  tactics,  I  hope  that 
the  reader  will  excuse  me. 


Wanted — Information  on  Railroad  Radio 

The  Committee  on  Application  of  Radio  to  Moving  Trains  of  the  Association  of  Railway 
Electrical  Engineers  desires  to  communicate  with  any  one  who  can  give  information  regarding 
actual  experiments  in  radio  reception  or  transmission  to  or  from  a  moving  train. 

Kindly  communicate  with  the  Chairman  of  the  Committee, 

Mr.  P.  S.  Westcott, 

Assistant  Car-Lighting  Engineer, 

Chicago,  Milwaukee  &  St.  Paul  Ry.  Company, 

West  Milwaukee  Shops,  Milwaukee,  Wisconsin 


The  Search  for  a  Telephone  as 
Sensitive  as  the  Ear 


By  GEORGE  B.  GROUSE 

Chief  Engineer  of  the  Connecticut  Instrument  Co. 


*^HE  most  important  instrument  in 
radio  broadcast  systems  is  older  than 
the  pyramids,  as  old  as  the  race  itself. 
This  instrument  is  the  human  ear. 
To  say  that  the  ear  is  of  first  im- 
portance is  not  an  exaggeration,  for  to  you  no 
improvement  in  a  radio  device  would  be  of  the 
slightest  use  or  interest,  were  you  not  equipped 
with  ears.  It  is  of  first  importance  to  the  en- 
gineer, because,  he  can  neither  redesign  it  nor 
improve  it;  he  must  take  it  as  he  finds  it,  study 
its  characteristics,  and  build  all  the  rest  of  his 
apparatus  to  fit  its  needs. 

Even  aside  from  the  interest  which  this 
organ  holds  for  us  as  designers  and  users  of 
radio,  the  marvelous  ingenuity  and  delicacy 
of  its  construction,  its  accuracy  and  the  wide 
range  of  its  functions,  make  it  one  of  the  most 
fascinating  organisms  in  nature.  This  article, 
therefore,  has  for  its  purpose  the  explanation  of 
the  construction  of  the  ear  and  the  discussion 
of  some  of  the  problems  which  its  characteristics 
have  placed  before  the  designers  of  radio  tele- 
phone systems. 

Considering  the  functions  which  our  auditory 
apparatus  performs  for  us,  it  first  of  all  de- 
tects the  presence  of  sound  vibrations  in  the  air. 
Second,  it  determines  the  relative  loudness  of 
various  sounds  and  to  some  extent  the  actual 
loudness  of  a  single  sound;  we  say  sounds  are 
loud  or  soft.  Third,  the  ear  distinguishes  vari- 
ous kinds  and  qualities  of  sounds;  it  distin- 
guishes and  identifies  the  barking  of  a  dog, 
the  rattle  of  a  carriage  wheel  on  the  street,  the 
voices  of  our  friends:  the  trained  ear  will 
distinguish  the  difference  between  two  violins 
when  played  successively  by  the  same  man  in 
the  same  way.  Fourth,  our  two  ears  acting 
together  detect  roughly  the  direction  from 
which  a  sound  is  proceeding,  but  since  this  is  a 
function  which  is  not  of  much  interest  to  us  in 
radio,  we  will  not  consider  the  mechanics  of  its 
performance. 

Turning  now  to  the  devices  which  perform 
for  us  these  functions,  we  will  undertake  the 
explanation  by  designing  a  model  to  perform  in 


a  manner  similar  to  the  ear.  In  this  model 
we  shall  combine  elements  and  apparatus  or- 
dinarily used  in  radio  telephones. 

Historically,  it  is  undoubtedly  true  that  in 
the  lower  forms  of  life  the  auditory  apparatus 
performs  only  two  functions,  those  of  detecting 
and  roughly  measuring  the  loudness  of  a  sound. 
We  are,  therefore,  justified  in  dividing  our  ex- 
planation in  two  parts  and  considering  first  only 
these  two  functions. 

An  apparatus  for  these  purposes  would  logic- 
ally take  the  form  shown  in  Fig.  i  where  we 
have  a  horn  (i)  to  gather  up  and  concentrate 
the  sound  waves  at  its  small  end,  where  they 
cause  a  diaphragm  (2)  to  vibrate.  On  the  cen- 
tre of  this  diaphragm  is  placed  a  carbon  micro- 
phone (3).  This  is  the  device  ordinarily  used  in 
telephone  transmitters  and  its  function  is  to 
vary  its  resistance  in  unison  with  vibrations 
applied  to  it.  We  connect  this  microphone  in 
circuit  with  a  dry  battery  (4)  and  the  primary 
winding  (5)  of  a  transformer.  This  trans- 
former may  be  an  audio-frequency  transformer 
taken  from  a  radio  set.  Now  when  the  current 
in  this  primary  winding  varies,  due  to  the  varia- 
tion in  resistance  of  the  microphone,  it  causes 
a  proportional  alternating  current  to  flow  in  the 
secondnary  winding  (6)  and  we  measure  this 
alternating  current  with  the  meter  (7).  Then 
we  have  a  complete  instrument  for  detecting 
the  presence  of  a  sound  falling  on  the  diaphragm 
and  for  measuring  its  loudness  on  the  scale  of 
the  meter. 

This  sounds  simple  enough  until  we  remem- 
ber that  for  this  apparatus  to  be  the  equal  of 
the  human  ear,  it  must  be  capable  of  detecting 
a  motion  of  the  air  of  one  thousandth  of  a  mil- 
lionth of  an  inch,  while  at  the  other  extreme, 
it  must  not  be  overloaded  by  air  motions  ten 
thousand  times  as  great. 

In  order  to  perform  the  third  function  of 
analysing  and  determining  the  character  of  a 
sound,  our  model  will  become  much  more  com- 
plex and  its  explanation  requires  a  short  digres- 
sion to  consider  the  character  of  sound  waves. 

You  remember  in  your  class-room  days,  that 


The  Search  for  a  Telephone  as  Sensitive  as  the  Ear 


'43 


in  the  physics  course,  the  principle  of  reson- 
ance was  demonstrated  by  setting  up  a  tuning 
fork  (Fig.  2)  which  was  not  vibrating  and 
bringing  near  it  a  second  identical  fork  which 
was  sounding.  After  a  while  the  fork  which 
originally  was  not  vibrating  was  found  to  be  in 
motion.  This  motion  was  set  up  by  the  energy 
of  the  sound  waves  proceeding  from  the  second 
fork.  If  the  two  forks  were  not  exactly  alike, 
the  motion  would  not  be  transferred  from  one 
to  the  other.  The  principle  is  the  same  as 
when  a  church  bell  or  an  old-fashioned  swing  is 
set  in  motion  by  applying  small  impulses  at 
exactly  the  right  time. 

Now  to  set  a  tuning  fork  in  vibration  by 
means  of  sound  waves  falling  on  it,  the  sound 
must  have  exactly  the  same  pitch  as  the  pitch 
of  the  fork,  but  this  sound  need  not  be  gener- 
ated by  another  tuning  fork.  It  may  come 
from  a  piano  string,  the  human  voice,  a  pipe 
organ,  or  any  other  source.  However,  if  we  use 
say  a  piano  string  to  set  the  fork  vibrating, 
it  will  be  found  that  the  sound  will  set  forks  of 
several  different  pitches  vibrating.  On  the 
other  hand,  if  our  source  of  sound  is  an  open 
diapason  organ  pipe,  only  one  size  fork  will  be 
found  to  move.  This  is  due  to  the  fact  that 
the  sound  of  a  piano  is  "compound"  or  made 
up  of  a  number  of  simple  sounds,  whereas  the 
sound  of  the  open  diapason  organ  pipes  is  pure. 
Practically  all  sounds  are  compound  and  their 


ber  of  them  would  be  required.  If  while  a 
sound  acts  on  these  forks,  we  observe  which  of 
them  have  been  set  in  vibration  and  to  what 
extent,  we  have  an  accurate  knowledge  of  the 
character  of  the  sound. 

Now  the  ear  employs  just  this  principle.  It 
contains  a  series  of  bodies  which  like  the  tun- 
ing forks  are  capable  of  vibrating  at  one  pitch 
and  one  pitch  only.  The  incoming  sound  acts 
on  these  bodies  and  sets  the  proper  ones  in 
vibration  and  the  nerve  terminals  determine 
the  amount  of  the  motion. 

Before  we  proceed  to  build  this  principle 
into  our  model,  however,  we  must  examine  the 
properties  of  the  ear  a  little  more  closely.  When 
one  actually  tries  the  experiment  with  the  tun- 
ing forks  it  is  apparent  that  a  certain  length  of 
time  is  required  to  set  the  fork  in  vibration  by 
resonance  and  that  the  motion  when  once  set  up 
persists  for  some  time  after  the  cessation  of  the 
sound  which  caused  it.  Now  we  know  that  in 
the  ear,  the  response  and  analysis  is  almost 
instantaneous  and  that  a  sound  ceases  to  be 
heard  very  quickly  after  the  sound  itself  has 
ceased.  If  this  were  not  so  we  would  be 
totally  unable  to  follow  a  fast  conversation  or  a 
rapidly  executed  piece  of  music:  the  syllables 
and  notes  would  run  into  each  other  and  be- 
come confused. 

For  this  reason  we  must  find  some  way  of 
causing  the  sound  to  affect  the  forks  quickly 


FIG.  I 

Apparatus  for  detecting  and  roughly  measuring  the  loudness  of  a  sound 


character  is  determined  by  the  number  and 
relative  loudness  of  the  various  simple  sounds 
which  they  contain. 

Therefore,  if  we  wish  to  determine  the  charac- 
ter of  a  sound  we  have  to  analyze  it  and  deter- 
mine the  pitch  and  relative  loudness  of  the 
various  simple  sounds  which  it  may  contain. 
For  this  purpose,  we  might  use  a  battery  of  tun- 
ing forks,  upon  which  the  sound  to  be  analyzed 
is  allowed  to  fall.  Each  of  these  forks  would 
differ  from  the  other  in  pitch  and  a  great  num- 


and  of  quickly  stopping  their  motion  after  the 
sound  has  ceased.  The  way  in  which  this  is 
accomplished  in  the  human  ear  and  the  best  way 
for  us  to  accomplish  it  in  our  model,  is  to  im- 
merse the  forks  in  liquid  instead  of  air.  The 
greater  weight  of  the  liquid  will  be  more  effective 
in  moving  the  forks  and  the  viscosity  of  the 
liquid  will  be  effective  in  stopping  or  "damp- 
ing" their  motion  after  the  sound  has  ceased. 

Our  complete  apparatus  will  then  take  the 
form  shown  in  Fig.  3  where  as  before  we  have  a 


144 


Radio  Broadcast 


FIG.  2 

The  vibrations  of  one  tuning-fork  will  not  cause  a 
second  fork  to  vibrate,  and  thus  produce  a  musical 
sound,  unless  both  have  the  same  vibration  rate. 
However,  the  sounds  produced  by  a  piano  string, 
the  human  voice,  or  a  pipe  organ,  for  example, 
may  cause  vibrations  in  more  than  one  of  the 
forks,  since  such  sounds  are  made  up  of  many 
simple  tones,  some  of  them  being  the  same  as  those 
of  the  tuning-forks 

horn  (i)  which  gathers  up  and  concentrates 
the  sound  waves  at  the  small  end,  where  they 
cause  the  diaphragm  (2)  to  vibrate  in  unison. 
The  motion  of  this  diaphragm  will  then  have  to 
be  transferred  to  a  liquid  and  since  the  liquid 
will  be  very  much  heavier  and  harder  to  move 
than  the  air,  we  must  employ  a  leverage  be- 
tween the  diaphragm  and  the  liquid.  This 
leverage  we  have  shown  as  a  simple  lever  (3) 
attached  at  one  end  to  the  diaphragm  (2), 
pivoted  at  the  point  (4),  and  attached  at  the 
other  end  to  a  second  diaphragm  (5)  which 
encloses  the  liquid  in  the  chamber  (6).  Since 
liquids  are  practically  incompressible,  we  must 
employ  a  third  diaphragm  (7)  at  the  other  end 
of  the  chamber  so  that  the  liquid  can  move 
freely.  In  the  liquid  chamber  (6)  we  place  a 
large  number  of  tuning  forks,  each  of  a  differ- 
ent pitch  and  attach  to  each  of  these  forks  a 
carbon  microphone  (8-8  etc.),  each  with  its 
electrical  connections  to  a  battery,  transformer 
and  meter. 

Then  the  sound  entering  the  large  end  of  the 
horn  is  concentrated  at  the  small  end  and  causes 
the  diaphragm  (2)  to  vibrate.  The  motion 
is  then  transferred  by  the  lever  (3)  to  the  second 
diaphragm  (5)  and  thence  to  the  liquid  in  the 
chamber  (6).    Movement  of  the  liquid  causes 


the  forks  corresponding  to  the  various  simple 
components  of  the  sound  to  vibrate  in  propor- 
tion to  the  strength  of  the  components.  This 
motion  of  the  forks  affects  the  attached  micro- 
phones and"  thus  indicates  oh  the  meters '  (9-9, 
etc.)  We  thus  have  a  complete  apparatus  for 
detecting  the  presence  of  a  sound,  determining- 
its  loudness  and  analyzing  it  into  its  compon- 
ents and  thus  determining  its  character.  We 
have  shown  only  five  forks  in  the  model  but  it 
must  be  understood  that  it  would  be  necessary 
to  have  many  thousands  of  them.  The  lowest 
fork  would  have  a  pitch  corresponding  to  about 
32  vibrations  per  second  and  the  highest  from 
30,000  to  40,000  per  second. 

The  human  ear  is  constructed  in  principle 
almost  exactly  like  our  model  as  will  be  seen 
from  Fig.  4.  In  this  figure  we  have  the  exter- 
nal ear  ( 1 )  corresponding  to  the  horn  for  gather- 
ing up  the  sound  and  concentrating  it  on  the 
diaphragm  or  drumskin  (2).  The  leverage  be- 
tween the  drumskin  and  the  second  diaphragm 
in  the  liquid  chamber  is  obtained  by  a 
system  of  three  bones  (3)  named  from  their  ap- 
pearance, the  hammer,  the  anvil  and  the  stir- 
rup. This  particular  form  of  lever  is  employed 
to  prevent  any  unusual  shock  from  injuring  the 
delicate  apparatus  of  the  inner  ear,  since  these 
bones  are  arranged  so  that  they  slip  over  each 
other  at  their  joints  if  too  great  a  motion  is  im- 
parted to  them.  The  liquid  chamber  is  shown 
at  (6).  It  consists  of  a  bony  case  shaped  like  a 
snail  shell  and  named  from  its  appearance  the 
Cochlea.  The  end  of  the  lever  system  is  at- 
tached to  the  second  diaphragm  known  as  the 
Oval  Window  (4).  The  third  diaphragm  for 
the  purpose  of  allowing  freedom  of  motion  of 
the  liquid  shown  at  (5)  is  known  as  the  Round 
Window.  In  the  liquid  chamber  or  Cochlea 
(6)  are  located  the  thousands  of  vibrating  bodies 
of  various  shapes  and  sizes  which  take  the  place 
of  the  tuning  forks  in  our  model.  The  mi- 
crophones of  the  model  are  replaced  by  nerve 
terminals  attached  to  each  of  the  vibrating 
bodies,  each  terminal  being  connected  to  the 
brain  or  measuring  instrument  by  its  own  nerve 
fibre. 

This  short  description  cannot  do  justice  to 
the  wonderful  refinement  and  ingenuity  dis- 
played in  the  design  of  our  ears,  and  the  action 
of  some  of  the  mechanism  is  still  imperfectly 
understood.  We  know  very  little  about  the 
construction  of  the  vibrating  bodies,  particu- 
larly those  which  are  employed  to  respond  to 
the  lowest  frequencies.    These  vibrators  are  so 


The  Search  for  a  Telephone  as  Sensitive  as  the  Ear 


'45 


Vibrations  are  readily 
are  immersed  in  liquid 


FIG.  3 

started  and  quickly  "damped"  when  the  tuning-forks 
This  indicates  an  apparatus  for  detecting  the  presence 


of  a  sound,  and  determining  its  loudness  and  character.    The  human  ear  is  con- 
structed in  principle  in  a  similar  way 


small  that  they  are  not  visible  to  the  naked 
eye,  as  indeed  they  must  be  to  be  crowded  into 
the  small  space  available.  That  they  do  vibrate 
at  one  pitch  and  at  one  pitch  only  we  know. 
Neither  have  we  the  space  to  describe  the  ap- 
paratus for  equalizing  the  pressure  on  both 
sides  of  the  drumskin,  nor  the  means  for  tuning 
the  drum,  nor  a  host  of  other  devices  which  go 
to  make  up  the  complete  organism. 

This  description  is  sufficient,  however,  for  us 
to  gain  a  clear  idea  of  the  capabilities  and  limi- 
tations of  the  ear  which  must  be  taken  into 
account  in  the  design  of  radio  and  acoustical 
apparatus. 

The  most  significant  factor  in  the  construc- 
tion of  the  ear  is  the  completeness  of  the  an- 
alyzing apparatus.    We  should  expect  that  the 
question  of  distortion  in 
radio  telephones  would  be 
a  very  serious  one,  for  the 
ear  is  not  easily  fooled. 
This  subject  of  distortion 
has  been  completely  cov- 
ered in  a  previous  article* 
in  which  we  pointed  out 
most  of  the  things  which 
a  radio  telephone  must  do 
to  please  the  ear.  We 
shall,  therefore,  confi  ne 


ourselves  here  to  those 
things  which  the  system 
must  not  do. 

From  this  point  of  view, 
the  extreme  small  size  of 
the  parts  of  the  ear  is  sig- 
nificant as  will  be  seen 
from  Fig.  4  and  as  though 
Nature  had  not  gone  far 
enough  in  this  direction  to 
astonish  us,  she  tucked  into 
the  corners  the  apparatus 
by  which  we  balance  our- 
selves on  two  feet.  The 
smallness  of  the  fibre  which 
connect  the  vibrators  with 
the  brain  is  even  more  ex- 
traordinary. Some  idea  of 
their  size  may  be  gained 
from  the  fact  that  the  en- 
tire cable,.containing  thou- 
sands of  nerves,  is  less  than 
tV  inch  in  diameter. 
From  this  we  are  at  once  led  to  suspect  that 
one  of  the  weak  points  in  the  design  of  the  ear 
is  liability  to  fatigue  and  particularly  to  fatigue 
from  the  sounding  of  a  single  note.  The  case  is 
very  much  as  though,  in  our  model,  we  made 
the  wires  connecting  the  microphones  with  the 
measuring  instruments  very  small  so  that  if 
they  were  used  very  long  at  a  time  they  would 
heat  and  increase  their  resistance.  In  the  case 
of  the  auditory  nerves  exactly  this  happens, 
with  the  additional  psychological  factor  that 
when  a  nerve  is  fatigued,  we  become  nervous 
and  exasperated. 

This  point  is  readily  proved  from  your  own 
experience.  Almost  everybody  has  at  some 
time  in  his  or  her  life  been  irritated  to  the  point 
of  exasperation  by  children's  voices  and  this 


*"How  Your  Telephones 
Work,"  Radio  Broadcast  for 
January,  1923. 


The  mechanism  of  the  human  e*r 
apparatus:  "hammer,"  "anviV  and 

Window;  (6)  Cochlea 


FIG.  4 

(1)  External  ear;  (2)  drumskin;  (3)  leverage 
stirrup";  (4)  Oval  Window;  (5)  Round 


146 


Radio  Broadcast 


does  not  arise  from  any  lack  of  sympathy  with 
children.  It  is  due  to  the  fact  that  children 
have  not  yet  learned  the  knack  of  tonal  mo- 
dulation, so  that  they  talk  at  almost  a  constant 
pitch  and  this  is  more  particularly  true  when 
they  are  excited  or  interested  in  their  play. 
The  result  is  that  the  voice  sounds  have  all  to 
reach  the  brain  of  the  listener  over  a  very  small 
number  of  nerve  fibres  which  soon  become 
exhausted. 

It  is  true  that  not  all  monotonous  sounds  are 
irritating,  but  the  reasons  for  this  lie  in  the 
brain  rather  than  in  the  ear.  The  brain  has  the 
power  under  certain  circumstances 
to  shut  off  most  of  the  current  to 
a  given  set  of  nerve  fibres,  so  that 
they  are  not  fatigued  although  ex- 
cited for  long  periods.  This  con- 
trol exists,  however,  only  when  the 
sound  which  is  shut  off  is  different  in 
character  or  pitch  from  the  sounds 
to  which  we  are  trained  to  direct  at- 
tention. For  instance,  we  can 
easily  shut  out  the  noise  of  the  wheels  on  the 
rails  when  riding  in  a  railway  carriage.  On  the 
other  hand  we  are  trained  from  infancy  to  pay 
attention  to  the  sound  of  human  voices  and 
therefore  we  find  it  most  difficult  to  shut  out 
the  annoying  voices  of  children  at  play. 

It  is  also  very  difficult  for  the  brain  to  shut 
out  sounds  that  are  similar  to  other  sounds 
which  it  wishes  to  hear.  Have  you  ever 
watched  a  piano  tuner  search  all  over  the  room 
for  the  object  which  insists  on  vibrating  in 
resonance  with  a  certain  string  on  the  piano? 
The  reason  is  that  he  wishes  to  listen  to  the 
sounds  of  the  piano  and  he,  therefore,  finds  it 
impossible  to  shut  out  the  other  similar  sound. 

A  further  simple  experiment  to  prove  this 
point  is  to  have  someone  play  any  selection  on 
the  piano  and  while  this  is  in  progress  tap  a 
single  key  of  the  piano  lightly  and  continu- 
ously. It  will  be  impossible  to  direct  the.  at- 
tention away  from  this  insistant  note  and  it 
will  generally  be  found  that  the  result  is  so  an- 
noying to  everyone  within  hearing  that  the 
experimenter  will  be  forced  to  discontinue  his 
work  "under  pressure  of  public  opinion." 

A  long  series  of  tests  and  experiments  along 
the  above  line,  some  of  them  simple,  others  of  a 
more  technical  nature,  have  convinced  the 
writer  and  his  associates  that  this  liability  to 
local  fatigue  is  one  of  the  most  important  char- 
acteristics of  the  ear  from  the  viewpoint  <J  the 
designer  of  acoustical  apparatus.    This  con- 


clusion has  a  particularly  important  bearing 
on  the  design  of  the  acoustical  elements  of  a 
radio  telephone  system.  On  the  ordinary 
telephone,  we  never  listen  for  very  long  at  a 
time,  even  though  it  may  seem  an  eternity  when 
waiting  to  use  a  party  line,  whereas  in  radio 
broadcasting  we  may  listen  continuously  for 
hours.  For  an  illustration  of  the  way  in  which 
this  knowledge  of  the  characteristics  of  the  ear 
should  be  applied  in  the  radio  art,  we  turn  na- 
turally to  our  own  products,  telephone  receivers 
and  loud  speakers,  since  we  speak  there  with 
the  greatest  authority.  When  radio  broad- 
casting first  came  into  popularity, 
the  only  telephone  units  avail- 
able for  its  reception  were  those 
which  had  been  used  for  land  line 
telephone  and  wireless  telegraphy. 
Now  practically  all  of  these  tele- 
phones employed  a  magnetic  sys- 
tem which  varied  the  pull  on  an 
iron  diaphragm  in  accordance 
with  the  incoming  signal.  We 
tested  a  great  number  of  diaphragms  of  iron 
and  other  metals  and  found  that  all  of  them 
had  very  definite  natural  periods.  In  other 
words,  they  could  be  and  were  forced  by  the 
magnetic  system  to  vibrate  at  the  proper 
pitches.  However,  when  so  vibrating,  they 
also  vibrated  at  their  own  natural  pitch  which 
never  changed.  Here  we  have  the  ideal  condi- 
tion for  fatigue  of  the  ear. 

The  problem  was  then  to  devise  a  telephone 
diaphragm  which  was  "dead",  or  in  other  words, 
which  would  not  vibrate  freely  by  itself.  This 
problem  was  not  an  easy  one,  for  it  was  found 
very  early  that  all  of  the  metallic  materials  had 
strong  natural  periods  which  could  not  be  com- 
pletely killed  without  greatly  reducing  the 
sensitivity  of  the  phone.  However,  after  ex- 
perimenting with  a  great  variety  of  substances, 
a  non-metallic  diaphragm  material  was  found 
which  satisfied  the  requirements.  Receivers 
constructed  of  this  material  have  no  single-pitch 
clamor.  A  large  number  of  them  have  been 
placed  in  use  and  where  we  have  been  able  to 
obtain  the  opinions  of  the  users,  they  are  unan- 
imous that  these  instruments  may  be  used 
continuously  without  annoyance.  Results  in 
actual  service  by  a  large  number  of  users  are  the 
final  check  of  any  theory.  We  believe,  there- 
fore, that  we  have  proved  the  importance  of  the 
study  of  the  ear  and  havejustified  the  statement 
that  the  ear  is  the  most  important  of  radio  in- 
struments. 


Concerts  for  All  in  a  Veterans' 

Hospital 

By  J.  TOWNSEND  BRADLEY 


WHO  would  have  thought  that 
the  very  operators  that  pound- 
ed the  keys  off  Belle  Island 
north  to  the  White  Sea,  during 
the  War,  would  be  some  day 
turning  on  a  set  as  easily  as  a  phonograph  and 
getting  the  best  of  music  and  entertainment, 
leaning  back  in  an  easy  chair  and  just  listen- 
ing, without  the  dreaded  "  Dangerous  Area"  re- 
ports or  without  fear  of  missing  his  call?  What 
the  few  lines  that  follow  have  to  do  with,  is  the 
percentage  of  Navy  and  Army  men  that  didn't 
quite  get  through  and  who  have  been  in  Gov- 
ernment Hospitals  for  the  last  few  years.  To 
be  specific,  this  article  concerns  the  0.  S.  Veter- 
ans Hospital  No.  50,  which  along  with  its  Com- 
manding Officer,  is  well  known  and  a  favorite 
indeed  with  the  Veterans. 

The  majority  of  the  men  here  at  Prescott, 
Arizona,  do  not  know  much  about  radio,  but 
there  are  about  forty  loyal  radio  fans  and 
among  them  a  liberal  sprinkling  of  Army  and 
Navy  operators.  The  entire  group  are  ardent 
fans  and  aside  from  the  study  they  are  making 
of  radio,  they  furnish  quite  a  lot  of  amusement 
to  their  bunkies.  Nearly  every  ward  has  a 
radio  set  and  in  some  wards  two  may  be  found. 
The  result  is  that  the  heretofore  long  evenings 
are  now  passed  enjoyably  with  the  programs 
of  KHJ,  KFI,  and  KPO  as  well  as  many  other 
stations. 

The  receivers  used  vary  from  a  small  one-tube 
set  to  the  elaborate  five-tube  variety.  The 
majority  are  home-made,  but  quite  a  number  of 
the  men  prefer  to  buy  them  ready  made.  The 
general  practice  here  is  to  use  head  phones  be- 
cause loud  speakers  require  quite  a  volume  to 
operate  satisfactorily  and  then  are  likely  to 
wake  up  some  patient,  which  means  in  many 
instances  that  his  whole  night's  sleep  is  dis- 
turbed. The  ear  phones  are  generally  con- 
nected to  a  double  lamp  cord  that  runs  along 
the  moulding  and  down  to  the  receiver.  Thus 
in  case  a  patient  does  not  care  to  leave  his  bed 
and  go  down  to  his  buddy's  radio,  all  he  has  to 
do  is  to  lean  over  and  put  his  phones  on,  and 
in  comes  the  music. 


Wards  2,  10,  11  and  14  are  so  connected. 
The  Ward  14  radio  set  is  the  largest,  using 
a  Kennedy  Type  10 1  receiver  with  a  Type 
525  Audio  Amplifier  and  a  Wireless  Specialty 
Shop  two-stage  radio-frequency  attachment. 
The  antenna  and  ground  are  brought  to  one 
plug  which  can  be  used  in  such  a  way  as  to  use 
the  radio-frequency  amplifiers  or  not.  The 
same  connection  is  used  for  the  loop,  which 
has  a  small  variable  condenser  to  tune  it,  in 
addition  to  the  regular  clips. 


THE   5-TUBE   RECEIVER  IN   WARD  14 
The  veterans  at  the  Prescott,  Arizona,  hospital  enjoy  con- 
certs from  stations  1500  miles  away,  using  the  loop  an- 
tenna shown  in  the  picture 


148 


Radio  Broadcast 


TUNING-IN  WITH      HOME-MADE  STUFF 
V.  S.  Keggs  and  G.  B.  Gilchrist  listening  to  a  station  on  the  west  coast.  Head 
phones  are  generally  used  in  the  wards  so  that  the  sets  may  be  operated  without 
disturbing  one  s  neighbors,  especially  during  the  evening  hours 


Those  of  you  who  have  not  worked  with  radio 
in  this  part  of  the  country  do  not  know  what 
we  have  to  contend  with.  The  power  lines 
cause  a  great  deal  of  interference  and  reception 
is  usually  done  only  during  the  night.  The 
big  set  will  bring  in  the  signals  fairly  well, 
especially  on  cloudy  or  rainy  days.  We  al- 
ways can  get  arc  and  spark  and  as  several  of 
the  men  are  ex-Army  and  Navy  operators, 
they  copy  it  down  for  practice.  If  it's  press,  it 
is  hung  up  for  everyone  to  see. 

On  nights  when  the  static  comes  roaring  in 
we  connect  our  loop  and  a  few  stages  of  radio- 
frequency,  and  manage  to  do  remarkably  good 


work.  The  longest  distance 
covered  by  the  loop  so  far 
on  telephone  work  is  be- 
tween one  thousand  to  fif- 
teen hundred  miles.  On 
the  outdoor  antenna  we  get 
both  coasts,  Canada  and 
Mexico,  while  on  arc  and 
spark  signals  we  tune  in 
most  anything. 

The  loud  speaker,  when 
connected  and  placed  near 
a  window,  has  been  heard 
all  over  this  end  of  the 
Post  and  when  the  wind  is 
favorable,  has  been  heard 
as  far  away  as  Ward  2, 
which  is  at  least  three 
quarters  of  a  mile  dis- 
tant. You  city  people  must 
remember  that  our  nearest 
broadcasting  station,  other 
than  the  one  at  Phoenix,  Arizona,  is  about 
four  hundred  miles  away,  while  San  Francisco 
and  Portland  stations  are  at  a  much  greater 
distance  but  still  come  in  so  loud  that  the 
windows  quiver.  Our  favorite  stations  are 
KHJ,  KF1,  KPO,  and  the  Kansas  City  Star's 
Night  Hawks. 

Aside  from  amusing  the  gang  and  their  visi- 
tors, and  members  of  the  Staff  at  this  hospital, 
the  station  is  used  to  test  out  the  home-made 
sets  and  to  try  out  numerous  ideas  that  some 
of  the  men  have  put  into  practice.  The  place 
is  nearly  always  full  of  sets  and  parts  to  be 
tried  out. 


G 

here's  an  idea 

A  Marion,  Ohio,  reader  sends  us  the  accompanying  diagram  with  the  remark: 
"  Why  use  eight  switch  points  with  a  series-parallel  switch  when  six  will  do  and 
simplify  the  wiring?" 


Adventures  on  an  American  Yacht 

in  Mexico 

A  Few  Intimate  Glimpses  of  Actual  Happenings  in  the  Life  of  a  Commerical  Radio  Oper- 
ator.   Here  We  Find  the  Reason  for  so  Many  Young  Men  Entering  Radio  as  a  Career 

By  A.  HENRY 

Going  to  sea  is  what  radio  operating  usually  means,  and  true  stories  of  life,  as  an  operator  finds  it,  are  us- 
ually a  bit  salty.  The  author  of  this  article  has  operated  afloat  and  ashore.  He  is,  as  we  say  in  radio,  an  "old 
timer"  and  whether  you  sailed  the  seven  seas  when  he  did,  or  expect  to  sail,  or  are  sailing,  or  never  expect 
to  leave  your  home  town — life  as  it  is  lived  aboard  ship  should  be  interesting  to  you. 

This  is  the  fourth  of  a  series  of  true  stories  from  the  life  of  a  commercial  operator.  Next  month,  Mr. 
Henry  will  tell  about  his  trip  around  the  West  Indies  on  the  Duke  of  Sutherland's  yacht,  the  S.  Y.  Cantania. 
— The  Editor. 


A  LONG  toward  the  middle  of  April 

was  standing  with  a  group  of  opera- 
tors in  the  "  static  room  "  at  29  Cliff 
Street,  New  York,  swapping  stories 
and  waiting  for  something  to  hap- 
pen.   Now  and  again  the  buzzer  up  on  the  wall 
would  bark  out  the  signals  that  spelled  an 
operator's  name.    He  would  enter  the  superin- 
tendent's holy  of  holies  to  be  commended, 
transferred  or  fired,  and 
then  return  to  our  group. 

For  some  reason  or  other 
I  hated  that  buzzer — it  al- 
ways filled  me  with  un- 
pleasant forebodings  and 
each  time  it  spoke,  its 
menace  was  removed  only 
when  1  recognized  the  first 
two  or  three  letters  of  a 
name  not  my  own.  I  had 
been  in  the  static  room  for 
periods  of  an  hour  or  two 
on  the  sailing  and  arrival 
days  for  three  successive 
trips  now,  and  I  had  not 
been  called.  Just  as  I  was 
beginning  to  think  that 
my  fears  were  unfounded 
and  feel  almost  as  much 
at  home  as  some  of  the  older  members  of 
the  operating  profession — the  passengers  and 
crew  of  a  coastwise  liner — when  I  heard  my  last 
name  squawking  from  the  buzzer  and  recog- 
nized the  smooth  swing  of  the  "Super,"  who 
had  formerly  been  an  operator. 

Before  his  desk  I  felt  like  a  culprit  for  no 
other  reason  than  foolish  fear.  There  was 
nothing  I  could  think  of  to  be  worried  about 


I    but  I  couldn't  help  feeling  that  there  was 


something  in  the  wind.  Without  so  much  as 
looking  up  he  asked  me  if  1  knew  how  to  install, 
operate  and  keep  in  repair  a  2-KW  synchronous 
transmitter  and  type  E  tuner.  That  took  my 
breath  away  but  1  gaspingly  said  something 
about  being  able  to  do  it  if  I  could  look  one 
over  for  a  few  days.  Although  1  had  never 
actually  seen  one  1  had  read  up  on  it  quite  a 


s.  Y.    wakiva  1 
Anchored  in  the  Panuco  River,  a  few  miles  below  Tampico.    Steam  was  always 
up  and  the  yacht  kept  in  readiness  to  weigh  anchor  at  a  moment's  notice 


little  and  felt  that  it  was  but  necessary  to  re- 
duce my  book  knowledge  to  practice. 

"All  right,"  quoth  this  lord  high  executioner, 
"you  have  free  rein  in  the  school  and  in  the 
repair  department  and  a  week  to  learn  all  you 
can.  Then  I'm  going  to  send  you  out  to  do  the 
job  on  a  yacht  and  I  feel  that  you  will  do  it 
properly.    Will  you?" 

As  you  may  guess,  I  assured  him  that  1 


Radio  Broadcast 


150 


THE  NEW  RADIO  ROOM  WAS  FINISHED  AT  LAST 
And  I  transferred  the  2  K.  W.  outfit  to  its 
new  home.    There  was  hardly  room  to  get 
the  camera  in  when  the  job  was  done 


would.  For  the  moment,  I  forgot  that  I  had 
recently  fallen  in  love  with  a  young  lady  in 
Jacksonville  and  did  not  want  to  leave  my  pres- 
ent job,  but  there  was  no  backing  down  and 
the  mails  would  have  to  be  relied  upon  tem- 
porarily. 

So  I  spent  a  week  in  the  school  and  managed 
to  make  a  general  nuisance  of  myself  by  asking 
the  mechanics  too  many  questions  of  a  technical 
nature  which  they  dodged  by  becoming  angry. 
Upon  the  completion  of  my  training  I  was  pre- 
sented with  a  wavemeter,  which  in  those  days 
was  a  rare  instrument,  and  received  an  assign- 
ment as  junior  operator  on  a  ship  bound  for 
Nassau  and  Tampico.  The  yacht  to  which  1 
was  assigned  was  in  Tampico  and  the  plan 
was  for  me  to  work  my  way  down  and  for  the 
operator  there  to  work  his  way  back. 

After  a  voyage  during  which  there  was  only 
one  short  period  of  excitement  we  arrived  in 
Tampico.  The  excitement  occurred  some  time 
between  one  and  six  one  hot  morning  after  we 
had  rounded  Tortugas  and  were  in  the  Gulf 
of  Mexico.  The  radio  room  was  of  more  ample 
proportions  than  most  and  it  was  much  easier 
to  stand  night  watches  in  a  steamer  chair,  one 
of  which  was  easily  obtained  from  the  deck. 
On  the  particular  night  in  question  I  had  pro- 
cured the  chair  and  had  made  it  more  com- 
fortable by  the  addition  of  a  pillow  from  my 
bunk.  1  had  locked  the  wooden  screen  of  the 
radio  shack  on  the  inside,  making  it  impossible 
for  any  one  to  get  in  the  window.  Then  I 
closed  the  door  and  poked  the  front  end  of  my 
chair  against  it  to  keep  it  closed  as  there  was 
no  lock.    During  the  night  I  fell  asleep  and  was 


rather  rudely  awakened  by  having  my  chair 
pushed  along  the  floor  as  someone  opened  the 
door.  There  was  no  getting  out  of  it:  the  Cap- 
tain himself  caught  me  red-handed,  asleep  on 
watch.  He  delivered  a  lecture  to  which  1 
listened  very  attentively — and  when  he  de- 
parted my  repose  was  continued. 

In  Tampico  I  was  rather  surprised  to  find 
that  we  were  docked  along  a  great  wharf  with 
several  other  vessels  of  goodly  size.  It  was 
not  my  idea  of  Mexico  at  all.  1  had  expected 
to  find  a  few  adobe  huts  and  a  group  of  Mexi- 
cans stealing  each  other's  horses  and  scrapping 
over  a  beautiful  senorita.  Tampico,  in  many 
respects,  looked  like  innumerable  other  small 
cities. 

After  several  trips  to  and  from  the  yacht, 
which  was  anchored  some  three  miles  down  the 
river,  my  things  were  transferred  and  the  other 
operator  and  I  changed  abodes.  My  new  room 
was  a  dream.  As  there  were  no  guests  aboard, 
the  officers  were  using  the  guests'  quarters  and 
my  room,  which  adjoined  the  captain's,  was  a 
great  deal  more  sumptuous  than  any  of  those  I 
had  occupied  on  previous  assignments,  and 
when  I  forgot  about  my  huge  salary  of  thirty- 
five  dollars  a  month  (I  had  been  raised  five,  on 
accepting  this  foreign  assignment)  you  may 
be  sure  I  felt  very  much  of  a  lord. 

There  was  a  complete  crew  aboard  and  I  was 
surprised  to  learn  that  steam  was  always  up 
and  the  yacht  kept  in  readiness  to  weigh  an- 
chor and  depart  at  a  moment's  notice. 

Let  me  digress  for  a  moment  and  tell  you 
why  the  yacht  was  in  Mexico.  A  certain  oil 
company  had  holdings  outside  Tampico  and 
maintained  its  offices  in  the  city.  At  the  time 
we  are  considering,  just  about  ten  years  ago, 
there  was  quite  a  turmoil  under  way  in  dear 
old  Mexico,  and  Americans  were  looked  upon 
with  anything  but  favor.  American  oil  tank 
steamers,  taking  on  cargoes  at  Tampico,  could 
make  it  easy  for  those  operating  the  loading 
station  if  they  reported  their  approach  by  radio. 
This  was  particularly  true  in  view  of  the  un- 
reliable operation  of  the  telegraph  lines.  The 
Mexicans  would  not  hear  of  the  establishment 
of  a  radio  station  at  the  loading  point  so  the 
yacht  was  sent  down  and  anchored  a  few  feet 
from  shore.  A  telephone  line  was  run  out  to 
her  and  the  whole  arrangement  was  at  least  as 
good  as  a  land  station  would  have  been,  from 
an  operating  standpoint. 

In  addition,  two  swift  motor  boats  were 
provided  to  carry  the  employees  from  the  city 


Adventures  On  An  American  Yacht  in  Mexico 


151 


to  the  yacht  in  case  of  emergency.  For  a  time 
the  emergency  seemed  imminent.  The  United 
States  appreciated  the  situation  as  evidenced 
by  the  battleship  Connecticut  that  rode  at  an- 
chor off  the  bar  just  beyond  the  mouth  of  the 
Panuco  River. 

Part  of  my  duty  was  the  checking  up  of  in- 
coming oil  steamers  and  advising  the  local 
agent,  whose  office  was  only  a  short  distance 
from  the  point  where  we  swung  listlessly  amid 
the  muddy  water  that  swished  along  our  side 
as  it  passed  out  to  sea.  Time  and  again  the 
American  Consul  at  Tampico  would  call  me 
on  the  phone  and  request  me  to  relay  a  message 
to  the  Connecticut.  Unfortunately,  my  end  of 
the  conversation  could  not  be  kept  secret  from 
some  Mexican  carpenters  engaged  in  building  a 
new  radio  cabin  into  which  I  was  one  day  to 
transfer  the  installation.  These  gentlemen 
were  of  rebel  tendencies  and,  though  we  never 
gave  much  attention  to  them,  we  wouldn't 
have  trusted  them  with  a  plugged  nickel. 

Now  and  again  "  bum-boat "  men  would  come 
down  the  river  with  the  tide  and  offer  us  all 
manner  of  tropical  delicacies  such  as  mangoes, 
plantains,  pineapples,  alligator  pears  and  limes. 
As  a  rule  they  were  permitted  aboard  and  their 
smiles  and  bows  and  "Si  senor's"  and  "man- 
anas"  all  aided  them  in  removing  the  shekels 
from  our  jeans  without  resistance.  They  were 
not  the  blood  curdling  variety  of  Mexicans  at 
all. 

Except  for  having  to  sleep  under  a  mosquito 
bar  to  prevent  being  eaten  alive,  1  was  pretty 
well  satisfied  and  managed  to  become  very 
friendly  with  most  of  the  crew 
with  one  of  the  sailors  and 
a  mess-boy  peeved  the 
captain  more  than  a  little 
and  soon  won  his  whole- 
souled  ill-favor.  Among 
other  things,  he  arranged 
to  have  me  eat  at  the 
second  sitting  in  the  mess 
hall,  which  was  for  the 
quartermasters,  cooks, 
second  cooks,  mess  boys, 
etc.  Of  course  I  put  up 
a  howl  but  it  availed  me 
nothing. 

In  the  meantime,  I  had 
become  quite  friendly  with 
four  English  fellows  who 
operated  the  radio  outfits 
on  English  vessels  plying 


My  association 


between  Tampico  and  Galveston  and  Port 
Arthur.  One  of  them  agreed  to  purchase  some 
itch  powder  for  me;  which  he  did.  One  day  1 
was  seated  in  my  room  with  the  door  into  the 
hallway  wide  open.  The  mess  boy,  with  whom 
I  had  become  friendly  and  for  whose  friendship 
I  had  suffered  humiliation,  was  also  the  at- 
tendant who  took  care  of  the  captain's  room 
and  my  own.  As  I  sat  there  drawing,  he  came 
in  with  my  laundry  and  put  it  all  away  for  me. 
The  captain's  bundle,  he  had  dropped  in  the 
hallway  as  he  came  by.  With  a  wink  1  asked 
him  if  he  could  not  find  something  to  occupy 
him  on  deck  for  a  half  hour.  He  agreed  and 
departed.  The  captain's  laundry  was  moved 
into  my  room  and  the  door  closed.  It  was  then 
unpacked  one  piece  at  a  time  and  given  a  treat- 
merit  of  itch  powder  and  just  as  neatly  re- 
packed and  replaced  in  the  hallway.  Need  I 
describe  the  captain's  misery  for  the  next  two 
weeks? 

Inasmuch  as  it  was  necessary  for  a  certain 
number  of  us  to  be  on  board  at  night,  the  liberty 
launch  would  take  one  bunch  one  night  and  an- 
other the  next.  As  a  rule  I  was  satisfied  to  stay 
aboard  but  did  like  to  take  the  ride  up  with  the 
gang  and  come  back  to  the  yacht  to  copy  press 
from  Sayville  or  Key  West  or  Arlington.  Then 
I'd  go  back  when  the  launch  did  and  help  round 
up  the  drunkards.  Even  the  fellows  who  had 
no  use  for  me  when  they  were  sober  were  quite 
friendly  after  a  few  shots  of  cerve^a,  the  Mexi- 
can for  beer,  and  they  came  down  to  the  dock 
with  me  in  fine  style. 

There  is  one  such  rounding  up  expedition  that 
will  linger  long  in  my  memory.    The  fellows 


A  FOURTH  O    JULY  LIBERTY  PARTY 


152 


Radio  Broadcast 


had  been  paid  and  were  out  to  paint  the  town 
red.  We  pulled  in  as  usual — the  boatswain 
and  I — at  the  little  dock  some  two  blocks  from 
the  plaza  which  was  in  the  center  of  the  town. 
Just  one  block  from  our  dock  was  a  ram- 
shackle cantina  for  which  the  fellows  steered 
when  they  began  to  think  of  returning  home. 
Here  we  would  round  up  most  of  them,  put 
them  in  the  launch  and  go  back  for  the  rest. 
They  would  content  themselves  in  hilarious 
manner  or  in  slumber  according  to  their  par- 
ticular bent  until  we  returned.  As  a  rule  the 
sober  ones  would  join  our  scouting  party.  On 
the  night  I  have  in  mind,  we  rounded  up  all 
but  one  and  were  about  to  return  to  the  boat 
without  him  when,  on  a  corner  a  block  away, 
I  heard  him  wrangling  with  a  Mexican  police- 
man. From  the  names  the  officer  was  being 
called  1  knew  that  our  wandering  boy  had  been 
indulging  in  stronger  spirits  than  cerve^a.  I 
arrived,  after  a  sprint,  just  in  time  to  prevent 
the  cop's  lantern  from  being  kicked  across  the 
street.  The  cop  proved  a  decent  sort  and 
smiled  -as  I  persuaded  the  quartermaster  to 
come  along  with  me.  By  the  time  we  had  stag- 
gered to  the  cantina  on  the  corner,  the  others 
had  all  returned  to  the  launch  and  were  shout- 
ing for  us  to  hurry. 

Now  and  then  one  of  the  partly  sober  fellows 
in  the  launch  would  address  a  yell  to  my  charge 
which  the  latter  would  return  in  kind,  accentua- 
ting the  reply  with  a  wild  hat  waving  and 
gesticulation.    He  refused  point-blank  to  pass 


"I  EXPECTED  GUN   PLAY,  BUT  THERE  SEEMED  TO  BE  NO  GUNS 


the  cantina  without  "  jush  one  lil  drink,  Shpark, 
jush  one  more  lil  drink."  So  1  let  go  of  him  and 
in  he  went,  while  1  yelled  to  those  in  the  launch 
to  wait  for  us. 

I  went  into  the  cantina.  Two  Mexicans  were 
seated  opposite  each  other  at  a  small  table, 
their  sombrero  rims  touching  each  other  and 
two  glasses  of  some  sort  of  liquor  before  them. 
They  were  evidently  engrossed  in  the  discussion 
of  some  weighty  problem.  Before  I  could  get 
around  the  tables  that  intervened,  the  quarter- 
master had  poked  his  face  up  between  the  two, 
knocking  off  their  hats  as  he  did  so.  He  looked 
at  one,  then  the  other,  reached  for  their  glasses 
and  turned  them  upside  down  on  the  table.  1 
expected  gun  play,  but  there  seemed  to  be  no 
guns.  Instead,  there  was  one  of  those  sudden 
tropical  rains — of  glassware.  I  slid  into  a  1 
corner  and  turned  a  table  over  on  top  of  my- 
self. The  few  minutes  I  was  there  seemed  like 
a  life-time  and  just  as  the  free-for-all  was  about 
to  end,  the  crowd  from  the  launch,  attracted  by 
the  row,  put  in  their  appearance,  the  half- 
drunken  ones  yelling  like  fiends.  Again  the 
fray  was  on.  Then  1  heard  wild  blasts  from  a 
police  whistle  and  four  policemen  raced  in, 
lanterns  and  all.  In  a  jiffy  the  lanterns  had 
been  whisked  from  them  and  were  behaving 
like  comets  with  a  jag  on  as  they  were  thrown 
back  and  forth.  One  of  them  exploded  behind 
the  bar  and  covered  a  Mexican  with  burning  oil. 
In  his  fright  he  ran  around  like  a  wild  man  and 
finally  went  out  with  most  of  the  others  racing 
after  him.  That  ended  the 
scrap.  The  heads  in  our  party 
were  bleeding  as  we  made  our 
way  back  to  the  yacht,  arriv- 
ing some  three  hours  late. 

After  two  month's  carpen- 
try work  on  a  six-by-six  ra- 
dio shack  that  could  have 
been  built  in  this  country  in 
a  week,  the  palace  into  which 
I  was  to  move  the  radio  set 
was  completed.  Before  the 
set  was  installed,  the  captain 
had  a  trap  door  cut  in  the 
floor  which  opened  into  the 
centre  of  the  library  below. 

"  You  never  can  tell  when 
you  may  need  it,"  he  ex- 
plained. "These  'spigs'  are 
not  much  afraid  of  the  Amer- 
ican flag  that  flies  from  our 
stern." 


Adventures  on  an  American  Yacht  in  Mexico 


153 


The  trap  door  took  another  two  days,  two  of 
the  sailors  doing  the  job.  It  was  made  with 
springs  and  a  spring  lock.  We  had  a  bully  time 
throwing  the  latch  and  dropping  through  to 
the  deck  below,  for  practice. 

Finally  1  transferred  the  radio  outfit  and 
spent  the  better  part  of  three  days  getting  it 
tuned  up.  Then  as  the  oil  tankers  would  arrive 
or  depart  1  would  carry  on  tests  with  them  and 
got  the  outfit  working  in  fine  style.  By  making 
certain  changes  in  the  antenna,  it  was  possible 
to  improve  both  the  receiving  and  transmitting 
range.  I  could  count  on  the  old  type  E  tuner 
and  carborundum  detector  to  pull  in  press  from 
Arlington  nearly  every  night.  That  meant  late 
working  and  there  were  many  nights,  especially 
when  it  was  very  warm,  that  I'd  fall  into  the 
bunk  they  had  built  in  the  room,  read  a  few 
chapters  of  some  book,  and  go  to  sleep. 

On  one  such  night  I  was  almost  asleep  when  a 
commotion  on  deck  startled  me.  There  was  a 
shuffling  of  feet  and  I  was  about  to  go  out  and 
see  what  it  was  all  about,  when  the  mess  boy 
yelled :  "  Sparks !  Sparks !  For  God's  sake,  beat 
it!  Two  'spigs' — "I  waited  for  no  more,  but 
dropped  through  the  trap  door,  slamming  it 
shut  as  I  went  through.  Then  I  raced  along 
the  lower  deck  and  down  to  the  engine  room. 
As  I  went,  I  pulled  off  my  outside  shirt  and 
smeared  my  face  with  grease  grabbed  from 
some  of  the  running  gear.  The  chief  engineer 
happened  to  be  in  the  engine  room  and  I  told 
him  what  the  trouble  was.  "  Here, "  he  said, 
as  he  passed  a  pair  of  begrimed  overalls  to  me, 
"  jump  into  these  and  be  an  engineer  for  a  while. 
I'll  go  and  help  Andy  get  rid  of  the  'spigs'." 
(Andy  was  the  mess-boy).  As  he  raced  up  on 
deck,  I  thought  of  a  post  card  received  from  my 
dad  a  few  days  before,  bearing  the  cheering  mes- 
sage, "  Don't  Worry."  I  struggled  into  the 
overalls,  smeared  myself  with  more  grease  and 
went  up  to  the  scene  of  the  melee. 

By  the  time  I  got  there  the  Mexicans  were 
outnumbered  and  were  jabbering  in  three  parts 
Mexican  and  one  English  about  wanting  only 
to  kill  the  "telegraphista"  who  they  said  was 
giving  information  of  their  activities  to  over- 
come the  existing  ruler  of  the  land.  When  I 
appeared  they  paid  no  more  attention  to  me 
than  any  of  the  others.  Eventually  they  were 
calmed  down,  assured  that  we  bore  them  no 


malice  and  were  lowered  into  their  boat.  Then 
they  drifted  away  with  the  tide  and  were  soon 
nothing  but  a  dark  spot  on  the  silver-crested 
Panuco. 


Perhaps  the  firemen  and  sailors  were  treated 
to  an  even  greater  surprise  than  I,  for  the  first 
mate,  a  huge  down-easter  who  could  not  talk 
without  swearing  and  boasting  of  his  acts  of 
prowess  in  the  good  old  sailing-ship  days,  was 
awakened  by  the  row  on  deck.  As  he  rushed 
past  the  galley  to  gather  his  clan  from  the 
fo'c's'le  the  night  watchman  yelled  something 
about  being  attacked  by  Mexicans.  As  the 
mate  reached  the  fo'c's'le  companionway,  he 
saw  a  movement  in  the  trees  along  the  shore, 
became  frightened,  made  for  the  saluting  can- 
non and  shot  it  off. 

The  cannon  was  on  the  deck  just  above  the 
crew's  sleeping  quarters  and  some  of  them 
rushed  up  in  time  to  prevent  the  mate  shooting 
away  any  more  of  the  forward  canopy  and  rail 
in  an  attempt  to  scare  off  shadows  caused  by 
the  moonlight  among  the  trees.  A  very  pleas- 
ant time  was  had  by  all. 


Choosing  Your  Regenerative  Circuit 

The  Advantages  and  Disadvantages  of  the  Single 
Circuit  and  Three-Circuit  Regenerative  Receivers 

By  PAUL  F.  GODLEY 

For  some  time,  Radio  Broadcast  has  told  its  readers  of  the  shortcomings  of  the  popular  single- 
circuit  regenerative  receiver.  In  doing  so,  it  has  not  lost  sight  of  the  advantages  of  such  outfits.  The 
belief  exists  very  strongly  in  many  quarters,  and  there  seems  to  be  a  great  deal  of  logic  behind  it,  that 
the  benefits  of  this  type  of  receiver  are  outweighed  by  its  disadvantages.  Many  arguments  for  and 
against  it  have  been  advanced  and  one  dissertation  in  particular,  under  the  name  of  a  man  who  should 
know  better,  is  full  of  misleading  statements,  based  upon  a  theory  he  would  like  to  have  the  public 
believe. 

Paul  F.  Godley,  the  author  of  this  article,  is  vouched  for  by  all  who  know  him.  His  remarks  con- 
cerning the  two  types  of  regenerative  receivers  are  clearly  put  and  to  the  point.  If  the  exponents  of  the 
single-circuit  receiver  can  produce  as  sound  a  case,  we  should  like  to  publish  it. — The  Editor. 


WHAT  type  of 
receivershall  1  buildorbuy?" 
is  a  question  which  is  asked 
again  and  again.  It  seems 
that  many  of  those  who 
have  had  experience  are  unable  to  answer 
this  question  satisfactorily  even  for  them- 
selves. The  intent  of  this  discussion  may  best 
be  expressed  by  the  belief  that  an  understand- 
ing of  the  simple  action  of  a  regenerative  re- 
ceiver will  enable  any  one  to  clear  up  the  ques- 
tion for  himself. 

In  general,  there  are  two  classes  of  re- 
generative receivers,  and  their  exponents 
claim  certain  advantages  for  each.  They 


ANT.  TUNING 
C0ND.\ 


ANT.  CIRCUIT 
INDUCTANCE 


ANTENNA 
CAPACITY 


FIG.  I 


A  typical  single-circuit  arrangement,  with  the 
tube  connected  directly  to  the  antenna  circuit 


are  known  as:  single-circuit  regenerative  re- 
ceivers (Fig.  i),  and  three-circuit  regenerative 
receivers  (Fig.  2).  Both  have  marked  ad- 
vantages over  many  other  methods  of  re- 
ception. 

Because  of  its  simplicity,  the  larger  manu- 
facturers have  chosen  the  single-circuit  re- 
ceiver for  their  sales  campaigns.  By  utiliz- 
ing this  simplest  type,  the  greatest  number 
of  people  may  be  brought  to  the  use  of  radio 
in  the  shortest  time.  It  is  interesting  to  note 
in  this  connection  that  in  England,  due  to  a 
quite  general  use  of  the  single-circuit  type, 
laws  designed  to  prevent  the  use  of  all  types 
of  regenerative  receivers,  have  been  enacted. 

In  the  opinion  of  the 
writer,  the  British  law  is  as 
far  fetched  as,  perhaps, 
ours  is  lax. 

The  three-circuit  regen- 
erative receiver  is  manu- 
factured at  the  present 
time  by  several  of  the 
smaller  companies  who 
have  consistently  clung  to 
this  type  because  of  its 
marked  selectivity  and 
sensitivity,  in  the  belief 
that  the  gradual  education 
of  the  public  to  what  is 
best  will  eventually  lead 
to  a  preponderance  in 
number  of  the  three-circuit 
receiver. 

The  essential  difference 
between  the  two  types 


Choosing  Your  Regenerative  Circuit 


155 


may  be  gathered  by  com- 
parison of  Figs.  1  and  2.  It 
will  be  noted  that  in  the 
circuit  of  Fig.  1 ,  the  vacuum 
tube  is  coupled  directly  to 
the  antenna  circuit,  while  in 
Fig.  2,  the  vacuum-tube  cir- 
cuits are  coupled  to  the 
antenna  circuit  through  in- 
terlinkage  of  the  magnetic 
fields  of  the  two  coils,  L  and 
L1.  In  the  single-circuit  re- 
ceiver the  coupling  between 
the  vacuum-tube  circuits 
and  the  antenna  is  100%, 
in  the  three-circuit  receiver 
that  value  of  coupling  which 
works  out  to  greatest  ad- 
vantage, both  with  regard  to 
sensitivity  and  selectivity,  is 
usually  of  the  order  of  1%. 

Notwithstanding  the  size 
of  the  United  States,  consid- 
erable annoyance  is  caused 
by  the  energy  radiated  from  regenerative  re- 
ceivers. They  actually  may  be  so  adjusted 
as  to  operate  as  transmitters.  And  while  all 
types  of  regenerative  receivers  may  give  rise 
to  interfering  energy  radiation  (unless  direct 
steps  have  been  taken  to  prevent  this)  the 
use  of  regenerative  receivers  in  which  the 
vacuum-tube  circuits  are  very  loosely  coupled 
to  the  antenna  would  go  so  far  toward  the 
abatement  of  this  annoyance  that  the  question 
would  never  in  seriousness  be  raised  as  to 
whether  or  not  we,  in  this  country,  should 
legislate  against  these  "transmitting  re- 
ceivers." 

WHY    AN   OSCILLATING   RECEIVER  TRANSMITS 

BUT,"  you  ask,  "how  does  this  trans- 
mission by  a  receiver  come  about?" 
Also,  "  If  a  smaller  amount  of  energy  is  trans- 
ferred from  the  generating  circuits  to  the 
antenna,  would  not  the  same  smaller  amount 
of  energy  be  transferred  from  the  antenna  to 
the  generating  circuits  in  the  case  of  an  in- 
coming signal?"  In  the  answer  to  these 
questions  lies  an  understanding  of  the  re- 
generative principle.  Those  who  would  choose 
intelligently  between  receivers  of  various 
types  would  do  well  to  study  this  simple 
action. 

The  telephone  has  been  with  us  now  for  so 
many  years  that  it  has  become  a  household 


ANT.  TUNING  CONO. 
/ 


FIG,  2 

The  three-circuit  arrangement.  The  principal  point  of  difference  be- 
tween this  and  the  hook-up  shown  in  Fig.  1  is  that  the  vacuum-tube 
circuits  are  inductively,  not  conductively,  coupled  to  the  antenna  circuit 


commonplace.  Scarcely  is  there  a  person  who 
has  not  endeavored  to  play  the  practical 
joke  which  may  be  perpetrated  by  placing 
the  telephone  receiver  against  the  telephone 
mouthpiece.  When  this  is  done,  a  loud 
squawking  or  squealing  results,  to  the  great 
discomfiture  of  the  "party"  on  the  other 
end.  The  "squawking"  arises  due  to  regen- 
eration— to  a  "feed-back"  of  energy  as  fol- 
lows: when  the  receiver,  Fig.  3,  is  placed 
against  the  mouthpiece,  the  slight  jarring  of 
the  mouthpiece  disturbs  the  carbon  granules 
of  the  microphone  behind  it;  disturbance  of 
the  granules  changes  the  resistance  of  the 
microphone,  which  results  in  a  change  of  the 
flow  of  current  through  it ;  the  changed  current 
brings  about  a  change  of  the  magnetic  lines 
of  force  which  permeate  the  induction  coil; 
the  sudden  rise  and  fall  of  the  magnetic  lines 
of  force  create  within  the  secondary  winding 
of  the  induction  coil,  a  fluctuating  current 
which  energizes  both  the  telephone  line  wire 
and  the  telephone  receiver.  If  this  cycle  of 
changes  took  place  but  once,  there  would  be 
heard  in  the  telephone  receiver  one  very  short 
click.  But,  so  long  as  the  receiver  is  held  to 
the  microphone,  the  cycle  of  changes  occurs 
over  and  over  again.  The  click  in  the  re- 
ceiver serves  to  disturb  the  granules  in  the  mi- 
crophone a  second  time,  and  so  on  and  on. 
The  rate  at  which  these  disturbances  occur 


1 56 


Radio  Broadcast 


FIG.  3 

Illustrating  the  principle  of  "feed-back"  or  regeneration 


depends  upon  the  electrical  length  of  the  cir- 
cuit over  which  the  pulsations  travel,  and  the 
distance  at  which  the  receiver  is  held  from  the 
microphone.  This  rate  is  usually  of  such 
order  as  to  result  in  a  very  shrill,  screeching 
noise. 

Regeneration  in  the  vacuum-tube  circuits 
is  very  similar  indeed  to  that  outlined  above. 
The  grid  of  the  vacuum  tube  may  be  likened 
to  the  telephone  receiver;  the  electron-filled 
vacuum  between  the  filament  and  the  plate, 
to  the  carbon-granule  microphone.  Current 
pulses  received  by  the  circuit  to  which  the 
grid  is  attached  are  passed  to  the  grid  where 
they  effect  a  very  large  change  in  the  flow  of 
the  electrons  between  the  filament  and  the 
plate.  As  the  charges  received  by  the  grid 
alternate  in  polarity  from  positive  to  nega- 
tive, the  flow  of  electrons  between  filament  to 
the  plate  alternates  in  magnitude.  The  cur- 
rent fluctuations  in  the  output  circuit  are  fed 
back  to  the  grid  (input)  circuit  of  the  tube. 
Thus,  the  grid  is  charged  a  second  time  and 
a  second  fluctuation  of  current  in  the  output 
circuit  results.  The  magnitude  of  the  cur- 
rent pulse  in  the  output  circuit  is  always 
greater  than  that  of  the  pulse  which  gave  rise 
to  it,  for  the  reason  that  the  three-element 
vacuum  tube  is  an  amplifier.  Thus  the  feed- 
ing back  of  the  enlarged  impulses  to  the  input 
circuit  will  result  in  a  still  larger  fluctuation  in 
the  output  circuit  during  the  second  cycle,  and 
this  enlarging  action  will  continue  until  the 
resistive  forces  in  the  circuit  are  completely 
offset. 

THE  HOW  AND  WHY  OF  REGENERATION 

LET  us  apply  this  action  in  the  circuits  of 
Fig.  i.  The  condenser  formed  by  the 
antenna  and  earth,  the  inductance  and  the 
variable  condenser  across  which  the  antenna 
(condenser)  is  shunted,  the  connecting  leads, 
the  by-pass  condenser  and  variometer,  or 
"tickler,"  in  the  output  circuit  of  the  vacuum 
tube,  all  possess  inherent  qualities  which  tend 


to  resist  the  flow  of  any  kind  of  electrical 
oscillation  within  or  through  them.  If  a  bit 
of  energy  in  the  form  of  an  electrical  current 
is  created  in  the  antenna  system,  it  rapidly 
spends  itself  in  overcoming  this  resistive 
force  and,  by  the  time  it  has  reached  the  point 
where  we  expect  it  to  perform  its  useful 
function,  serious  inroads  have  been  made 
upon  it.  The  extent  to  which  it  is  dissipated 
depends,  of  course,  upon  the  amount  of  re- 
sistance which  it  is  called  upon  to  overcome. 
But  let  us  assume  that  the  circuit  of  our  dia- 
gram (Fig.  i )  is  average  in  every  respect,  and 
that  the  resistance  encountered  is  not  too 
great  to  defeat  effective  operation.  We  have 
insured  proper  connections  in  our  circuit  and 
lighted  the  filament  of  the  vacuum  tube. 
Immediately  this  is  done,  current  supplied  by 
the  B  battery  starts  an  electron  flow  across  the 
vacuum  from  the  filament  to  the  plate. 

By  controlling  the  electrical  length  of  the 
output  circuit  (varying  the  inductance  and 
capacity  in  it)  let  us  "time"  or  tune  the 
journeys  of  the  current  pulses  in  it  and  trans- 
fer a  portion  of  the  output  circuit  energy, 
at  the  proper  time,  back  into  the  grid  or  input 
circuit.  If  the  timing  (tuning)  has  been  prop- 
erly done,  the  charge  upon  the  grid  will  be 
reenforced  by  that  heavier  charge  taken  out 
of  the  plate  circuit. 

In  the  ordinary  regenerative  vacuum-tube 
receiver,  the  electron  discharge  of  the  tube 
and  the  power  stored  up  in  the  batteries  may 
be  called  upon  to  an  extent  sufficient  to  gen- 
erate oscillatory  energy  at  a  very  rapid  rate. 
An  antenna  of  two  or  three  hundred  ohms — 
and  this  is  quite  a  high  resistance — will  not 
serve  to  prevent  this  vacuum  tube  action  from 
compensating  for  the  resistance  of  the  circuits. 
It  is  for  this  reason  that  the  regenerative  cir- 
cuit has  proven  so  effective  as  a  radio  receiver. 
Theoretically,  no  matter  how  inefficient  may 
be  the  units  which  comprise  the  circuit,  the 
vacuum  tube,  by  regeneration,  makes  up  for 
inefficiencies,  but  practically  efficient  units  are 
of  as  great  advantage  in  the  regenerative 
receiver  as  in  any  other  type,  for,  it  will  be 
remembered,  the  vacuum  tube  does  not  com- 
pensate for  circuit  inefficiencies  when  it  is 
not  carefully  adjusted  to  a  point  just  below 
oscillation  or  when  it  is  not  actually  oscillat- 
ing. The  value  of  efficient  units,  therefore, 
is  apparent  in  the  preliminary  adjustments 
necessary  when  tuning  in  a  station,  when  it 
is  impossible  to  hold  all  circuits  at  this  critical 


Choosing  Your  Regenerative  Circuit 


'57 


point.  The  currents  upon 
the  grid  are  those  which 
control  the  action  out- 
lined. The  character  of 
the  oscillatory  currents  in 
the  whole  circuit  are  de- 
termined by  the  form  or 
character  of  those  which 
reach  the  grid  from  the  an- 
tenna. The  circuit  which 
we  have  been  treating 
above  is  that  of  the  single- 
circuit  receiver.  When  the 
currents  in  the  grid  cir- 
cuit of  this  receiver  have 
been  reenforced  by  the 
feed-back  of  energy,  the 
currents  in  the  antenna 
circuit  have  also  been  re- 
enforced,  for  grid  and 
antenna  circuits  are  so 
closely  coupled  by  the  in- 
ductance and  capacity 
common  to  both  of  them, 
that  they  act  as  one. 

WHERE  THE  THREE- 
CIRCUIT  RECEIVER  DIFFERS 

IN  THE  three-circuit  re- 
ceiver of  Fig.  2,  this  is 
not  true.  For  example, 
let  us  assume  that  the 
vacuum-tube  circuits  are 
quiescent,  and  that  a  sig- 
nal pulse  arriving  upon 
the  antenna  induces  a  like  signal  current  in  the 
secondary  circuit  of  Fig.  2.  The  charge  ar- 
riving upon  the  grid  as  the  result  of  this  in- 
ductive action  will  be  slightly  smaller  than 
that  charge  arriving  upon  the  grid  had  the 
grid  circuit  and  antenna  circuit  been  very 
closely  coupled,  depending  upon  the  excellence 
of  design  of  the  receiver  circuits.  But,  this 
slight  loss,  along  with  other  losses  of  the  cir- 
cuits, may  be,  and  is,  fully  compensated  for 
by  regenerative  action  and  the  signal  built 
up  and  up  in  the  system  until  its  value  is 
equal  to  or  greater  than  that  of  the  energy 
placed  in  the  antenna  by  the  passing  electric 
wave.  As  the  regenerative  energies  in  the 
grid  circuit  grow  larger  and  larger,  their  ten- 
dency toward  control  of  their  own  destiny 
becomes  greater  and  greater.  Conversely, 
their  dependence  upon  the  form  or  nature  of 
those  oscillations  in  the  antenna  circuit  be- 


KEEPING  IN  PRACTICE 
Paul  Godley  taking  copy  from  the  New  Brunswick, 
N.  J.  transatlantic  station  at  50  words  a  minute 


comes  less  and  less,  and  this  divergence  may 
increase  until  they  are,  in  effect,  unguided  by 
the  form  of  the  oscillations  in  the  antenna  cir- 
cuit. Therefore,  if  coupling  is  too  loose,  dis- 
tortion will  set  in.  When  it  is  too  tight,  it  is 
impossible  to  secure  the  maximum  benefits  of 
regenerative  amplification.  Between  the  two 
lies  the  ideal — some  arrangement  which  pro- 
vides control  over  the  coupling  between  the 
antenna  and  grid  circuits  and  which  makes  it 
possible  for  us  to  reach  this  ideal. 

In  the  case  of  the  three-circuit  receiver,  the 
regenerating  circuits  are  working  upon  a 
slightly  weaker  initial  signal  and  when  too 
loosely  coupled  are  prone  to  distortion,  re- 
sulting from  lack  of  guidance.  In  the  single- 
circuit  receiver  the  guiding  forces  are  100% 
present  and  there  are,  in  addition,  many  other 
stray  forces — forces  existing  in  the  antenna 
due  to  shocks  which  it  receives  from  powerful 


1 58 


Radio  Broadcast 


"off-wavelength"  oscillations  which  pass 
through  it.  These  forces  may  have  been 
caused  by  powerful  amateur  or  ship  or  naval 
stations,  by  discharges  of  faulty  electric  lines, 
telephone  circuits,  "buzzer"  circuits,  and 
what  not.  From  the  foregoing  it  may  be 
understood  why  the  single-circuit  receiver  is 
subject  to  these  disturbances  and  it  may  also 
be  understood  why  the  three-circuit  receiver, 
comparatively,  is  free  from  them. 

Where  the  regenerative  circuits  are  to  a 
large  degree  freed  from  external  influence, 
they  may  be  very  gradually  adjusted  toward 
those  settings  where  maximum  regeneration 
without  oscillation  (and  therefore  maximum 
undistorted  signal)  is  had.  Let  us  suppose 
this  freedom  is  lacking.  When  the  adjust- 
ments are  approaching  a  very  critical  setting, 
if  some  disturbing  external  influence  suddenly 
throws  into  the  circuit  a  powerful  pulse,  the 
pulse  is  repeated  through  to  the  output  circuit 
and  in  its  greatly  enlarged  form,  back  into 
the  grid  circuit.  Thus  the  circuits  are  sud- 
denly thrown  into  oscillation  and  the  signal 
distorted.  Where  the  antenna  circuit  is  di- 
rectly coupled  to  the  grid  circuit,  this  effect 
is  continually  taking  place.  It  makes  it  im- 
possible to  secure  a  maximum  of  undistorted 
regeneration,  so  that,  whereas  in  the  case  of 
the  direct-coupled  circuit  the  initial  signal  is 
slightly  larger,  it  never  can  be  so  greatly  en- 
larged due  to  regenerative  action  as  in  the 
coupled  circuits. 

Although  the  key  to  the  ideal  case  for 
the  regenerative  receiver  lies  in  the  con- 
trol of  the  coupling  between  antenna  and 
vacuum-tube  circuits,  the  idea  must  not  be 
had  that  a  continual  adjustment  and  read- 


justment of  this  coupling  value  is  necessary. 
In  a  well  designed  receiver  it  is  not.  For  a 
given  band  of  wavelengths,  say,  360  to  400, 
and  a  given  antenna,  the  value  of  this  coupling 
may  be  chosen  and  allowed  to  rest.  This 
value  varies  greatly  for  different  antennas, 
depending  upon  their  resistance,  and  it  may 
vary  slightly  for  fairly  large  changes  in  wave- 
length, for  the  resistance  of  any  circuit  will 
change  with  wavelength. 

The  observing  reader  will  have  foreseen  the 
result  of  the  coupled-circuit  receiver  with  re- 
gard to  what  is  known  as  selectivity — free- 
dom from  undesired  signals.  And,  too,  he 
will  have  noted  that  in  so  far  as  manipulation 
of  the  circuits  within  a  given  band  of  wave- 
lengths is  concerned,  he  has  three  variable 
controls  to  deal  with  instead  of  two.  In  the 
single-circuit  receiver  there  is  the  wavelength 
dial — the  dial  which  governs  the  wavelength 
of  the  antenna-grid  circuit  and  the  regen- 
erative control.  In  the  three-circuit  receiver 
there  are  the  wavelength  dials  of  the  grid 
circuit  and  the  dial  which  serves  to  keep 
the  antenna  circuit  in  resonance  with  the 
grid  circuit,  and  the  regenerative  control. 
To  be  sure,  there  is  no  technique  required  to 
operate  the  one,  while  a  certain  amount  of 
technique  is  required  to  operate  the  other; 
but  who  does  not  take  pride  in  the  mastery  of 
a  thing,  and  who  is  there  that  enjoys  the  radio 
concert  or  the  conversation  with  a  friend  half 
a  continent  away,  who  would  not  give  a  few 
hours  of  application  to  technique  in  order 
that  his  pleasure  may  be  increased  by  free- 
dom from  disturbance,  and  by  the  knowl- 
edge that  he  is  causing  a  minimum  of  inter- 
ference to  others? 


International  Law  and  the  Sea-Goin; 

Telegrapher 


By  CLAUDE  CATHCART  LEVIN 

Associate  Editor  of  The  A  merican  Officer 


UNDER  the  provisions  of  The 
London  International  Radio-tele- 
graphic Convention  of  191 2,  the 
nations  signatory  thereto  bind 
themselves  to  take  or  propose  to 
their  respective  legislatures  the  necessary 
measures  for  insuring 
the  carrying  out  of 
the  Convention's  reg- 
ulations. 

Thus  the  radio  laws 
and  regulations  of  the 
U.  S.  are  fundamen- 
tally those  of  the  Lon- 
don Convention,  as 
are  also  those  of  the 
other  signatories. 

Great  Britain,  how- 
ever, realizing  the 
inadequacy  of  laws 
framed  in  191 2  as  ap- 
plied to  modern  com- 
munication, has  gone 
much  farther  and  has 
passed  legislation  af- 
fecting radio  which 
stands  as  a  model 
and  which  will  un- 
doubtedly have  great 

influence  in  the  next  convention  whenever  it 
is  held. 

Under  British  law,  ships  are  divided  into 
three  classifications: 

1.  Those  carrying  200  or  more  persons  and  not 
engaged  in  British  coastwise  trade. 

2.  Ships  not  engaged  in  British  coastwise  trade 
carrying  50  but  less  than  200  persons,  and  ships  en- 
gaged in  British  coastwise  trade  carrying  50  persons 
or  more. 

3.  Ships  carrying  less  than  50  persons. 

The  rules  in  general  require  that  a  vessel  of 
the  first  class  shall  carry  three  licensed  radio 
operators;  that  a  vessel  of  the  second  class  shall 
carry  one  certificated  operator  and  two  certifi- 
cated watchers,  and  that  a  vessel  of  the  third 


The  Radio  Man  at  Sea 

The  best  of  laws  become  obsolete,  and  we 
find  it  hard  to  reconcile  our  present  activities 
in  radio  with  the  law  of  1912.  From  the  point 
of  view  of  the  operator,  that  law  is  far  from 
satisfactory,  and  it  is  true  that  although  con- 
ditions at  sea  are  not  entirely  despicable — as 
some  of  the  more  radical  unionists  would  have 
us  believe — there  is  plenty  of  room  for  im- 
provement. 

The  author  has  been  in  close  touch  with  the 
matter  and  has  served  as  President  of  the 
United  Radio  Telegraphers'  Association.  He 
is  Associate  Editor  of  The  American  Officer, 
a  marine  publication,  and  is  conversant  with 
marine  radio  affairs.  Radio  Broadcast 
would  like  to  receive  articles  on  the  subjects 
discussed  in  this  article  from  other  men  who 
are  helping  to  make  life  sale  at  sea. 

— The  Editor. 


class  shall  carry  one  certificated  operator.  The 
"certificate"  corresponds  to  the  "license  "issued 
to  radio  operators  by  the  American  Government. 

The  provisions  of  the  act  apply  to  all  vessels, 
foreign  as  well  as  British,  of  1,600  gross  tons 
and  over  touching  at  British  ports,  and  are 

now  in  force  through- 
out the  United  King- 
dom, Australia,  and 
India. 

These  provisions  are 
far  ahead  of  those  of 
America  and  the  other 
nations  which  have 
not  passed  similar  leg- 
islation and  which  are 
operating  under  their 
own  laws  based  upon 
those  of  the  Conven- 


tion. 

Under  the  provi- 
sions of  the  Conven- 
tion, ship  stations  in 
constant  service  are 
required  to  have  on 
board  at  least  two 
certificated  radio  op- 
erators, who  will  main- 
tain constant  service 
(this  on  vessels  carrying  50  or  more  persons 
and  traveling  certain  distances).  On  ships 
carrying  less  than  50  persons,  radio  is  not  com- 
pulsory. 

The  application  of  the  British  law  to  vessels 
of  all  other  nations  was  quickly  felt.  Italy 
soon  passed  similar  legislation,  with  the  result 
that  the  situation  there  is  practically  the  same 
as  in  the  United  Kingdom,  except  that  they 
have  no  watchers.  (A  watcher  is  a  person 
certified  to  be  able  to  receive  a  distress  signal 
at  a  slow  rate  of  speed  and  is  not  required  to 
fulfill  the  regular  duties  of  an  operator.) 

Norwegian,  Danish,  and  Scandinavian  ves- 
sels were  particularly  affected  and  were  forced 
to  place  radio  on  many  ships  which  had  not 


i6o 


Radio  Broadcast 


been  equipped  before.  Recent  press  dis- 
patches state  that  the  Danish  Parliament  is 
considering  the  passage  of  legislation  similar  to 
the  British  act  in  order  that  their  ships  may 
not  be  handicapped,  as  foreign  vessels  visiting 
Danish  ports  will  then  be  required  to  comply 
with  the  laws. 

French  law  is  rather  involved,  being  designed 
to  conform  to  the  requirements  of  the  naval 
and  military  services  as  well  as  of 
the  merchant  marine. 

Especially  during  the  last  few  yfjfEE^ 
years,  the  world  has  greatly  felt  the  /sBCi 
need  of  new,  unified,  international  m^l^M 
radio  legislation  to  suit  present  condi-  Ifepiii 
tions  and  to  provide  for  the  future.      V  ~ 

The  framers  of  the  London  Con-  ^Hfc 
vention,  realizing  that  the  art  would 
grow  beyond  its  stage  of  development  in  1912, 
provided  in  part  as  follows: 

The  provisions  of  the  present  Convention  and 
of  the  Regulations  relating  thereto  may  at  any  time 
be  modified  by  the  High  Contracting  Parties  by 
common  consent.  Conferences  of  plenipotentiaries 
having  power  to  modify  the  Convention  and  the 
Regulations  shall  take  place  from  time  to  time; 
each  conference  shall  fix  the  time  and  place  of  the 
next  meeting. 

It  was  agreed  that  the  next  Conference 
should  be  held  at  Washington  in  191 7. 

Owing  to  the  war  it  was  decided  to  postpone 
the  Conference.  At  the  Peace  Conference  at 
Paris  in  1919,  the  following  agreement  was 
reached  with  respect  to  calling  an  International 
Electrical  Communications  Conference: 

The  Principal  Allied  and  Associated  Powers  shall, 
as  soon  as  possible,  arrange  for  the  convoking  of  an 
international  conference  to  consider  all  international 
aspects  of  communication  by  land  telegraphs,  cables 
and  wireless  telegraph,  and -to  make  recommenda- 
tions to  the  Principal  Allied  and  Associated  Powers 
with  a  view  to  providing  the  entire  world  with  ade- 
quate facilities  of  this  nature  on  a  fair  and  equitable 
basis. 

A  preliminary  conference  of  representatives 
of  Great  Britain,  France,  Italy,  Japan,  and  the 
United  States  was  held  at  Washington,  begin- 
ning in  October,  1920,  for  the  purpose,  among 
other  things,  of  preparing  an  agenda  for  the 
International  Electrical  Communications  Con- 
ference. The  reports  adopted  at  this  Confer- 
ence have  been  submitted  to  the  governments 
of  the  world  for  their  comments  and  the  United 
States  Government  has  received  many  replies. 

United  States  Representatives  accredited  to 


governments  which  have  not  as  yet  furnished' 
an  expression  of  their  views  concerning  these 
reports  have  been  instructed  to  endeavor  to 
obtain  a  statement  of  the  views  of  these  gov- 
ernments. 

The  replies  which  have  been  received  are 
being  studied,  and  careful  consideration  is  being 
given  to  the  matter  of  determining  when  fur- 
ther action  shall  be  taken  by  this  government 
with  respect  to  the  next  Interna- 
■  .  tional  Radiotelegraphic  Conference. 

A  short  time  ago  there  met  in  Brus- 
|PPB|k      sels  representatives  of  professional 
radio  telegraphist  associations  of  Bel- 
gium,  Denmark,  Great  Britain,  Hol- 
-^^W      land,  Greece,  Italy,  and  Sweden, and 
here  was  formed  The  International 
Federation  of  Radiotelegraphists. 
Realizing  the  great  need  of  new  International 
Legislation,  the  Federation  adopted  the  follow- 
ing resolution  on  behalf  of  its  members,  the  sea 
going  radiotelegraphists  of  the  world: 

1 .  To  secure  adequate  representation  on  any  inter- 
national authority  dealing  with  wireless  matters 
affecting  the  position  of  marine  radiotelegraph- 
ists. 

2.  To  secure  the  uniform  and  satisfactory  applica- 
tion of  wireless  telegraphy  on  board  ship  so  as 
to  assure  the  maximum  degree  of  safety  of  life 

at  sea. 

3.  Instructing  the  Secretary  to  demand  recognition 
by  the  International  Radiotelegraph  Conven- 
tion, and  to  ask  that  at  least  one  representative 
from  the  Federation  should  be  present  at  the 
next  Convention.  Fixing  the  basis  for  an  inter- 
national manning  scale. 

4.  Calling  for  the  introduction  of  uniform  classes 
of  certificates  by  the  International  Radiotele- 
graph Convention. 

5.  The  collection  and  dissemination  of  news  and 
information  regarding  the  state  of  the  profession, 
etc.,  in  various  countries. 

6.  That  the  operation  of  wireless  telegraphy  at  sea 
in  all  its  branches  be  performed  only  by  qualified 
operators. 

7.  That  the  English  and  French  languages,  be 
learned  by  operators. 

The  United  States  Government  has  received 
an  invitation  from  the  French  Government  to 
participate  in  the  International  Electrical 
Communications  Conference  which  it  is  pro- 
posed to  hold  at  Paris  this  year.  It  has  not 
yet  been  decided,  however,  whether  this  govern- 
ment will  accept  the  invitation  of  the  French 
Government,  and  an  announcement  concerning 
this  is  expected  shortly. 


Soldering  Your  Own 

By  W.  S.  STANDIFORD 


OF  THE  many  people  throughout 
i  the  United  States  and  Canada 
I  who  are  making  and  installing 
'  their  own  sending  and  receiving 
sets,  the  majority  are  compara- 
tively "new  to  the  game"  and  have  trouble  in 
getting  soldered  joints  that  will  remain  firm. 
It  is  of  great  importance  to  the  working  of  any 
radio  outfit  that  a  clear  path  for  the  electrical 
energy  {which  at  its  best  is  very  weak)  should  he 
provided,  so  that  no  buying  sounds  due  to  loose 
connections  are  heard  along  with  the  signals. 

Soldering  wires  on  variometers  and  other 
parts  is  easy,  once  the  knack  of  handling  a 
soldering  iron  is  learned.  It  is  better  for  those 
who  have  never  done  work  of  this  kind  to  try 
it  first  on  some  spare  pieces  of  copper  wires 
twisted  together.  Soldering  irons,  or  coppers 
as  they  are  termed,  range  in  weight  from  a  few 
ounces  to  several  pounds.  They  can  be  either 
made  or  bought.  The  lighter  ones  are  easier 
to  handle,  but  lose  their  temperature  very 
quickly  compared  to  the  heavier  irons. 
One  weighing  about  three  fourths  or  one 
pound  (shank  and  handle  not  included)  is 
about  right  for  most  radio  work.  The  soldering 
iron  shown  in  the  accompanying  photograph 
weighs  close  to  one  pound,  and  was  made  by 
the  writer  from  a  one-inch  copper  bar,  the  shank 
being  made  from  a  poker,  and  the  wooden  han- 
dle obtained  from  an  old  broom. 

In  order  to  do  good  work  in  soldering,  five 
things  are  essential.  The  point  of  a  soldering 
iron  has  to  be  coated  with  solder  or  "tinned," 
as  it  is  termed  by  men  who  make  a  living  doing 
this  work.  The  portion  to  be 
joined  must  be  made  very 
clean,  either  by  scraping  with 
a  piece  of  a  sharp  knife  blade 
kept  for  this  purpose,  or  filed, 
or  rubbed  with  emery  cloth — 
whichever  method  proves  the 
handier.  The  parts  that  need 
soldering  ought  to  be  heated 
above  the  melting  point  of 
solder.  In  ordinary  classes  of 
small  work,  such  as  soldering 
one  wire  to  another  or  sheets 
of  metal  to  other  sheets,  the 


heat  of  the  soldering  iron  itself  must  be  suffi- 
cient not  only  to  melt  the  solder,  but  also  to 
raise  the  temperature  of  the  metal  to  be  fas- 
tened together,  so  that  firm  joints  are  made. 

Do  not  let  your  iron  get  too  hot,  that  is,  red- 
hot;  or  it  will  not  take  up  any  solder  at  all. 
Lastly,  it  is  best  to  keep  the  iron  well  tinned 
at  all  times,  so  that  when  you  want  to  use  it, 
it  is  always  ready,  and  you  will  thus  save  time 
by  not  having  to  re-tin  it.  New  irons  sold  in 
hardware  stores  are  in  the  rough  state,  with  no 
tinning  upon  their  points.  Most  of  them  also 
have  no  handle,  which  has  to  be  bought  separ- 
ately. It  is  necessary  after  one  is  put  on,  to 
smooth  the  four  sides  of  the  iron  with  a  medium 
coarse  file  so  as  to  make  the  tin  stick  to  it. 
To  tin  these  sides,  put  the  iron  in  a  clear,  red 
coal  fire,  which  is  not  giving  off  any  smoke. 
Heat  it  until  nearly  red-hot.  When  it  has  the 
right  degree  of  heat,  the  solder  will  melt  in- 
stantly when  it  is  applied  to  the  iron.  At  this 
stage,  if  it  is  held  about  3  inches  away  from  the 
palm  of  the  hand,  the  heat  given  off  from  the 
hot  metal  may  be  felt.  This  will  serve  as  a 
guide  for  future  heatings  instead  of  touching 
solder  to  the  tool. 

Have  some  powdered  rosin,  together  with 
solder,  on  a  board.  Quickly  brighten  one  face 
of  the  soldering  iron  with  a  file  or  a  piece  of 
sandpaper  tacked  on  a  block  of  wood  and  then 
rub  it  rapidly  into  the  rosin  and  solder  mixture. 
The  surface  of  the  copper  bit  will  be  found  to 
have  taken  a  shiny  coating  of  solder.  Repeat 
this  process  with  the  other  sides  until  they  are 
tinned.    If  it  should  happen  that  a  soldering 


A  "tinned    soldering  iron  and  accessories 

Behind  the  iron  are  a  coil  of  wire  solder,  a  bar  of  "half-and- 
half"  solder  (composed  of  tin  and  lead),  a  strip  of  emery  paper 
tacked  on  a  wooden  block,  and  a  lump  of  sal  ammoniac 


Radio  Broadcast 


TO  SEE  YOUR  APPARATUS  GROW  UNDER  YOUR  HAND 
From  a  heterogerieous  mess  of  parts  into  a  neat,  well-soldered  radio 
receiver,  and  to  connect  up  that  receiver  and  pull  in  signals — distant 
signals — that    is   truly   a   "gr-r-rand   and    glor-r-rious   feelin' " 


iron  refuses  to  take  a  tin  coat,  heat  the  copper 
a  bit  more,  but  not  red-hot;  file  its  face  and  rub 
it  on  a  lump  of  sal-ammoniac  to  remove  any 
grease,  then  plunge  into  the  rosin  and  solder 
flux.  A  few  trials  will  enable  any  novice  to 
do  good  tinning  work. 

Once  the  nose  of  an  iron  is  "tinned",  it  will 
remain  so,  provided  it  has  not  been  overheated 
so  as  to  burn  off  the  solder  or  cause  it  to  become 
alloyed  with  the  copper.  This  condition  can 
be  easily  recognized  because  the  surface  of  the 
copper  turns  black.  If  this  occurs,  file  and 
re-tin  the  four  sides. 

Having  coated  the  tool  with  tin,  you  can 
proceed  to  use  it  on  the  wires  of  your  radio 
outfit,  it  being  presumed  that  you  will  have 
practiced  soldering  other  pieces  of  wire  before 
trying  this  work  on  your  apparatus.  A  de- 
scription of  fluxes  and  their  action  will  be 
touched  upon,  as  fluxes  play  a  most  important 
part  in  soldering  work.    The  main  reason  for 


using  fluxes  in  order  to  make  joints 
that  will  not  become  loose,  is  that 
a  thin  film  of  oxide  always  forms 
upon  all  brightened  surfaces  of 
metals,  this  oxide  being  caused  by 
action  of  the  air.  Fluxes  dissolve 
and  prevent  any  further  oxide  form- 
ing and  thus  allow  the  solder  to  stick 
directly  to  the  metallic  body,  in- 
stead of  to  an  oxide  film  which, 
sooner  or  later,  allows  the  joints 
to  come  apart. 

To  solder  twisted  wires  on  vario- 
couplers,  untwist  the  ends,  scrape 
the  insulation  off  the  ends,  and 
brighten  them  with  emery  or  sand- 
paper. Then  coat  them  with  rosin 
flux,  taking  care  not  to  get  any  of 
it  on  the  insulation.  Heat  the  iron 
in  a  gas  or  coal  fire  until  it  has 
acquired  the  right  temperature, 
when  the  solder  on  its  tinned  sur- 
face will  be  observed  to  melt.  This 
shows  it  to  be  hot  enough.  Re- 
move it  from  the  fire,  give  it  a  quick 
rub  on  a  piece  of  old  carpet  or 
heavy  rag  and  touch  it  to  a  bar  of 
solder.  A  drop  of  the  latter  will 
adhere  to  the  iron  and  can  be  con- 
veyed to  the  wires  that  need  uniting. 
Hold  the  hot  copper  on  the  junc- 
tion. As  soon  as  the  wires  are 
hot  enough,  the  solder  will  leave 
the  iron  and  flow  over  them.  Re- 
move the  iron,  but  do  not  disturb  the  joint  until 
the  solder  has  set.  This  will  be  shown  by  a 
sudden  dulling  of  its  surface.  It  may  be  neces- 
sary to  add  more  solder  to  the  joint.  In  this 
case,  add  more  flux  and  put  on  another  drop 
of  metal. 

Some  radio  fans  use  aluminum  wires  for 
aerials  and  try  to  solder  the  joints  with  ordin- 
ary "half-and-half"  tinner's  solder  and  then 
wonder  why  it  does  not  stick  to  the  wires. 

Aluminum  has  an  oxide  on  its  surface  which 
reforms  as  quickly  as  it  is  removed.  For  this 
reason  a  special  solder  is  needed.  If  possible, 
a  radio  enthusiast  who  desires  to  use  an  alu- 
minum wire  aerial  should  have  a  wire  long 
enough  to  reach  the  binding  posts  of  his  set 
without  any  soldered  connections  in  it.  Should 
this  be  impracticable,  then  resort  will  have  to 
be  made  to  a  soldered  lead-in  wire.  If  this 
work  is  done  with  a  solder  and  flux  of  the  for- 
mula given,  aluminum  wires  may  be  united  with 


Soldering  Your  Own 


163 


little  trouble.  The  formula  for  aluminum  sol- 
der is  79  per  cent,  tin,  20  per  cent,  zinc,  and  1 
per  cent,  aluminum.  Obtain  a  dry,  grooved 
board  with  a  slot  cut  in  it  the  thickness  of  a 
lead  pencil.  Stop  up  both  ends  and  pour  the 
hot  metal  from  the  iron  ladle  into  it.  The 
flux  is  composed  of  equal  parts  of  stearic  acid 
and  rosin,  melted  together  and  well  stirred. 
A  bar  of  common  yellow  laundry  soap  melted 
up  with  a  sufficient  amount  of  rosin  so  as  to 
make  a  mixture  that  can  be  spread  on  with  a 
stick,  will  also  make  a  good  flux. 

Heat  the  place  on  the  wire  with  a  blow  torch 
until  it  is  hot  enough  to  melt  the  solder  (which 
differs  in  the  ordinary  variety  in  that  it  flows 
more  sluggishly),  then  quickly  rub  the  hot  sur- 
face with  flux  and  tin  it  well  with  the  solder, 


pushing  the  latter  backward  and  forward. 
This  removes  the  oxide  and  prevents  any  more 
from  forming.  When  both  wires  are  thor- 
oughly "tinned,"  wind  one  over  the  other  in 
the  usual  manner.  Heat  the  joint  again  and 
apply  more  flux  and  solder  so  as  to  cover  both 
parts  well.  In  aluminum  soldering,  it  is  better 
to  have  each  wire  covered  with  a  plentiful  sup- 
ply of  solder  so  as  to  exclude  moisture.  This 
solder  will  impart  a  strength  to  a  joint  nearly 
equal  to  the  strength  of  the  metal  itself.  An 
aluminum  soldering  "iron"  will  be  found  to 
work  better  than  a  copper  one,  although  the 
latter  can  be  used  successfully  for  aluminum 
work.  Joints  on  outside  aerials  should  be 
painted  with  several  coats  of  spar  varnish,  to 
keep  out  the  moisture. 


TESTING  TELEPHONE  RECEIVERS 
In  the  factory  of  the  Holtzer-Cabot  Company.    The  operator  is  able  to  determine  the  tone  quality,  distortion,  and  volume  • 
of  the  receivers,  directly  from  the  meters,  as  readily  as  one  can  determine  resistance  by  the  use  of  a  Wheatstone  Bridge 


Broadcast  Receiving  Contest! 


Any  Number  of  Tubes — Any  Kind  of  Receiver 

THE  LONG-DISTANCE  RECEIVING  CONTEST,  to  determine  who  has  done  the  best  with 
ANY  NUMBER  OF  TUBES  AND  ANY  TYPE  OF  RECEIVER,  is  in  full  swing.  The 
drawbridge  will  be  hauled  up  at  sunset  on  MA  Y  31st,  however,  and  after  that  even  the  most  imposing- 
looking  contributions  will  have  to  be  left  outside  the  portcullis.  A  great  many  of  them  will  probably 
gallop  through  in  a  cloud  of  dust  at  the  last  minute — but  that  is  dangerous  business,  and  we  advise 
you  not  to  try  it.    Read  through  the  Eight  Commandments  below,  roll  up  your  sleeves,  and  go  to  it. 

The  Four  Prizes 

First  Prize:  DE  FOREST  D-7  REFLEX  LOOP  RECEIVER 
This  receiver,  described  in  RADIO  BROADCAST  for  February  (page  297),  is  the  latest  product 
of  the  De  Forest  Company:  it  makes  three  amplifying  tubes  and  a  crystal  detector  do  the  work  of  six 
tubes.  The  loop  antenna  aids  in  selectivity  because  of  its  directional  properties.  An  ordinary  antenna 
and  ground  may  be  used,  however,  if  desired.  Recently,  a  man  in  Brooklyn,  N .  Y .  heard  a  broadcast- 
ing station  in  Seattle,  Wash.,  with  one  of  these  sets. 

Second  Pri^e:  GREBE  TUNED  RADIO-FREQUENCY  AMPLIFIER,  TYPE  l'RORN" 
This  amplifier,  which  has  a  wavelength  range  of  from  150  to  3000  meters,  may  be  used  with 

any  form  of  home-made  or  bought  receiver.    It  is  the  most  recent  development  of  a  company  widely 

known  for  the  excellence  in  design  and  workmanship  of  its  products. 

Third  Pri^e:  Choice  of 

THREE  OF  THE  NEIV  RADIOTRON  UV-201-A  AMPLIFIER  TUBES  (6  volts,  f  of  an 
ampere),  or 

THREE  AERIOTRON  IVD-u  DRY  CELL  TUBES  (V*  volts,  \  of  an  ampere). 
Fourth  Priie:  TIMMONS  LOUD-SPEAKER  UNIT 

This  unit,  which  may  be  connected  directly  to  the  output  of  your  amplifier,  has  a  diaphragm  ad- 
justable for  sounds  of  different  intensities,  and  when  used  with  two  stages  of  amplification  reproduces 
broadcast  programs  about  as  loud  as  the  music  from  the  average  phonograph. 

Rules  of  the  Contest 

/.  You  should  list  all  broadcasting  stations  1 50  or  more  miles  away  from  the  receiving  point,  which 
you  have  heard  distinctly  (announcement  of  location  as  well  as  of  call  letters.) 

2.  Measure  distances  accurately,  and  give  aggregate  mileage.  (This  is  the  sum  of  all  the 
distances,  each  station  counted  once,  but  two  or  more  stations  in  the  same  city  being  counted  separ- 
ately.)   An  aggregate  mileage  of  less  than  15,000  miles  will  not  be  considered. 

3.  Manuscripts  should  include  the  following:  description  of  set,  directions  or  advice  for  con- 
structing and  operating  it;  any  "wrinkles"  or  makeshifts  which  you  have  used  to  advantage;  photo- 
graph of  your  apparatus;  circuit  diagram;  in  general,  anything  you  have  to  tell  that  will  make  your 
story  more  interesting  and  helpful.  Manuscripts  should  not  be  longer  than  2000  words.  Typewritten 
ones  preferred. 

4.  Data  should  be  arranged  in  three  columns,  under  the  headings:  call  letters,  location,  distance. 

5.  For  material  used,  a  liberal  rate  will  be  paid. 

6.  In  judging  contributions,  the  quality  and  interest  of  photographs,  text,  and  drawings,  and  the 
originality  and  general  effectiveness  of  the  apparatus  described,  will  have  greater  weight  than  the  list  of 
stations  heard,  although  a  long  list  of  distant  stations  will  distinctly  help. 

7.  The  Contest  closes  May  31st,  1923. 

8.  Address:  Receiving  Contest,  RADIO  BROADCAST ,Doubleday,  Page&Co.,GardenCity,  N.  Y. 


ONE  of  the  best  books  designed  to 
i  assist  the  broadcast  listener  and 
I  the  amateur  to  know  who  is  on 
'  the  air  is  "The  Citizens'  Radio 
Call  Book."  It  contains  the  call 
letters  of  American  and  Canadian  Broadcasting 
and  Amateur  Stations;  Experimental  and 
College  Stations;  Naval  Radio  Stations; 
press  schedules  of  radio  stations  through- 
out the  world  and  a  list  of  high-power  trans- 
ocean  stations.  It  is  arranged  in  a  very 
convenient  manner  and  is  well  worth  its  price: 
fifty  cents. 

Citizens  Radio  Service  Bureau,  416  So. 
Dearborn  St.,  Chicago,  111. 

In  a  thirty-two  page  booklet  called  "Getting 
Acquainted  with  Radio  Receivers,"  Paul  God- 
ley  has  told  a  great  deal  about  the  use  of  re- 
ceivers for  broadcast  reception.  Mr.  Godley's 
work  is  truly  a  short  course  in  radio-electricity. 
Much  of  the  book  is  devoted  to  the  installation 
and  operation  of  "Paragon"  receivers,  but 
there  is  a  wealth  of  information  which  will  be 
found  valuable  by  the  operator  of  any  type  of 
regenerative  receiver.  The  book  may  be  had 
for  twenty-five  cents. 

Adams-Morgan  Company,  Upper  Montclair, 
New  Jersey. 

"  Radio  Reception"  by  Harry  J.  Marx  and  J. 
Adrian  Van  Muffling,  is  a  real  radio  book  and 
is  full  of  practical  information  for  the  fellow  who 
builds  his  own.  It  is  simple  and  complete  and 
well  illustrated.  The  book  contains  92  illus- 
trations and  38  diagrams,  and  includes  a  brief 
outline  of  applied  radio-frequency  amplifica- 
tion. 


G.  P.  Putnam's  Sons,  New  York  City. 
Price  S2.00. 

A  rather  complete  book  on  radio  from  the 
early  days  to  the  present,  from  crystal  receivers 
and  double-slide  tuners  to  super-regeneration 
and  the  transmission  of  photographs  by  radio 
is  Dr.  Henry  Smith  Williams'  "  Practical 
Radio."  There  are  a  great  many  illustrations 
which  serve  their  purpose  admirably.  The 
functions  of  various  radio  devices  are  clearly 
and  correctly  portrayed  and  described  in  a 
helpful  and  interesting  manner.  Here,  indeed, 
is  a  volume  of  worth  for  the  beginner  and  the 
more  advanced  enthusiast.  It  is  just  what  its 
name  implies — Practical  Radio. 

Funk  &  Wagnalls  Company,  New  York  City. 
Price  $1.75  ($1.87  postpaid). 

"Letters  of  a  Radio  Engineer  to  His  Son"  is 
a  book  designed  for  those  who  would  under- 
stand the  reason  for  various  actions  that  take 
place  in  a  vacuum  tube  whether  it  be  employed 
for  receiving  or  transmitting.  John  Mills,  the 
author,  has  told  this  story  in  a  very  complete 
and  comprehensive  manner,  but  these  letters 
would  hardly  interest  the  average  son  unless  he 
is  well  along  in  high  school.  If  the  book  you 
seek  is  one  on  "how  to  make  it,"  this  is  not  the 
book  for  you,  for,  although  it  explains  design 
in  a  complete  manner,  no  attempt  is  made  at 
assembly  and  panel  layout.  There  are  more 
helpful  books  for  those  who  build  their  re- 
ceivers and  transmitters  from  standard  parts, 
but  for  the  person  who  takes  pleasure  in  design- 
ing his  own  units  this  work  is  of  great  value. 

Harcourt,  Brace  &  Company,  New  York.. 
Price  $2.00. 


All  Boy  Scouts,  Attention! 

RADIO  BROADCAST  announces  a  contest,  starting  now  and  ending  July  )i ,  iQ2i,  to  determine 
WHAT  BOY  SCOUT  TROOP  HAS  DONE  OR  IS  DOING  THE  MOST  WITH  RADIO. 


Prizes  for  Winning  Articles 

FIRST  PRIZE:    CROSLEY  MODEL  X  4-TUBE  RECEIVER. 

This  receiver,  which  may  he  used  with  dry-cell  tubes  if  desired,  consists  of  detector,  one  stage  of 
tuned  radio-frequency  and  two  stages  of  audio-frequency  amplification.  {Advertised  in  Radio 
Broadcast). 

SECOND  PRIZE:    MUSIC  MASTER  LOUD  SPEAKER. 

This  is  the  new  loud  speaker  made  by  the  General  Radio  Corporation.  {A  picture  and  description 
of  it  appear  in  the  advertising  pages  of 

THIRD    PRIZE:  THREE 

The  WD-11  is  the  well-known  dry- 
Corporation.    (Filament  voltage  1.5, 

A  YEAR'S  SUBSCRIPTION  TO 
given  as  prices  for  the  ten  next  best 

These  prices  will  be  awarded  to 
troop  may  delegate  one  of  its  members  to 


Rules  of 

/.  Articles  must  be  true  accounts  of  radio  with  relation  to  your  particular  troop:  what  you  have  done,  or  are 
doing,  or  both. 

2.    Every  article  must  be  written  by  a  Scout  or  by  more  than  one  Scout  belonging  to  one  troop, 
j.    Articles  should  be  between  500  and  1000  words  long. 

4.  Good  photographs  to  illustrate  the  article  will  count  50%  in  judging  contributions. 

5.  Typewritten  manuscript,  double-spaced,  is  desired,  though  not  required. 

6.  Address  contributions  to  Scout  Contest,  Radio  Broadcast,  Doubleday,  Page  &  Company,  Garden  City,  N.  Y. 

Scouts  have  done  splendid  work  in  maintaining  communication  by  radio  in  time  of  floods  and  disaster,  in 
copying  and  spreading  the  market  reports  transmitted  by  the  government  Farm  Bureaus,  in  training  themselves 
along  mechanical  and  electrical  lines,  and,  in  short,  in  using  radio  as  a  part  of  scout  work  in  a  way  consistent 
with  the  best  traditions  of  scouting.  What  have  you,  to  tell  of  your  troop's  past  or  present  activities?  Get  your 
scribes  and  photographers  under  way  with  that  story  which  will  put  in  a  strong  bid  for  first  pri^e.  How  would 
a  receiver  with  three  stages  of  amplification  go  in  your  troop? 

Beginning  with  the  July  number  of  Radio  Broadcast,  the  best  articles  will  be  published.  The  winners 
will  be  announced  in  the  September  number,  and  unless  the  three  best  articles  have  been  previously  published, 
they  will  appear  in  that  issue. 


Next  Month — More  About  the  Grimes  Circuit 

The  article  by  Mr.  Charles  H.  Durkee  in  our  April  number,  "1300  Miles  on  a  One- 
Foot  Loop,"  resulted  in  a  deluge  of  correspondence  from  interested  readers.  The  article 
described  the  "Inverse  Duplex"  receiver  developed  by  Mr.  David  Grimes,  ofStaten  Island, 
N.  Y. 

Radio  Broadcast  has  arranged  to  have  Mr.  Grimes  explain  to  you,  next  month,  how 
you  can  construct  this  receiver  and  how  it  should  be  adapted  for  use  with  various  types  of 
tubes  now  on  the  market.    It  is  the  ideal  vacation  outfit. — The  Editor. 


Radio  Broadcast). 

WD-11  VACUUM  TUBES. 

cell  tube  manufactured  for  the  Radio 
plate  voltage  22XA — 45). 

"RADIO  BROADCAST"  will  be 
contributions  in  this  contest. 

troops,  not  to  individuals,  although  any 
prepare  the  story. 


the  Contest 


New  Wavelengths  for  Class  B 

Stations 

Revised  Schedule,  Issued  by  Department  of  Commerce,  in  Effect  on  May  15th 


TO  CLEAR  up  the  congestion  in  radio 
broadcasting,  says  the  New  York 
Times,  a  new  schedule  of  wave- 
lengths, going  into  effect  on  May  15, 
has  issued  from  the  Department  of 
Commerce,  which  has  been  working  on  the 
problem  ever  since  the  recent  National  Radio 
Conference. 

Definite  wavelengths  have  been  allocated 
to  each  of  five  zones  into  which  the  country 
has  been  divided,  and  broadcasting  stations  will 
have  to  adhere  to  these  or  suffer  the  penalty 
of  loss  or  suspension  of  license. 

For  the  Class  B  stations  (the  high-power 
transmitting  agencies)  there  will  be  ten  wave- 
lengths in  each  zone,  and  each  of  these 
will  be  adjusted  so  as  not  to  conflict  with  any 
other. 

Of  the  ten  zone  lengths  assigned  to  Zone  1 , 
which  extends  from  New  England  through  the 
District  of  Columbia,  three  of  them,  405,  455, 
and  492  meters,  have  been  assigned  to  New 
York  City  and  Newark.  This  is  because  so 
many  persons  are  served  by  the  stations  in 
the  neighborhood,  and  so  much  entertainment 
talent  is  available.  The  stations  in  New  York 
and  Newark  will  have  to  arrange  for  division  of 
time. 

Other  assignments  of  wavelengths  thus  far 
in  this  zone  are: 

Springfield,  Mass.  (Westinghouse  station) 
and  Wellesley  Hills,  Mass.,  337  meters. 

Schenectady  (General  Electric),  and  Troy 
(Rensselaer  Polytechnic),  380  meters;  Phila- 
delphia (Wanamaker's,  Lit's,  Strawbridge  & 
Clothier),  509  and  395  meters,  and  Washing- 
ton (Arlington  and  Radio  Corporation),  435 
meters.  It  is  likely  that  Arlington  will  have  a 
special  wavelength  and  not  be  forced  to  divide 
time  with  any  other  station.  Wavelengths  of 
303,  319,  469  meters  also  are  reserved  for  this 
zone. 

Assignments  in  the  other  zones  up  to  this 
time  are: 

Zone  2 — Pittsburgh,   326;   Chicago,  448; 


Davenport  and  Des  Moines,  484;  Detroit  and 
Dearborn,  517;  Cleveland  and  Toledo,  390; 
Cincinnati,  309;  Madison  and  Minneapolis, 
417. 

Zone  3 — Atlanta,  429;  Louisville,  400;  Mem- 
phis, 500;  St.  Louis,  546. 

Zone  4 — Lincoln,  Neb.,  341;  Kansas  City, 
411;  Jefferson  City,  441;  Dallas  and  Fort 
Worth,  476;  San  Antonio,  385;  Denver,  323; 
Omaha,  527. 

Zone  5 — Seattle,  492;  Portland,  455;  Salt 
Lake  City,  312;  San  Francisco,  509  and  423; 
Los  Angeles,  395  and  469;  San  Diego,  536. 

NOTHING  ABOVE  6oO 

None  of  the  wavelengths  goes  above  600 
meters.  This  is  important  to  amateurs,  as 
according  to  a  plan  proposed  to  the  recent  con- 
ference the  large  stations  might  have  had 
wavelengths  up  to  700  meters,  which  would 
have  necessitated  the  changing  over  of  many 
receiving  sets. 

Besides  the  Class  B  stations,  which  broad- 
cast to  long  distances,  there  are  540  Class  A 
stations  which  use  the  360-meter  wavelength. 
These  will  be  allowed  to  retain  that  wavelength 
or  can  come  into  a  special  band  between  222 
and  300  meters.  If  a  new  station  is  erected 
and  it  cannot  meet  the  qualifications  of  a 
Class  B  station  it  will  not  be  allowed  to  use 
360  meters,  but  must  go  into  the  222-300 
band. 

Because  of  the  great  activity  in  radio,  the 
Department  of  Commerce  is  enlarging  its  forces 
in  the  inspection  districts  of  which  there  are 
nine  with  Boston,  New  York,  Baltimore, 
Atlanta,  New  Orleans,  San  Francisco,  Seattle, 
Detroit,  and  Chicago  as  headquarters. 

Beginning  May  15,  inspectors  will  check  the 
wavelengths  of  stations  in  their  districts. 

It  was  stated  that  any  station  now  operating 
on  360  meters  has  the  privilege  of  remaining 
on  that  wavelength.  It  is  also  emphasized 
that  the  assignments  of  wavelengths  are  for 
cities  and  not  for  specific  stations. 


The  Grid 


QUESTIONS  AND  ANSWERS 

The  Grid  is  a  Question  and  Answer  Department  maintained  especially  for  the  radio  amateurs.  Full 
answers  will  be  given  wherever  possible.  In  answering  questions,  those  of  a  like  nature  will  be  grouped 
together  and  answered  by  one  article.  Every  effort  will  be  made  to  keep  the  answers  simple  and  direct, 
yet  fully  self-explanatory.  Questions  should  be  addressed  to  Editor,  "The  Grid,"  Radio  Broadcast, 
Garden  City,  N.  Y.  The  letter  containing  the  questions  should  have  the  full  name  and  address  of  the 
writer  and  also  his  station  call  letter,  if  he  has  one.    Names,  however,  will  not  be  published. 


LOOPS 

The  writer  would  appreciate  publication,  in  an  early 
issue  of  Radio  Broadcast,  of  information  concerning  the 
construction  of  a  loop  antenna. 

H.  H.  S.,  Pittsburg,  Pa. 

IN  WRITING  to  The  Grid  for  constructional  data,  cor- 
I  respondents  are  requested  to  furnish  the  editor  with  all 
1  possible  information  concerning  the  use  to  which  the  ap- 
paratus is  to  be  put.  This  should  include,  when  pertinent, 
frequency  (supply  line),  wavelength,  voltage,  current, 
sizes,  the  experience  of  the  correspondent  and  a  description 
of  available  material.  This  will  greatly  add  to  the  facility 
with  which  our  advice  may  be  carried  out,  and  to  the 
general  usefulness  of  this  department.] 

It  is  assumed  that  our  inquirer  desires  to  construct  a  loop 
for  broadcast  reception.  The  most  desirable  size  for  such 
a  purpose  is  a  compromise  between  the  more  efficient  larger 
sizes  and  the  convenience  and  mobility  of  a  small  frame — 
a  square  loop,  three  feet  on  a  side,  the  various  dimensions 
of  which  are  indicated  on  the  working  drawing  of  Figure  i. 
The  loop  is  of  the  solenoid  type,  i.  e.,  wound  in  "box" 


FIG.  I 


Showing  dimensions  for  a  loop  for  broadcast  reception 


100 


20°  40°  60°  80°    100°  120°  140°  160°  180° 
.0005  MFD  WITH  ft  COMPARATIVELY   STRAIGHT  CURVE 

FIG.  2 

form  rather  than  as  a  spiral.  There  are  nine  turns  of 
wire,  separated  one-half  inch,  wound  in  grooves  sawed  in 
the  end  pieces.  Any  convenient  wire  may  be  used.  Green 
double  silk  covered,  number  eighteen,  is  perhaps  the  most 
easily  manipulated,  and  when  wound  on  a  stained  frame,  the 
finished  loop  presents  a  very  creditable  appearance. 

The  frame  is  constructed  of  one  by  one-and-a-half 
inch  lumber.  The  upright  may  be  drilled  at  the  lower 
support  on  which  the  wires  are  strung  to  pass  the  middle 
wire.  The  other  wires  of  course  pass  on  either  side  of  the 
upright.  The  construction  of  the  base  is  clearly  shown,  the 
holes  through  the  top  and  into  the  bottom  being  one  inch 
in  diameter,  and  the  lower  eight  inches  of  the  upright 
rounded  to  fit  with  sufficient  looseness  to  permit  turning. 

Figure  2  shows  the  approximate  wavelength  range  of  this 
loop  when  shunted  by  the  average  .0005  mfd.  plate  con- 
denser. 

The  indoor  loop,  as  described,  will  give  satisfactory 
results  only  when  used  with  radio-frequency  amplification. 
Employing  two  stages  of  transformer-coupled,  or  one 
stage  tuned  plate  R.  F.  amplification,  detector  and  two 
steps  of  audio-freqeuncy  amplification,  stations  one 
thousand  miles  distant  should  be  received  with  very  good 
audibility. 

A.  C.  FOR  RECEIVING  FILAMENTS 

Is  there  any  possible  way  in  which  I  can  light  the  filament 
of  my  detector  bulb  from  110  volts  alternating  current  ?  I 
thought,  perhaps,  the  A.  C.  could  be  stepped  down  to  six 
volts  by  a  transformer,  and  this  changed  to  direct  current 
through  a  rectifier.    Choke  coils  would  be  used  to  smooth  out 


A  Millionaire's  Cruise  on  an  Operator's  Pay 


25  Cents 


Published  by 


DOUBLEDAY,  PAGE  85  CO. 


Garden  City,  N.  Y. 


Filament  Current  .06 
amp.  Mutual  Conduct- 
ance 337  Micromhos  at 
40  volts  plate  and  0 
grid  potential. 


Cut  shows  actual  size  of  tube 
3  inches  high 


Type  C-299 
Price  $6.50 


Announcing  the  New 


* 


Dry  Battery  Detector  and  Amplifier  Tube 

Designed  by  the  engineers  of  the  General  Electric  Company's  great  research  laboratories,  this 
new  dry  battery  tube,  type  C-299,  is  by  far  the  most  economical  vacuum  tube  ever  placed  on  the 
market  for  -amateur,  experimental  and  entertainment  use. 

It  has  been  designed  for  use  as  a  Detector  and  Amplifier  of  both  radio  and  audio-frequency 
currents,  the  filament  is  lighted  from  three  1V2  volt  dry  batteries  in  series,  and  the  filament 
current  is  only  .00  of  an  Amp.  This  is  less  than  one  fourth  of  the  current, of  any  previous  type 
of  dry  battery  tube.  This  feature  makes  it  possible  to  use  four  of  these  tubes  in  parallel,  with 
only  one  set  of  three  dry  batteries. 

The  C-299  has  practically  the  same  operating  characteristics  as  the  previous  Cunningham 
Amplifier,  type  C-301.  Due  to  the  low  distributive  capacity  of  the  elements  it  is  an  excellent 
radio-frequency  amplifier.  When  used  as  an  audio-frequency  amplifier  the  output  from  two 
steps  is  sufficient  for  the  operation  of  a  small  loud  speaker. 

Bulletin  No.  2-B  describes  this  new  tube  in  full  and  gives  the  necessary  data  regarding  rheo- 
stats, battery  voltages,  transformers,  etc.  A  free  copy  will  be  sent  to  you  by  return' mail,  upon 
receipt  of  your  request  at  either  of  the  addresses  given  below.  Complete  instruction  sheet  for  its 
care  and  operation  is  packed  with  each  of  these  New  Cunningham  Dry  Battery  Tubes,  type  C-299. 


248  First  Street,  San  Francisco,  Calif. 


154  W.  Lake  Street,  Chicago,  Illinois 


Tested  and  approved  by  Radio  Broadcast  + 


1 


RADIO  BROADCAST  ADVERTISER 


The  justly  famous  Crosley 
Model  VI,  a  two  tube  set  incor- 
porating one  stage  of  tuned 
radio  frequency  amplification 
and  detector,  price — $28.00. 


A, 

one  Reason 

why 

RADIO  RECEIVERS 
are 

so  much  better 

The  heart  of  any  receiver  is  the  variable  con- 
denser. The  superiority  of  the  Crosley  book- 
type  variable  condenser  over  the  old  type  in- 
terlocking plate  air  condenser  is  now  generally 
admitted  for  the  following  reasons: 

1.  Rugged  construction  that  prevents  damage. 

2.  Freedom  from  short  circuits. 

3.  Permanent  metallic  contact  with  plates  eliminates 
sliding  contacts. 

4.  Minimum  stray  electrostatic  field  eliminates  body 
effects  when  tuning. 

5.  Liberal  leakage  paths  through  condenser. 

6.  Grounded  frame  provides  electrostatic  shield. 

7.  Minimum  high  frequency  resistance  or  energy  loss. 

8.  Maximum  variation  in  wave  length  with  fixed  coil. 

9.  Maximum  mechanical  and  electrical  efficiency. 
10.    Minimum  cost. 

We  state  positively  that  the  substitution  of  a 
Crosley  condenser  for  any  other  type  of  com- 
mercial receiving  condenser  in  any  receiving  set 
or  circuit  will  greatly  increase  the  range,  vol- 
ume and  simplicity  of  tuning. 


The  Standard  Model  X  that  has  made 
history  during  the  past  year,  and  is  now 
recognized  as  the  most  efficient  set  on 
the  market,  will  be  continued  at  the 
same  price,  $55.00,  notwithstanding  the 
advanced  cost  of  materials. 

We  announce  a  new  Model  X,  to  be 
designated  as  Model  X-J,  equipped  with 
head  phone  jacks  for  detector  and  one 
stage  of  amplification,  in  addition  to 
loud  speaker  binding  posts. 

The  instrument  has  been  redesigned  in- 
ternally with  new  molded  sockets,  con- 
densers having  molded  plates,  rheostats 
in  molded  shells,  new  dials,  price,  $65.00. 


New  Crosley  type  D  Condenser 
has  molded  plates.    Price  $2.25. 


Old-fashioned  multiple  plate  con- 
denser which  has  been  largely  re- 
placed by  Crosley  type  D. 


New  York  Office,  C.  B.  Cooper,  1803  Tribune  Bldg., 

154  Nassau  Street 
Boston  Office,  B.  H.  Smith,  929  Blue  Hill  Ave.,  Dorchester 
Chicago  Office,  1311  Steger  Bldg.,  28  E.  Jackson  Blvd., 
R.  A.  Stemm,  Mgr. 


Crosley  receivers  incorporating  tuned  radio  frequency  amplification  reduce  static  and 
other  interference  to  a  wonderful  degree,  which  greatly  increases  summer  receivingrange. 

CROSLEY  MANUFACTURING  CO. 

720  Alfred  Street  Cincinnati,  Ohio 


i  ested  and  approved  by  Radio  Broadcast 


Radio  Broadcast 


ARTHUR  H.  LYNCH,  Editor 


CONTENTS  FOR  JULY,  1923 

"Resolved:  That  the  Volstead  Act  Should  Be  Repealed"    -    --    --    --    --  Frontispiece 

THE  MARCH  OF  RADIO    --------------------  ng 

MAKING  RADIO  YOUR  BUSINESS     ----------     Carl  Dreher  190 

USING  THE  "INVERSE  DUPLEX"  WITH  VARIOUS  KINDS  OF  TUBES 

David  H.  Grimes  197 

RADIO  IS  EXPENSIVE  FOR  THE  MARRIED  MAN     -   -   -   -  Robert  Oliver  202 

PUTTING  YOUR  PATENT  ACROSS  -   -     Roger  Sherman  Hoar  205 

THE  SET  THE  BOY  AND  HIS  DAD  MADE    ------    Arthur  N.  King  210 

R.  F.  AMPLIFICATION  WITHOUT  DISTORTION  OR  RERADIATION 

Edward  Lindley  Bowles  214 

A  PORTABLE  SET  FOR  LONELY  HOTEL  HOURS  -------     J.  T.  N.  219 

A  MILLIONAIRE'S  CRUISE  ON  AN  OPERATOR'S  PAY  -    -   -   -       A.  Henry  222 

A  HOME-MADE  AMPLIFIER  FOR  ANY  RECEIVER    -----     Zeh  Bouck  230 

THE  "HOW  FAR  HAVE  YOU  HEARD?"  CONTEST     -   -   -   234 

WEAF'S  NEW  HOME  ----------------------  239 

BOY  SCOUTS'  RECEIVING  CONTEST    -   -  -   -   -   -   -   -  240 

REDUCING  THE  GUESSWORK  IN  TUNING  ------     J.  H.  Dellinger  241 

RECENT  BROADCASTERS  IN  NEW  YORK  STUDIOS     ---------  246 

DRY  CELLS  AND  UV-199's     ---------   -   -   -   -     E.  E.  Horine  247 

WHAT  RADIO  HOLDS  FOR  BOY  SCOUTS  -  Arthur  H.  Lynch  251 

RADIO  BROADCAST  CENTRAL  ----------      Pierre  Boucheron  254 

THE  GRID— QUESTIONS  AND  ANSWERS   256 

ADDITIONAL  BROADCASTING  STATIONS  IN  THE  UNITED  STATES    -   -   -  260 

NEW  EQUIPMENT-   -j  ----------------  262 

AMONG  OUR  AUTHORS    ---------/-----------  264 


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RADIO  BROADCAST  ADVERTISER 


PERFECT 

FILAMENT 

CONTROL 


0 
a 

'C-300, 


C-301 


for  the 


C-301-A, 


WD-11 


WD-12 


UV-200 
UV-201 


UV-201A1 


A  Perplexing  Problem  Solved ! 

TRY  any  tube  in  your  radio  set!  It  makes  no  diSerence  what  tube  is  used,  the 
new  universal  Bradleystat  with  three  terminals  will  give  perfect  filament  control. 
A  very  simple  change  of  connections  and  a  remarkable  range  of  control  make  this 
possible  for  the  first  time  in  radio  history.  Like  former  Bradleystat  models,  the  new 
universal  Bradleystat  with  three  terminals  is  covered  by  the  same  iron-clad  guarantee 
of  perfect  performance,  noiseless  control  and  quicker  tuning  that  sold  hundreds  of  thous- 
ands of  Bradleystats  during  the  past  year. 


UV-199 


Be  prepared  to  try  any  new  tube  by  replacing  your  present  rheostats  with 
the  new  universal  Bradleystat.  It  is  the  last  word  in  flexible  and  perfect 
control.  It  is  backed  by  twenty  years'  experience  with  graphite  disc  rheo- 
stats. Beware  of  imitations.  Avoid  the  use  of  inferior  carbon  powder  rheo- 
stats. The  name  "Bradleystat"  is  embossed  on  container  for  your  protection. 

Mail  the  coupon  below  for  full  information  about  the  latest  and  most  re- 
markable development  in  filament  control.  CLIP  THE  COUPON,  NOW! 


m  m 


ALLEN-BRADLEY  CO.        278  Greenfield  Ave.        MILWAUKEE,  WIS. 

I  am  pleased  to  hear  that  the  universal  Bradleystat  with  three  terminals  has  solved  the  perplexing  problem 
of  finding  one  rheostat  for  all  tubes.  This  is  good  news.  Please  send  me  lull  information  and  explain  how  it  is  done 


^  Tested  and  approved  by  Radio  Broadcast  ^ 


"RESOLVED,  THAT  THE  VOLSTEAD  ACT  SHOULD  BE  REPEALED' 

It  is  estimated  that  the  debate  between  Wayne  B.  Wheeler  (right),  General  Counsel  of  the  Anti-Saloon  League,  and 
Ransom  H.  Gillett  (left),  General  Counsel  of  the  Association  against  the  Prohibition  Amendment,  broadcasted  on  April 
18th  from  WEAF,  New  York,  was  heard  by  half  a  million  people.  This  was  the  first  time  that  two  such  leaders  of 
opposing  thought  faced  each  other  before  the  microphone  on  a  subject  of  national  interest  and  importance.  At  the  finish 
of  the  debate,  questions  submitted  by  the  audience  were  answered  by  the  speakers.  A  poll  of  WEAF's  audience  showed 
decisively  that  Mr.  Wheeler  won  the  debate,  and  that  the  personal  preference  of  the  radio  audience  on  the  question, 
"Should  the  Volstead  Act  be  Repealed5"  was  57%  "No"  and  43%  "Yes" 


©CI  8579415^ 


RADIO 
BROADCAST 

vol.  3  No.  3  'x^~^y*  ^u]y'  1923 

The  March  of  Radio 

VOLSTEAD  IN  THE  AIR 


IN  TRYING  out  the  radio  public  to  see  what 
they  like  and  what  they  don't  like,  WEAF, 
the  well-known  station  of  the  American 
Telephone  and  Telegraph  Company  in  New 
York,  recently  staged  a  debate  on  the  liquor 
question:  "Resolved,  that  the  Volstead  Act 
Should  be  Repealed." 

This  station  is  continually  experimenting 
with  broadcast  material,  not  only  with  the  idea 
of  giving  the  public  varied  entertainment,  but 
of  enabling  those  responsible  for  its  operation 
to  gauge  the  extent  of  the  public's  interest  in 
radio  and  to  endeavor  to  gather  reliable  sta- 
tistics as  to  what  kind  of  programs  the  public 
wants.  It  is  evidently  in  this  way  only  that 
proper  development  of  radio  entertainment  can 
be  brought  about — only  by  the  tone  of  the  cor- 
respondence received  can  the  manager  of  the 
station  judge  of  his  success  in  catering  to  the 
public's  desires.  The  American  Telephone  and 
Telegraph  Company  is  spending  many  thou- 
sands of  dollars  a  year  to  get  the  correct  answer 
to  the  question,  "  What  is  the  demand  for 
broadcasting?" 

The  debate  on  the  value  of  Mr.  Volstead's 
activities  was  brought  about  by  the  Govern- 
ment Club,  the  President  of  this  organization, 
Mrs.  Geo.  E.  Owens,  having  charge  of  the  pro- 
gram, introducing  the  speakers,  and  reading 
the  questions  sent  in  by  the  radio  listeners. 
The  public  had  been  told  to  send  in  questions 
as  the  debate  progressed  and  that  their  ques- 
tions would  be  answered,  as  far  as  possible,  by 


the  debaters.  The  debaters  were  Wayne  B. 
Wheeler,  general  counsel  of  the  Anti-saloon 
League  of  America,  and  Ransom  H.  Gillett, 
general  counsel  of  the  Association  Against  the 
ProhibitionAmendment.  That  the  question  was 
a  live  one  in  which  the  listeners  took  an  intense 
interest  soon  became  evident  as  the  questions 
poured  in;  only  a  small  fraction  of  them  could 
be  answered  in  the  time  allotted. 

As  we  listened  to  this  debate,  and  pictured 
the  invisible  audience  of  possibly  hundreds  of 
thousands,  the  great  utility  of  radio  for  po- 
litical campaigning  was  once  more  driven  home. 
The  questions  asked  by  the  listeners  showed 
thought — showed  that  the  debaters  were  being 
closely  followed  in  their  arguments  by  their 
vast  audience.  When  used  by  persons  aspiring 
to  governmental  positions  this  method  of  pre- 
senting their  virtues  will  prove  of  real  value  to 
those  of  worth,  and  should  show  up  at  the  same 
time  the  hollow  arguments  and  fallacies  of  the 
familiar  political  spell-binder.  Not  only  is 
this  scheme  of  contact  between  orator  and  pub- 
lic valuable  to  the  public,  allowing  them  to 
analyze  what  the  speaker  is  trying  to  "put 
over,"  but  it  also  has  certain  advantages  for 
the  speaker.  It  makes  him  condense  his  argu- 
ments to  such  a  degree  that  he  cannot  well  re- 
main ignorant  of  the  weak  spots  and  possible 
fallacies  in  his  speech  and  it  furthermore  allows 
him  to  proceed  uninterrupted  to  the  end.  His 
would-be  hecklers  must  remain  silent  until  he 
chooses  to  answer  their  questions. 


i8o 


Radio  Broadcast 


More  Injunctions  for  the  Broadcasters      poration  is  one  of 


E  NOTED  some  time  ago  the  action 
of  the  American  Society  of  Com- 
posers, Authors,  and  Publishers,  in 
calling  on  broadcasting  stations  either  to  pay 
royalties  for  broadcasting  music  or  plays  put 
out  under  the  copyright  of  its  members,  or  to 
cease  broadcasting  such  material.  We  men- 
tioned at  the  time  that  the  stand  of  the  jazz 
writers  seemed  to  be  somewhat  unreasonable 
in  that,  whatever  their  legal  rights  might  be, 
given  to  them  by  our  copyright  statutes,  most 
of  the  broadcasting  stations  were  operating  as 
experiments  only  and  were  undoubtedly  car- 
ried by  their  owners  at  a  considerable  loss. 
When  a  station  can  be  shown  to  be  on  a  paying 
basis  then  it  seems  proper  for  the  music  writers 
to  collect  as  their  share  of  the  proceeds  as  much 
as  seems  reasonable,  but  to  insist  on  large  royal- 
ties while  the  game  is  in  the  experimental  stage 
seems  very  much  like  killing  the  goose  which 
might,  some  day,  lay  golden  eggs  for  them. 

Our  ideas  along  this  line  are  confirmed  by  the 
recent  decision  of  the  management  of  WJZ, 
the  Radio  Corporation  station  at  Newark,  not 
to  broadcast  any  more  material  copyrighted  by 
the  members  of  the  complaining  society.  Thus 
it  seems  that  the  members  are  certainly  going 
to  collect  no  royalties  from  the  Radio  Corpora- 
tion and  it  seems,  furthermore,  that  this  cor- 


which  might  show 


the  very  few  companies 
a  real,  substantial  profit 


GOB  FANS  ON  THE  U.  S.  S.  MARYLAND 
Many  home-made  sets  are  turned  out  by  radio  enthusiasts  in  the  Navy.  This  par- 
ticular quartet — Arthur  Johnson,  Thomas  Frank,  Frank  June,  and  Alvin  Munne — 
are  known  as  the  "movie  gang,"  as  they  operate  the  movies  on  the  Maryland 


as  a  result  of  its  radio  activities. 

This  company  sells  a  great  many  receiving 
sets,  realizing  no  doubt  a  considerable  profit 
on  them,  furthermore  in  the  manufacture  and 
sale  of  tubes  the  average  buyer  believes  there 
must  be  a  considerable  profit  for  some  one. 
According  to  a  recent  communication  from  the 
President  of  the  Radio  Corporation,  General 
James  G.  Harbord,  one  tube  factory  alone  of 
the  Radio  Corporation  was  turning  out  5,000 
tubes  a  day  and  expected  soon  to  put  on  the 
market  10,000  tubes  a  day.  His  company  had 
been  severely  criticised  regarding  the  sudden 
disappearance  from  the  market  of  the  WD-i  i 
dry-cell  tube  of  the  Westinghouse  branch  of 
the  Radio  Corporation;  some  even  went  so  far 
as  to  accuse  the  company  of  actually  suppress- 
ing the  sale  of  these  tubes,  so  that  complete 
sets,  in  which  the  tubes  were  used,  could  be  un- 
loaded on  the  public.  In  answering  the  charge 
the  General  made  the  statement  given  above, 
that  they  would  soon  be  making  10,000 
WD-i  i's  a  day.  If  we  add  to  this  number  a 
proportionate  figure  for  those  made  by  the 
General  Electric  Company,  it  would  seem  that 
the  public  was  buying  tubes  at  the  rate  of 
more  than  a  hundred  thousand  a  week! 

Is  it?  If  so,  it  would  seem  that  this  com- 
pany might  possibly  figure  quite  a  profit 
from  its  radio  business,  but 
with  the  American  Tele- 
phone and  Telegraph  Com- 
pany, which  as  a  result  of  an 
agreement  with  the  Radio 
Corporation,  sells  practi- 
cally no  radio  receiving  sets 
or  tubes  (compared  to  the 
numbers  estimated  above), 
the  situation  is  different. 
Their  activities  in  the  radio 
broadcasting  field  have 
proved  so  far  a  rather  ex- 
pensive proposition,  yet 
they  have  come  to  some 
kind  of  an  agreement  with 
the  Society  of  Composers, 
Authors,  and  Publishers, 
and  tell  their  audience  so 
every  time  they  broadcast 
— tell  it  in  phraseology 
which  sounds  as  though  it 
had  been  specified  by  coun- 
sel for  the  musicians.  We 


The  March  of  Radio 


181 


think  the  public  is  rather 
"fed  up"  with  this  society 
and  would  enjoy  some  music 
without  being  informed  of 
the  copyrighters'  existence. 

But  it  seems  that  WEAF'S 
compromise  with  the  S.  C. 
A.  P.  only  leads  to  more  of 
the  same  kind  of  thing;  in 
their  efforts  to  give  the  pub- 
lic a  chance  to  see  how  they 
might  enjoy  a  musical  play 
via  radio  they  arranged  to 
broadcast  one  directly  from 
a  New  York  theater.  This 
scheme  at  once  called  forth 
an  announcement  from  Mr. 
Arthur  Hammerstein,  in 
behalf  of  another  society, 
this  time  the  Producing  Managers'  Associa- 
tion, in  which  it  is  declared  that  "on  behalf 
of  the  Producing  Managers'  Association  1 
wish   it   to   be  understood  that  no  music 
of  any  opera,  musical  comedy,  or  musical 
play  produced  by  these  managers  will  be  per- 
mitted to  be  broadcasted  by  radio  or  otherwise 
without  the  consent  of  the  Producing  Man- 
agers' Association.    We  give  notice  now  that 
we  shall  hold  to  strict  accountability  any  one 
who  shall  attempt  to  produce  or  broadcast  any 
of.  our  music  or  any  of  our  works    ...  in 
addition  to  which  we  shall  attempt  to  hold,  if 
it  is  found  possible,  any  violators  of  our  rights 
under  the  copyright  laws  of  the  country." 

So  it  seems  that  the  path  of  the  broadcast 
station  manager  is  beset  with  difficulties — 
wherever  he  turns  for  material  he  finds  the 
counsel  of  some  body  or  other  confronting  him, 
with  bills  for  royalties  in  one  hand  and  an  in- 
junction in  the  other.  In  the  meantime  the 
public,  the  real  beneficiaries,  get  it  all  for  noth- 
ing. 

The  Electron  and  its  Discoverer 

ANY  ONE  who  has  read  even  an  elementary 
/  \  text  on  radio  has  at  least  a  speaking 
1  V  acquaintance  with  the  electron,  the 
minute  charge  of  negative  electricity  of  which 
there  are  varying  numbers  associated  with  each 
atom,  and  to  the  arrangement  and  behavior 
of  which  is  due  the  apparently  complex  system 
of  chemical  elements.  In  what  way  does  hy- 
drogen, our  lightest  element,  differ  from  mer- 
cury, one  of  the  heaviest?    Only  in  the  number 


SIR  ARTHUR  CONAN  DOYLE  AND  LADY  DOYLE  AT  WJZ 
While  Lady  Doyle  broadcasted  her  views  on  spiritualism  from  the  Radio  Corpor- 
ation station  at  Newark,  Sir  Arthur,  known  to  everyone  as  the  creator  of  "Sherlock 
Holmes"  and  lately  come  into  public  attention  as  one  of  the  foremost  investigators 
in  the  field  of  spiritualism,  marveled  at  the  potentialities  of  radio  telephony 

and  arrangement  of  the  electrons  around  the 
positive  nucleus  of  the  atom.  The  number  of 
positive  charges  increases  as  does  the  number  of 
electrons  with  increasing  mass  of  the  atom,  but 
the  whole  behavior  and  chemical  qualities  of 
the  various  substances  seem  to  be  due  entirely 
to  the  arrangement  of  the  electrons  only.  In 
what  way  does  oxygen,  the  life-sustaining  gas, 
differ  from  chlorine,  the  death-dealing  gas? 
Only  by  the  number  and  arrangement  of  the 
electrons  in  the  atom.  Can  one  element  be 
changed  to  another?  By  shooting  off  elec- 
trons and  positive  charges  from  their  atoms  the 
radio-active  substances  are  continually  chang- 
ing from  one  chemical  element  to  another.  Sir 
Ernest  Rutherford  has  recently  shown  it  possible 
to  "hit"  a  complex  atom  with  sufficient  force 
to  knock  it  to  pieces,  the  pieces  in  this  case 
being  atoms  of  other  substances.  Besides 
being  the  active  agent  in  the  field  of  radio,  the 
electron,  and  its  arrangement  in  the  atom,  give 
us  the  various  colors  of  light,  our  X-rays,  etc. 

These  same  electrons  serve  to  pull  trolley  cars 
and  subway  trains.  The  electrons  in  the 
copper  wires  of  the  armature,  moving  with  re- 
spect to  the  electrons  in  the  field  windings  and 
magnetic  poles  of  the  motor  are  able,  by  their 
concerted  action,  to  develop  sufficient  force 
to  haul  a  long  train  at  high  speed.  It  is  this 
same  electron  which  evaporates  from  the  fila- 
ment of  the  vacuum  tube,  and  attracted  by 
the  positive  plate,  makes  possible  the  con- 
duction of  a  current  through  what  is  otherwise 
a  vacuum.  The  electrons  oscillating  up  and 
down  in  the  antenna  of  the  transmitting  sta- 
tion send  out  waves  over  their  electric  fields, 


Radio  Broadcast 


which  waves  are  able  to  set  up  corresponding 
oscillations  in  the  receiving  antenna,  and  thus 
permit  radio  communication. 

Because  of  the  important  part  played  by  the 
electron  in  radio,  it  is  fitting  to  call  your  at- 
tention to  the  visit  to  this  country  of  Sir  J. 
J.  Thompson  of  Cambridge  University,  Eng- 
land, the  discoverer  of  the  electron.  He  has 
just  finished  a  course  of  five  lectures  before  the 
Franklin  Institute  of  Philadelphia,  at  which  all 
the  lectures  had  to  do  with  some  phase  of  elec- 
tron activity.  Using  that  keen  vision  and 
imagination  with  which  every  real  scientist 
must  be  endowed,  he  called  attention  in  one 
of  his  lectures  to  the  action  of  an  electron  held 
fast  to  the  positive  nucleus  of  the  atom,  not 
able  to  move  around  as  are  the  electrons  which 
by  their  motion  give  the  electric  current. 
These  rigidly  held  electrons  have  certain  defi- 
nite arrangements  in  which  they  must  fit  to 
make  a  certain  element;  if  by  some  means  one 
of  these  electrons  is  disturbed  from  its  normal 
position  in  the  atom  it  will  at  once  endeavor  to 
fall  back  into  its  proper  position.  As  it  regains 


its  proper  place  in  the  atom  it  generally  os- 
cillates back  and  forth  about  this  position,  as 
it  "settles  down."  While  the  electron  is  thus 
oscillating  around  its  proper  place  in  the  atom 
it  sends  out  waves  on  its  electric  field  just  as 
do  the  electrons  in  the  antenna  of  the  broad- 
casting station,  but  in  the  cases  analyzed  by 
the  lecturer  the  frequency  of  the  vibrations  is 
millions  of  times  as  great  as  the  frequencies 
used  in  radio  transmission;  these  excessively 
high  frequency  waves  are  the  waves  of  ordi- 
nary light  or  in  the  case  of  those  much  shorter 
than  light  waves,  X-rays.  Thus,  says  the 
lecturer,  every  atom,  having  its  electrons  dis- 
turbed from  their  normal  positions,  acts  as  a 
transmitting  antenna,  while  they  are  settling 
back  into  place. 

Moreover,  different  atoms,  under  like  ex- 
citation, send  out  different  wavelengths  just  as 
different  transmitting  stations  do.  Thus  an 
atom  of  hydrogen,  with  vibrating  electrons, 
will  send  off  entirely  different  wavelengths 
from  those  of  an  atom  of  oxygen  or  any  other 
chemical  element.    Whereas  our  transmitting 


"THIS  IS  STATION  BG4   — OF  THE    IOIST  SIGNAL  BATTALION,  N.  Y.  N.  G. 
Located  in  Herald  Square,  New  York,  this  field  station,  type  SCR  67  A,  treats  passers-by  with  music  and  speech  from  local 
broadcasting  stations,  and  also  sends  out  recruiting  talks  on  200  meters.  The  receiving  apparatus  consists  of  detector  and 
six  stages  of  amplification,  affording  plenty  of  "kick"  for  the  loud  speaker 


The  March  of  Radio 


.83 


antennas  send  off  only  one 
wave,  however  (if  the  effect 
of  modulation  on  frequency 
is  neglected),  each  atom 
sends  off  many  waves,  but 
no  two  atoms,  of  different 
substances,  send  off  waves 
of  the  same  length,  so  that 
no  interference  is  caused 
between  the  different  ele- 
ments. To  detect  these  dif- 
ferent wavelengths  the  phy- 
sicist uses  a  spectrograph 
instead  of  a  radio  receiver; 
by  the  reading  on  his  spec- 
trograph he  can  tell  exactly 
what  "  atomic  broadcasting 
stations"  are  operating  and 
thus  recognize  the  presence 
of  different  atoms.  By  this 
means  the  physicist  knows 
what  substances  are  on  the 
hot  stars,  even  though  they 
are  millions  of  millions  of 
miles  away — a  record  for 
long  distance  reception 
never  to  be  equalled  by  the 
ordinary  broadcasting  re- 
ceiver. 

Sir  Joseph's  picture  of 
these  "  atomic  broadcasting 
stations,"  transmittingtheir 
characteristic  waves  over 
distances  inconceivably 
great  compared  to  terrestrial 
distances,  with  wavelengths 
so  faithfully  maintained  at 
the  values  assigned  to  them 
by  Nature  that  our  best 
measuring  instruments, 
thousands  of  times  as  precise 
as  any  radio  measuring  in- 
struments, cannot  even  detect  any  departure 
whatever,  cannot  but  serve  as  a  stimulus  and 
inspiration  to  our  research  workers,  ever  seek- 
ing to  expand  and  improve  the  radio  art. 

Wavelength  or  Frequency? 

A CHANGE  in  radio  nomenclature  is  now 
being  advocated  by  radio  engineers 
and  others  interested  in  radio  develop- 
ment, which,  if  adopted,  will  put  into  the  dis- 
card the  familiar  term  "wavelength."  In  place 
of  this  term,  which  really  serves  to  identify  the 


SIR  JOSEPH  THOMSON,  DISCOVERER  OF  THE  ELECTRON 

On  his  recent  visit  to  this  country,  he  witnessed  the  progress  which  American  en- 
gineers had  made  with  his  theory  of  electrons,  upon  which  the  present  development 
of  long-distance  radio  communication  is  largely  based.    His  investigations  along 
this  line  took  Sir  Joseph  Thomson  ten  years 


number  of  cycles  per  second  of  the  alternating 
current  at  the  transmitting  station,  will  be 
substituted  the  more  logical  and  reasonable 
word,  frequency,  measured  in  cycles  per  second. 

Radio  is  nothing  but  a  special  branch  of  com- 
munication engineering,  itself  an  important 
sub-division  of  the  general  field  of  electrical  en- 
gineering; and  as  such  its  language  must  natur- 
ally conform  to  that  of  electrical  engineering 
as  a  whole.  Certain  specific  features  of  radio 
communication,  being  peculiar  to  radio,  and 
used  only  by  radio  engineers  and  experimen- 
ters, may  be  named  in  accordance  with  the 


Radio  Broadcast 


LISTENING  TO  AN  ADDRESS  BY  GOVERNOR  PINCHOT  IN  ORRSTOWN,  PA. 
In  this  rural  community,  young  and  old  gather  in  the  little  school-house  to  hear  the  broadcasts  received  on  the  set  owned 
and  operated  by  Miss  Hannah  H.  Kieffer,  Director  of  Rural  Education  in  the  Cumberland  Valley.    This  receiver,  with 
the  power  amplifier,  is  used  in  twelve  different  community  centres,  and  has  brought  in  stations  from  Iowa  to  Texas  and 

from  Canada  to  Cuba 


judgment  of  those  responsible  for  coining  the 
new  words  and  expressions,  but  in  so  far  as 
radio  uses  ideas  and  methods  in  use  in  other 
branches  of  engineering,  which  have  already 
been  named  and  defined,  the  nomenclature 
must  be  consistent  with  that  already  adopted. 

It  is  very  easy  to  see  how  radio  has  de- 
veloped its  own  ianguage;  when  Marconi  and 
the  other  pioneers  started  to  talk  and  write 
about  their  work  it  was  not  at  all  evident  that 
they  were  engaged  in  a  natural  sub-division 
of  engineering.  It  undoubtedly  seemed  to 
them  an  entirely  new  art  and  as  such  to  demand 
new  words  and  expressions.  But  as  we  have 
studied  and  experimented  in  radio,  discovered 
its  laws,  and  found  them  to  be  in  agreement 
with  those  of  other  branches  of  electrical  en- 
gineering, it  has  become  ever  more  evident  that 
here  is  simply  an  addition  to  the  general  field 
of  communication  engineering  and  as  such  it 
must  incline  in  its  language  toward  that  al- 
ready in  vogue  among  communication  en- 
gineers. 

That  the  language  of  radio  has  changed  to  a 
great  extent  even  during  its  short  life  of  a 
quarter  of  a  century  becomes  evident  to  one 


reading  the  early  writings.  We  wonder  how 
many  of  our  readers  know  what  a  "jigger"  is 
and  does;  to  Marconi  it  was  an  extremely  im- 
portant piece  of  apparatus.  Does  any  one 
nowadays  use  one  of  Marconi's  "  X-stoppers"? 
Fifteen  years  ago,  Fleming  invented  the  very 
useful  "cymometer",  yet  we  do  not  often  hear 
it  mentioned.  Fessenden,  in  his  early  and 
important  contributions  to  the  art,  employed 
a  "barretter"  which  he  found  very  sensitive 
and  reliable,  compared  to  other  similar  appara- 
tus, and  Count  von  Arco's  "syntonizer" 
seemed  like  a  piece  of  radio  equipment  des- 
tined to  become  known  to  every  one.  We 
suspect  that  a  large  proportion  of  our  readers 
hardly  know  what  a  coherer  is,  yet  it  was  but  a 
few  years  ago  that  every  radio  worker  was  en- 
deavoring to  improve  it.  The  radio  nomen- 
clature of  to-day  does  not  know  these  words  of 
only  a  few  years  ago,  so  it  is  not  at  all  unlikely 
that  many  of  our  present  terms  may  likewise 
disappear  in  a  few  more  years. 

One  of  the  most  important  characteristics  of 
a  radio  signal  is  its  frequency,  that  is,  the  fre- 
quency of  the  alternating  current  in  the  an- 
tenna of  the  transmitting  station.    In  the 


The  March  of  Radio 


.85 


early  days  this  was  known  only  approximately, 
but  it  was  always  many  hundreds  of  thousands 
of  cycles  per  second,  if  not  several  millions. 
As  the  early  experimenters,  familiar  with  the 
electromagnetic  theory  of  Clerk  Maxwell,  and 
the  experimental  verification  of  the  same  by 
Heinrich  Hertz,  pictured  the  electromagnetic 
waves  shaken  off  from  their  antennas  and 
traveling  away  in  all  directions  with  the  veloc- 
ity of  light,  it  was  natural  for  them  to  think  of 
wavelengths,  as  well  as  frequency,  and  as  the 
wavelengths,  in  meters,  were  generally  a  few 
hundreds  only,  and  the  frequency  hundreds  of 
thousands  or  more,  it  naturally  became  the 
practice  to  speak  of  wavelength  in  meters 
rather  than  of  frequency  in  cycles  per  second. 

As  long  distance  radio  developed,  and  the 
longer  waves  proved  more  suitable  than  the 
shorter  ones,  the  frequencies  used  became 
lower  and  lower;  thus  a  15,000-meter  wave 
used  for  transatlantic  communication,  requires 
in  the  antenna  a  current  of  only  20,000  cycles 
per  second  and  this  is  getting  well  down  to  the 
frequencies  used  every  day  by  the  telephone 
engineer.  It  seems  then,  that  from  this  view- 
point alone,  it  would  be  advisable  to  conform 
to  engineering  usage  and  speak  of  cycles  instead 
of  wavelength,  unless  some  serious  disad- 
vantage should  arise  therefrom.  Instead  of 
being  disadvantageous, 
however,  it  will  be  pointed 
out  later  that  a  marked  ad- 
vantage accrues  to  the  radio 
engineer  by  thinking  in 
terms  of  cycles  instead  of 
wavelength. 

It  will  be  remarked  that 
the  frequencies  of  the  cur- 
rents used  in  broadcasting 
are  always  several  hundred 
thousand  per  second,  so  that 
apparently  inconveniently 
large  numbers  would  have 
to  be  used,  such  as  seven 
hundred  and  fifty  thousand 
cycles  per  second,  which  is 
evidently  more  troublesome 
than  to  say  a  wavelength  of 
four  hundred  meters.  But 
the  term  seven  hundred  and 
fifty  thousand  cycles  per 
second  will  be  abbreviated 
to  seven  hundred  and  fifty 
kilo-cycles;  electrical  engi- 
neers have  found  it  unnec- 


essary to  retain  the  "per  second"  part  of 
the  term  as  this  is  always  understood,  and  the 
idea  of  "thousand"  is  obtained  from  the  prefix 
"kilo",  The  engineer  interested  in  transmission 
lines  always  speaks  of  "so  many  kilo-volts"  in- 
stead of  speaking  of  thousands  of  volts.  So 
the  four  hundred  meter  v/ave  signal  may  soon 
become  a  seven  hundred  and  fifty  kilo-cycle 
signal  and  the  three  hundred  meter  wave  a  one 
thousand  kilo-cycle  signal,  etc. 

The  advantage  of  speaking  in  kilo-cycles, 
besides  putting  radio  in  conformity  with  the 
rest  of  electrical  engineering  nomenclature, 
arises  from  the  ideas  of  "wave  bands"  used  in 
radio  telephony.  There  the  kilo-cycle  shows 
itself  much  more  useful  in  conveying  informa- 
tion than  the  term  wavelength.  For  the  or- 
dinary radio  telephone  channel  there  is  re- 
quired a  band  of  frequencies  about  ten  thou- 
sand cycles  wide,  on  each  side  of  the  carrier 
frequency.  Thus  a  four  hundred  meter  broad- 
casting station,  using  the  ordinary  method  of 
modulation,  requires  the  exclusive  use  of  fre- 
quencies from  seven  hundred  forty  to  seven 
hundred  sixty  kilo-cycles,  the  carrier  frequency 
being  seven  hundred  fifty  kilo-cycles.  A  neigh- 
boring station,  sending  with  a  carrier  of  seven 
hundred  twenty-five  kilo-cycles,  would  require 
for  its  exclusive  use  all  frequencies  between 


AN   ENGLISHMAN  TELLS  THE  BEAR  FACTS 

This  diminutive  British  subject  is  rebroadcasting  to 
his  attentive  companion  the  story  of  the  Three  Bears 


Radio  Broadcast 


seven  hundred  fifteen  and  seven  hundred 
thirty-five  kilo-cycles.  With -a  good  receiving 
set  there  would  be  no  interference  between 
these  two  stations,  although  it  would  not  be 
advisable  to  use  carrier  frequencies  so  close 
together  for  neighboring  stations,  because  the 
crystal  sets,  of  which  there  are  a  good  many  in 
use,  would  be  bothered  by  interference. 

Now  this  frequency  band,  carrier  frequency 
plus  and  minus  ten  thousand,  is  required  no 
matter  what  the  wavelength  of  the  carrier  may  he, 
so  that  in  calculating  the  number  of  radio  tele- 
phone channels  available  in  a  certain  wave- 
length range  the  engineer  has  to  change  the 
wavelengths  over  to  frequencies  anyway. 
Moreover  when  this  is  done  it  is  much  easier  to 
see  at  once  the  number  of  channels  available 
in  a  given  assigned  range  than  it  is  if  the  same 
range  is  given  in  wavelengths.  Thus  if  broad- 
casting is  given  a  wavelength  range  of  from  220 
meters  to  550  meters,  and  amateurs  are  assigned 
the  1 50  to  220  meter  band,  it  seems  as  though  they 


were  getting  squeezed  into  a  pretty  narrow  region, 
but  this  is  really  not  the  case.  The  assignment 
would  give  to  broadcasting  from  545  kilo- 
cycles to  1360  kilo-cycles,  a  band  of  815  kilo- 
cycles in  which  about  twenty  channels  are 
available.  The  assignment  to  the  amateur, 
although  apparently  much  narrower  than  this 
actually  gives  to  him  a  frequency  band  640 
kilo-cycles  wide,  almost  as  many  channels  thus 
being  available  to  the  amateur  as  to  the  wider 
wavelength  assignment  for  broadcasting.  This 
increase  in  the  number  of  channels  in  a  given 
wavelength  band  as  the  band  moves  into  the 
shorter  waves  is  not  apparent  when  speaking 
in  terms  of  wavelength,  but  appears  at  once 
when  the  frequency  of  the  current  is  used  to 
designate  the  signal  instead  of  the  wavelength. 

From  the  foregoing  analysis,  the  advantage 
of  kilo-cycles  over  wavelength  is  evident  and 
when  it  is  further  remembered  that  all  the 
instruments  used  for  making  radio  measure- 
ments are  really  frequency-measuring  instru- 


The  March  of  Radio 


.87 


PUBLIC  SCHOOL  STUDENTS  BROADCASTING  THEIR  PRIZE  COMPOSITIONS 
Violet  Miller,  age  12,  of  School  No.  77,  Ridgewood,  Long  Island,  is  "on"  at  WHN,  while  other  budding  writers  await 
their  turn.    School  No.  77  is  perhaps  the  first  to  hold  a  children's  radio  forum,  an  institution  which  not  only  stimulates 
a  great  interest  in  the  writing  of  compositions,  but  gives  the  children  excellent  practice  in  public-speaking 


ments  rather  than  wavelength  meters  as  ap- 
pears from  the  name  "wave  meter",  and  when 
it  is  further  appreciated  that  waves  do  not  have 
their  specified  length  except  when  they  are 
traveling  through  free  space  where  there  is  no 
absorption,  the  decision  of  the  radio  engineers 
to  use  kilo-cycles  instead  of  wavelength  is  seen 
to  be  reasonable  and  justifiable.  Standard 
works  on  radio,  and  technical  radio  magazines 
will,  for  some  time  at  least,  print  the  kilo- 
cycles per  second  and  wavelength  in  meters 
side  by  side.  So  it  is  well  to  get  yourself  accus- 
tomed to  thinking  of  a  station  in  terms  of  its 
kilo-cycles,  obtained  by  dividing  three  hundred 
thousand  by  the  wavelength  in  meters. 

The  Possibility  of  Re-Broadcasting 

IT  IS  evident  to  any  one  who  thinks  much 
about  the  question  that  in  the  final  solu- 
tion of  the  broadcasting  problem  a  given 
program  must  be  made  to  reach  as  large  an 
audience  as  possible;  as  the  programs  of  the 


broadcasting  stations  improve,  this  fact  will 
become  increasingly  apparent.  For  example, 
if  an  opera  is  being  broadcasted  from  the 
Metropolitan  Opera  House  in  New  York,  the 
artists  may  be  the  finest  in  the  world;  why  then 
should  people  in  other  sections  of  the  country 
who  enjoy  opera,  have  to  listen  to  some  mediocre 
program  from  a  local  station?  Of  course, 
entirely  apart  from  radio,  this  is  actually  the 
case  to-day;  we  can't  all  go  to  the  best  opera 
and  so  we  have  to  content  ourselves  with  some- 
thing less  expensive  and  less  artistic.  But 
right  here  lies  the  great  promise  of  radio — it 
need  cost  but  little  more  to  broadcast  to  a  mil- 
lion listeners  than  to  a  thousand,  so  that  the 
very  best  programmes  should  be  available  to 
every  one. 

Some  enthusiasts  will  of  course  say,  "Why 
worry  about  the  situation?  We  listen  to  New 
York  programs  every  night  even  though  we 
are  more  than  a  thousand  miles  away."  But  for 
every  such  listener  there  are  a  hundred  others, 
potential  or  actual  listeners,  who  do  not  re- 


Radio  Broadcast 


SOLDERING  TRANSFORMER  LEADS — A  DELICATE  JOB 

There  are  more  than  one  hundred  distinct  parts  used  in  each  of  these  audio-fre- 
quency transformers.  No.  40  enameled  wire,  thinner  than  a  human  hair,  is  used 
and  the  task  of  making  uniformly  neat  soldering  jobs  with  wire  as  fine  as 
this  would  be  difficult  for  most  people.    Not  so  for  Miss  Gay  Garrity,  however 


ceive  over  such  distances.  The  majority  will 
probably  always  be  in  this  class.  Expensive 
receiving  sets,  great  selectivity  and  difficult 
manipulation,  are  not  the  factors  which  make 
for  the  popularization  of  radio,  and  most  of 
these  are  required  for  reliable  long  distance 
reception. 

The  question  then  arises,  How  is  the  multi- 
tude to  get  in  contact  with  the  good  stations? 
Two  possibilities  are  being  tried  out  and  both 
of  them  are  likely  to  be  in  service  before  long. 
The  program  can  be  relayed  to  the  various 
broadcasting  stations  located  throughout  the 
country  by  either  radio  or  wire.  Station 
KDKA  has  for  some  time  past  been  sending 
out  its  programs  for  re-broadcasting  in  other 
cities,  the  transmission  between  the  two  sta- 
tions being  carried  out  on  a  100-meter  wave. 
This  100-meter  signal  is  used  to  actuate  the 
modulator  of  the  second  broadcasting  station, 
in  Cleveland  for  example,  which  then  sends 
out  the  program  on  360  meters.  This  scheme 
requires  the  very  best  kind  of  receiving  set 
at  the  second  station  in  order  that  the  signal 
may  not  be  unreasonably  distorted  while 
being  received  and  amplified  for  its  second 
transmission. 

The  second  scheme,  which  seems  to  us  more 
reasonable,  less  likely  to  either  receive  or  give 
interference,  is  to  send  the  signal  from  the  first 


broadcasting  station  to  the 
others  in  the  form  of  audio- 
frequency currents,  over 
wires.  This  will  undoubt- 
edly be  the  method  of 
attack  of  the  American 
Telephone  and  Telegraph 
Company  as  their  engi- 
neers are  experts  on  speech 
transmission  over  wires, 
and  they  can  carry  speech 
currents  over  wires  almost 
any  distance,  with  as  little 
distortion  as  the  case  may 
demand.  They  understand 
the  factors  involved  suf- 
ficiently well  to  predict, 
even  before  a  line  is  put 
into  operation,  how  good 
the  speech  will  be;  if  the 
amount  of  permissible  dis- 
tortion is  specified,  they 
can  design  a  line  and  ter- 
minal apparatus  which  will 
meet  the  specifications. 
In  other  words  here  is  a  problem  which  can 
be  solved  any  time  the  money  is  available: 
Telephone  transmission  is  frequently  very 
poor,  as  every  one  knows,  but  the  ordinary 
transmission  does  not  show,  by  any  means, 
what  the  engineering  staff  could  do  if  occa- 
sion demanded  better,  and  if  the  funds  were 
available. 

In  this  scheme,  therefore,  all  broadcasting 
stations  will  be  connected  to  a  network  of  tele- 
phone lines  and  cables,  and  the  same  audio- 
frequency signal  will  modulate  all  the  radio 
transmitters  simultaneously.  This  scheme  does 
not  use  up  any  extra  ether  channels  and  should 
be  much  less  subject  to  atmospheric  and  other 
disturbances  than  is  the  radio  transmission. 
Moreover,  disturbances  on  a  wire  line  can  gen- 
erally be  eliminated  by  certain  engineering 
tricks,  if  the  importance  of  the  transmission 
justifies  the  expense,  whereas  but  little  prog- 
ress has  been  made  in  eliminating  static  dis- 
turbances from  the  ether  channels. 

It  seems  to  us  that  the  future  of  broadcasting 
is  intimately  connected  with  the  establishment 
of  a  wire  network  covering  the  country  and 
connected  to  the  best  broadcasting  station  in 
a  given  locality,  this  wire  network  to  be  of  the 
highest  quality  that  the  telephone  engineer — 
who  has  had  years  of  experience  in  this  sort 
of  thing — knows  how  to  build. 


The  March  of  Radio 


Weather  Forecasts 

WITH  the  idea  of  increasing  the  util- 
ity of  the  Weather  Bureau  service, 
a  new  broadcasting  schedule  has 
been  recently  put  into  effect.  Every  day  of  the 
year  there  will  be  sent  out  from  the  Arlington 
Naval  Radio  Station  (NAA),  on  a  wavelength 
of  710  meters,  radio  telephone  weather  forecasts 
and  warnings  for  all  the  Eastern  part  of  the 
United  States. 

In  addition  to  these  services,  at  10.05  A.  M. 
and  10.05  P-  M.,  an  additional  forecast  will  be 
sent  out,  at  3.45  P.  M.,  daily  except  Sundays 
and  holidays,  and  also  on  Wednesdays  (at  7.45 
P.  M.)  during  the  growing  season,  March  15  to 
Nov.  30,  advice  will  be  sent  out  for  farmers  and 
others  interested,  summing  up  the  effect  of  the 
weather  for  the  past  week  on  the  progress  of 
the  crops. 

A  feature  of  this  service  which  provides  for 
dissemination  of  the  weather  forecasts  imme- 
diately after  they  are  issued,  is  that  the  an- 
nouncements are  made  directly  from  the 
Weather  Bureau  Office  in  Washington,  which 
is  connected  by  telephone  with  the  transmitting 
apparatus  located  at  Arlington.  The  bulletin 
giving  us  this  information  requests  that  lis- 
teners send  in  suggestions  to  the  Chief  of  the 
Weather  Bureau,  Washington,  D.  C.  stating 
which  service  is  of  most  use  to  them,  how  the 
transmission  is  received,  as  well  as  any  sug- 
gestions regarding  the  possible  improvement 
in  this  new  branch  of  government  activity. 

An  Old  Radio  Company  Changes  Hands 

ACCORDING  to  a  recent  announcement 
of  Mr.  Charles  Gilbert,  President  of 
L  the  De  Forest  Radio  Telephone  and 
Telegraph  Company,  the  control  of  this  com- 
pany has  passed  into  the  hands  of  certain  auto- 
mobile manufacturers,  including  E.  T.  Jewett, 
of  the  Paige  Motor  Car  Company,  some  of  the 
financiers  having  large  interests  in  the  auto- 
mobile industry,  and  William  H.  Priess,  the 
latter  having  a  patent  on  a  certain  reflex  circuit 
at  present  used  in  some  of  the  De  Forest  sets. 
The  re-organization  will  place  at  the  disposal 
of  the  company  sufficient  funds  to  permit  that 
expansion  which  the  ever-increasing  interest 
in  radio  receiving  seems  to  warrant.  Dr.  De 
Forest  has  been  retained  by  the  new  company 
as  consulting  engineer,  his  services  being  en- 
gaged for  a  period  of  ten  years  together  with 


rights  relating  to  patents  he  may  obtain  during 
that  period. 

The  De  Forest  company  is  anticipating  a 
considerable  increase  in  its  tube  plant.  Ac- 
cording to  Mr.  Gilbert,  the  present  plant  has 
a  capacity  of  1200  tubes  a  day,  but  it  is  ex- 
pected to  increase  the  number  of  men  em- 
ployed there  from  300  to  600  and  so  increase 
the  tube  output  to  2400  a  day. 

Certain  subsidiary  De  Forest  companies, 
notably  those  primarily  interested  in  research 
and  development,  will  continue  their  work  as  at 
present,  but  the  result  of  their  work  will  un- 
doubtedly be  placed  at  the  disposal  of  the 
larger  company.  The  phono-film,  De  Forest's 
invention  in  the  field  of  talking  movies,  is  not 
affected  by  the  transfer  as  this  development  has 
already  been  taken  over  by  a  company  formed 
especially  for  the  purpose.  Still  another  De 
Forest  enterprise,  the  De  Forest  Patent  Hold- 
ing Corporation,  is  exempt  from  the  new  agree- 
ment, its  control  remaining  as  at  present. 

An  Opportunity 

PEOPLE  away  on  a  summer  vacation 
are  especially  susceptible  to  new  ideas, 
their  old  prejudices  have  been  left  at 
home  and  they  are  quite  ready  to  try  anything 
that  looks  interesting.  They  are  easily  "sold," 
as  witness  the  high  hotel  rates  for  mediocre  ac- 
commodations and  the  excessive  prices  often 
charged  at  the  novelty  stores  with  which  the 
average  summer  resort  is  so  richly  endowed. 

Now,  if  the  Radio  Dealers'  Association  would 
put  into  the  summer  hotel  one  of  their  best 
receiving  sets,  with  the  best  loud  speaker  ob- 
tainable, we  believe  many  people  would  become 
radio  converts.  Many  times  the  evenings  at 
the  smaller  resorts  are  quite  dull,  and  we  are 
sure  that  a  good  receiving  set  would  be  an  at- 
traction which  could  do  real  service.  It  would 
pay  the  dealers  to  install  these  sets  in  the  hotel 
for  nothing,  and  maintain  them  for  nothing; 
the  people  at  the  resorts  are  the  kind  that 
have  sufficient  money  to  invest  in  a  good  re- 
ceiving set,  and  they  will  be  excellent  "pros- 
pects" if  the  demonstrations  are  good  enough 
to  create  the  right  impression. 

There  are  receiving  sets  and  loud  speakers 
which  reproduce  music  better  than  the  best 
phonograph. 

This  looks  like  a  real  opportunity  to  increase 
the  popularity  of  radio,  and  we  hope  the  dealers 
will  seize  it.  J.  H.  M. 


Making  Radio  Your  Business 


By  CARL  DREHER 

Engineer,  Radio  Corporation  of  America 


M  FTER  extended  observation    I  am 
i\     convinced  that  the  rising  generation 
/  %    intends  to  go  into  professional  radio 
I      \  en  masse.    Not  only  the  rising  gen- 
^       ^  eration,  but  also  many  of  the  gener- 
ation long  since  risen.    What  are  the  oppor- 
tunities, they  want  to  know?    What  sort  of 
jobs  are  to  be  had  or  will  be  available,  what 
qualifications  are  necessary,   what  personal 
qualities  are  desirable?    Can  one  become  rich 
as  fast  as  Coal-Oil  Johnny,  or  richer  and  faster? 
Shall  we  train  little  Oswald  to  be  a  radio  en- 
gineer, or  do  you  think  he  will  be  happier  as  a 
lard  salesman?    Will  Mr.  X.  who  lost  every- 
thing he  had  during  the  late  radio  boom,  ever 
regain  it?    Was  it  his  fault  that  he  went  under, 
or  was  it  Fate?    Do  all  wireless  operators  rise 
to  $io,ooo-a-year  jobs?    And  so  on. 

Not  all  of  these  questions  can  be  readily  an- 
swered, but  it  may  be  useful  to  attempt  the  for- 
mulation of  a  list,  more  or  less  complete,  of  the 
various  positions  which  the  individual  vaguely 
known  as  a  "  radio  man  "  may  fill,  and  the  par- 
ticular type  of  character  which  fits  best  into 
each  place.  In  some  cases  this  is  a  matter  of 
opinion,  and  while  the  writer's  ideas  are  based 
on  acquaintance  with  and  observation  of  a 
considerable  number  of  radio  professionals  in 
active  practice,  he  does  not  wish  to  lay  down 
dogmatic  rules,  nor  to  have  his  conclusions 
swallowed  uncritically.  It  is  obvious,  how- 
ever, that  the  engineer  in  charge  of  a  broad- 
casting station,  for  example,  should  know  a 
scherzo  from  a  Maltese  cat,  possess  some  social 
ability,  and  not  chew  tobacco,  while  the  wire- 
less operator  of  an  oil  tanker  need  not  shave 
more  than  once  in  a  fortnight,  need  know 
nothing  about  music,  and  may  chew  tobacco 
or  even  loco  weed  without  hindrance.  A  par- 
ticular variety  of  character  make-up,  that  is, 
is  required  for  each  of  these  positions,  in  ad- 
dition to  the  difference  in  technical  qualifica- 
tions. 

A  very  common  means  of  breaking  into  pro- 
fessional radio  is  by  the  operating  route.  Pro- 
fessional operators  are  recruited  largely  from 
the  ranks  of  the  amateurs.  Many  boys  of 
high  school  age  learn  the  rudiments  of  radio 


theory  at  home,  running  their  own  sets,  then 
go  to  a  school  for  a  period  of  about  six  months, 
to  be  taught  the  somewhat  different  methods 
of  handling  commercial  equipment  and  dis- 
patching traffic.  If  they  qualify  for  the  second 
grade  operator's  license  they  may  then  be  as- 
signed to  a  ship  as  junior  operators.  This  is  a 
sort  of  apprenticeship,  for  while  the  second 
operator  stands  regular  watches,  in  case  of 
emergency,  or  if  he  gets  into  trouble,  he  can 
always  rout  out  the  senior  radio  man,  provided 
the  latter  is  of  a  not  too  irascible  temper.  In 
time,  usually  about  a  year  after  he  thinks  that 
he  knows  more  than  the  senior  operator,  the 
junior  may  be  promoted  to  the  first  position  on 
board  some  other  ship,  and  then,  after  some 
years  more  of  marine  service,  he  may  be  in 
line  for  a  job  at  a  land  station. 

ABOUT  GOING  TO  SEA 

THE  advantages  of  the  marine  operator's 
life  are  that  he  gets  to  see  the  world  and 
the  ways  of  other  people  than  those  of  his  na- 
tive Main  Street;  that  he  can  save  considerable 
money  if  he  is  so  inclined;  that  his  migratory 
existence  usually  preserves  him  from  getting 
married  too  early,  and  that  he  has  an  oppor- 
tunity to  study  and  to  learn  the  insides,  not 
only  of  ship-to-shore  radio,  but  the  shipping 
industry  in  general.  In  regard  to  saving 
money,  the  average  senior  operator  is  paid  in 
the  neighborhood  of  $100  a  month  at  the  pres- 
ent time,  and  a  junior  about  S70,  plus  his 
lodging  and  food  aboard  ship.  It  is  not  at  all 
difficult  for  an  operator  to  lay  away  ^40-^70  a 
month,  if  he  is  not  too  much  attracted  by  the 
bright  lights  on  his  periods  of  shore  leave, 
and  thus  in  the  course  of  a  few  years  he  may 
amass  a  capital  of  several  thousand  dollars  and 
be  in  a  position  to  start  a  small  business  on 
shore.  The  disadvantages  are  that  the  hours 
are  irregular  and  involve  night  work,  and  some 
men  find  this  schedule  unhygienic,  although  the 
health  of  the  general  run  of  ship  operators  is 
probably  as  good  as  that  of  men  in  other  voca- 
tions; and  that  in  many  cases  the  man  tends  to 
become  lazy  and  to  lose  his  ambition.  Ship 
jobs  are  of  all  kinds — on  the  large  transoceanic 


Making  Radio  Your  Business 


liners  the  telegraphers  work  almost  as  hard  as 
the  Morse  operators  on  bonus  wires  ashore,  and 
in  fact  high  speed  automatic  equipment  is 
being  installed  on  some  vessels  in  this  class. 
On  other  ships  the  work  is  very  slack;  only 
a  few  messages  a  day  are  handled,  and  if 
the  operators  are  naturally  inclined  to  fol- 
low the  line  of  least  resistance,  such  posi- 
tions aredemoralizing. 

While  some  of  the 
foremost  executives  in 
radio  to-day  received 
their  start  as  opera- 
tors, it  is  also  true  that 
a  man  may  be  indus- 
trious, and  be  an  ex- 
traordinary operator, 
and  yet  show  little  ap- 
titude for  any  other 
position.  In  such  a 
case  he  frequently  gets 
into  high-power  re- 
ception, where  the 
particular  coordina- 
tion of  ear.  eye,  and 
hand  at  which  he  has 
become  adept  will 
stand  him  in  good 
stead.  The  pay  of  such 
men  runs  about  level 
with  that  of  skilled 
landline  telegraphers 
in  brokers'  offices  and 
the  like,  about  $180  a 
month,  with  often  a 
chance  to  earn  more 

by  working  overtime.  This  is  for  really  fast 
men  who  can  take  35  words  a  minute.  Con- 
trary to  the  general  impression,  a  man  may 
be  an  excellent  operator  and  know  little  of 
the  mechanics  or  theory  of  radio.  As  in  the 
case  of  other  fields,  the  work  is  tending  to 
become  more  and  more  specialized,  and  just 
as  many  engineers  scarcely  know  the  Conti- 
nental code,  so  operators  may  be  found  who 
have  less  acquaintance  with  the  engineering  as- 
pects of  the  art  than  some  of  the  enthusiastic 
laymen  in  the  broadcast  reception  ranks. 

A  skilled  operator  who  shows  comprehension 
of  the  technique  of  handling  traffic — routing  of 
messages,  proper  coordination  with  foreign 
stations,  and  the  like,  and  who  displays  some 
executive  ability,  may  graduate  into  the  ranks 
of  supervisors,  chief  operators,  and  super- 
intendents of  stations.    In  these  positions  a 


Summer  is  with  us  again.  Schools  and  col- 
leges are  "letting  out"  until  next  September; 
and  many  a  young  fellow  is  looking  for  a  job 
of  a  kind  that  will  be  at  once  a  business  train- 
ing, a  vacation  (at  least  in  the  sense  of  being  a 
change  from  the  winter's  work),  and  a  source 
of  income.  Comparatively  few  young  men 
have  a  strong  natural  inclination  toward  one 
particular  kind  of  work.  Often,  it  is  by  the 
merest  chance — a  scrap  of  information  that 
appeals  to  the  imagination,  a  lack  of  interest 
in  certain  other  fields,  or  some  unaccountable 
and  illogical  prejudice — which  lands  a  fellow 
in  a  job  in  which  he  is  destined  to  make  a  dis- 
tinct success. 

A  boy's  hobby  often  leads  to  a  man's  busi- 
ness. How  many  young  radio  enthusiasts  of 
to-day  will  be  in  one  way  or  another  connected 
with  the  radio  game  when  they  grow  older? 
Thousands — that  is  certain.  For  them,  and 
for  other  thousands  who  may  have  only  a 
vague  idea,  or  none  at  all,  that  their  life  work 
may  be  concerned  with  radio,  this  article  of 
Mr.  Dreher's  will  have  a  strong  appeal. — The 
Editor. 


man  must  possess  technical  qualifications 
enough  to  enable  him  to  cooperate  with  engi- 
neers, he  must  know  how  to  keep  traffic  moving 
as  fast  as  is  consistent  with  accuracy  under 
various  conditions,  and  he  must  be  familiar 
with  the  ordinary  methods  and  principles  of 
business  practice.  All  this  requires  ability 
which  comes  only  with  years  of  observation 

and  experience.  Not 
only  is  it  necessary  to 
know  radio,  but  ex- 
perience in  other  lines 
of  communication  is 
also  very  desirable. 
The  majority  of  the 
traffic  executives  in 
radio  to-day  are  ex- 
cable  and  ex-telegraph 
men.  They  know  how 
to  cooperate  with  the 
older  methods  of  com- 
munication, and  how 
to  compete  with  them 
when  expedient.  They 
are  not  likely  to  over- 
look tricks  of  the  wire 
trade  which  may  be 
adapted  readily  to 
ether  communication. 
The  development  of 
radio  has  in  many 
respects  paralleled 
the  growth  of  wire 
telegraphy,  in,  for  ex- 
ample, high-speed  au- 
tomatic methods,  and 
the  history  of  radio  invention  is  in  part  a 
process  of  adaption  from  cable  and  wire  tech- 
nique with,  of  course,  many  innovations  and 
novel  expedients.  Likewise  the  men  at  the 
very  top  of  radio  communication,  particularly 
in  its  high-power  international  aspects,  are 
largely  former  executives  of  wire  telegraph 
companies.  Accordingly,  if  a  man  wants  to 
become  a  real  expert  in  radio  telegraphy,  it 
might  be  good  advice  to  tell  him  to  start  with 
a  cable  company,  just  as  a  few  years  of  tele- 
phone experience  are  a  sizable  asset  for  a 
specialist  in  radio  broadcasting. 

THE  TRAFFIC  MAN 

THE  traffic  or  operating  man  must  always 
be  prepared  to  think  and  act  quickly,  as 
an  inherent  requisite  in  his  field.  He  has 
under  his  charge  expensive  machinery  and  elab- 


192 


Radio  Broadcast 


GEORGE    LEWIS — ONE  OF  THE   "  OLD-TIMERS " 

He  has  been  actively  interested  in  radio  since  1908 — 
possesses  the  first  commercial  operator's  license  issued 
by  the  U.  S. — was  in  charge  of  field  radio  design  for  the 
Signal  Corps  in  1910 — designed  the  first  high-power 
military  radio  tractor  and  the  first  tuned-circuit  trans- 
mitter, making  air-craft  transmission  possible — was  in 
charge  of  radio  design  division  at  the  Navy  Department 
during  the  War — organized  and  was  first  executive  secre- 
tary of  the  National  Radio  Chamber  of  Commerce — and 
is  at  present  with  the  Crosley  Mfg.  Co.  as  assistant  to 
Mr.  Crosley.  He  has  traveled  widely  in  this  country, 
Europe,  and  the  Orient,  and  is  well  known  in  radio  circles 
here  and  abroad.  As  a  recreation  from  work,  Mr.  Lewis 
writes  poetry,  plays  golf,  and  enlarges  his  collection  of 
artistic  camera  studies  -  " 

orate  circuits  which  must  be  utilized  to  the 
fullest  possible  extent.  The  case  is  the  same 
whether  the  operating  man  has  charge  of  a 
broadcasting  station,  or  is  pounding  the  key  in 
a  ship's  cabin,  or  has  charge  of  a  transoceanic 
station.  In  the  broadcasting  station  one  can- 
not afford  to  keep  either  the  performers  or  the 
radio  audience  waiting.  Marine  radio  con- 
ditions in  congested  districts  are  like  the  New 
York  subways  during  the  rush  hour.  There 
are  always  four  or  five  ships  lined  up  waiting 
to  unload  their  messages.  The  land  station 
gives  its  "Go  ahead"  signal  to  a  ship,  and  the 
ship  is  expected  to  be  there  with  its  answer 
with  a  speed  somewhat  exceeding  that  of  a 
faculty  procession.  In  a  transoceanic  station 
the  payroll  and  the  investment  are  very  high 


and  delays  eat  up  the  profits.  The  design  and 
research  people  know  occasional  periods  of 
leisure,  but  the  operating  man's  job  is  often  an 
uninterrupted  rush;  at  least  his  ability  to  hold 
it  is  dependent  on  his  ability  to  get  things  done 
fast  at  certain  times.  Thus  if  one  has  as- 
pirations in  the  way  of  making  a  living. in  the 
radio  field  and  one's  natural  tendency  is  to 
work  slowly,  however  thoroughly  and  de- 
pendably, the  best  thing  is  to  keep  away  from 
the  operating  end  of  the  game. 

Of  course  a  man  who  gets  dizzy  on  the  deck 
of  an  auto  bus  may  develop  into  a  successful 
steeplejack — but  the  chances  are  against  him. 

RADIO  ENGINEERS 

RADIO  engineers  fall  into  three  classes: 
operating,  designing,  and  research.  Of 
course  these  categories  overlap,  and  a  compe- 
tent engineer  will  not  be  lost  in  changing  from 
one  function  to  another.  The  operating  en- 
gineer, as  the  term  indicates,  is  concerned  with 
actual  handling  of  equipment.  In  this  class, 
therefore,  would  fall  the  technical  staffs  of 
broadcasting  stations,  and  the  men  who  handle 
the  machinery  of  high-power  wireless  telegraph 
circuits.  The  designing  engineer,  somewhat 
farther  in  the  background,  takes  care  of  the 
layout  of  apparatus  and  its  adaptation  to 
specific  uses.  Farthest  removed  is  the  re- 
search worker,  whose  business  it  is  to  antici- 
pate the  needs  of  the  future  and  to  develop  new 
and  improved  methods  of  transmission  and 
reception. 

What  has  been  said  above  about  the  char- 
acter qualifications  of  the  operating  man  in 
general  applies  in  eve-ry  particular  to  the  oper- 
ating engineer.  He  must  be  quick  in  thought 
and  execution  and  not  easily  rattled  in  emer- 
gencies. He  must  know  how  to  cooperate  with 
people  who  are  not  interested  in  and  usually 
have  little  understanding  of  his  problems, 
without  letting  the  attendant  difficulties  get 
on  his  nerves.  If  he  is  a  telegraph  man,  his  con- 
tact will  be  with  traffic  officials  and  operators 
with  little  or  moderate  technical  training  and 
an  overwhelming  desire  to  get  things  running 
immediately,  if  not  sooner,  and  to  keep  them 
running  all  the  time,  if  not  longer.  The  tech- 
nical man  may  be  nursing  along  a  200-kilowatt 
alternator  out  at  some  high-power  station,  and 
when  the  local  lighting  company  drops  the 
supply  voltage  a  few  notches  he  may  have  to 
ask  the  traffic  people  for  time  out  to  retune. 
In  ten  minutes  the  voltage  comes  back  to 


Making  Radio  Your  Business 


193 


broadcasting 


normal,  and  the  job  has  to  be 
done  all  over  again.  It  takes 
only  a  few  minutes,  but  to  the 
traffic  man,  staggering  under 
a  load  of  urgent  messages, 
those  minutes  are  very  pre- 
cious. Or,  at  a  receiving  sta- 
tion, signals  may  be  weak  at 
times,  and  one  has  to  explain 
why  less  high  speed  is  being 
handled  than  last  July. 

Again,  at  a 
station,  the  operator  is  the 
connecting  link  between  the 
performer  and  the  audience; 
neither  must  be  kept  waiting, 
and  any  interest  they  mani- 
fest in  the  technical  features 
and  difficulties  is  of  necessity 
very  casual.  If  a  reactor  breaks  down  in  the 
plate  circuit  during  a  concert,  and  the  set  begins 
togoglug-glug-glug  in  the  middle  ofCaroNome, 
who  will  pity  the  poor  broadcast  operator  or 
speak  of  him  charitably  on  the  commuters' 
express  the  next  morning?  Such  an  accident 
simply  mustn't  happen.  And  it  rarely  does. 
It  is  surprising,  considering  the  newness  of 
radio  and  thecomplexity  of  transmitting  equip- 
ment, how  rare  and  brief  the  interruptions  are. 
But  if  this  is  so,  it  is  not  by  any  special  dis- 
pensation of  Providence,  but  by  foresight,  pro- 
vision against  weaknesses,  ample  safety  mar- 
gins, and  unceasing  observation  and  striving 
for  improvement  on  the  part  of  the  men  who 
design  and  run  the  sets. 

The  designing  engineer  converts  ideas  which 
have  been  found  to  work,  into  operable  appara- 
tus. The  research  engineer  tries  to  dig  up 
ideas  which  will  work.  They  must  work,  of 
course,  not  only  in  the  laboratory,  but  in  the 
field.  Hence  the  research  worker  requires  a 
physical  sense  which  will  restrain  and  guide 
him  in  his  search  for  new  methods.  Lacking 
this,  his  tendency  will  be  to  turn  out  plans  for 
intricate  and  unstable  apparatus  which  no 
amount  of  capable  designing  will  save  from  the 
scrap-heap.  At  the  same  time  he  is  usually 
a  more  imaginative  individual  than  his  col- 
leagues in  the  other  branches  of  the  art,  and  his 
work  is  more  closely  allied  to  that  of  the  artist 
or  the  pure  scientist.  He  is  frequently  better 
versed  in  fundamental  theory  that  the  other 
classes  of  engineers;  he  must  be,  in  fact,  in 
order  to  be  in  a  position  to  utilize  the  work  of 
the  pure  scientists  and  mathematicians.    It  is 


WHO  WILL  PITY  THE   POOR  BROADCAST  OPERATOR 
Or  speak  of  him  charitably  on  the  commuters'  express  the  next  morning  ? 


with  the  latter  that  novel  ideas  usually,  though 
by  no  means  always,  originate.  Thus  we  have 
an  Oliver  Heaviside  investigating  the  prop- 
erties of  electrical  lines  and  cables,  and  putting 
his  conclusions  into  forbidding  mathematical 
form,  and  a  few  decades  later  a  Pupin  digesting 
Heaviside's  formulations,  drawing  practical 
conclusions,  and  ultimately  producing  the 
methods  of  inductance  loading,  which,  with 
the  development  of  the  vacuum-tube  amplifier, 
have  made  transcontinental  telephony  pos- 
sible. The  research  engineer  is  thus  on  the 
second  rung  of  the  ladder  which  leads  from 
ideas,  more  or  less  in  the  abstract,  to  concrete 
machinery  operable  by  fallible  human  beings. 
A  man  well  endowed  with  scientific  curiosity, 
who  wishes  to  work  in  an  atmosphere  of  quiet 
and  orderly  pursuit  of  knowledge  without  re- 
gard to  the  vexatious  details  of  practical  ap- 
plication, is  best  off  in  academic  research. 
With  somewhat  the  same  bent,  but  a  little  less 
zeal  for  reducing  all  ideas  to  a  clearly  expressed 
physical  basis,  and  more  tendency  to  turn  out 
something  which  can  be  fitted  into  the  complex 
machinery  of  industry,  he  may  make  a  good 
industrial  research  man.  Given  still  less  pre- 
occupation with  ideas  as  such,  and  the  type 
of  mind  which  does  not  shrihk  from  minutia — 
whether  to  use  a  6-32  or  an  8-32  machine 
screw,  or  how  thick  to  make  a  panel,  or  how 
many  turns  of  wire  to  use  in  a  coil — always 
with  an  eye  to  the  greatest  durability  and  ef- 
ficiency at  the  least  expense,  we  have  the  ma- 
terial for  a  designing  engineer.  Of  course,  as 
in  other  fields,  a  capable  man  knows  a  lot  about 
one  thing  and  a  good  deal  about  everything 


194 


Radio  Broadcast 


else.  A  first  class  designing  engineer,  for  ex- 
ample, will  be  familiar  with  the  outstanding 
ideas,  at  least,  of  men  like  Clerk  Maxwell, 
Hertz,  and  Heaviside;  he  will  have  original 
ideas  for  improvements  in  the  art  and  be  at 
home  in  a  laboratory;  he  will  have  the  command 
of  detail  and  knowledge  of  materials  and  man- 
ufacturing methods  enabling  him  to  draw  up 
plans  for  efficient  apparatus,  and  in  a  pinch 
he  will  be  able  to  operate  an  actual  station. 

OTHER  OPPORTUNITIES 

MANY  other  branches  of  technology  might 
be  mentioned  in  this  outline  of  the  vary- 
ing functions  of  the  radio  engineer.  The  test 
shops,  for  example,  have  turned  out  some  of 
the  leading  technicians  in  the  field.  In  a  test 
shop  one  learns,  as  in  no  other  place,  the 
method  of  operating,  kinks,  and  limitations  of 


HE  MADE  RADIO  HIS  BUSINESS 

Edwin  H.  Armstrong 'has  been  responsible,  within  the 
past  ten  years,  for  three  of  the  most  important  radio  de- 
velopments. Before  the  War,  he  invented  regeneration, 
which  makes  long-distance  reception  possible  with  a  min- 
imum of  equipment.  During  the  War,  he  devised  a  system 
of  reception  called  the  super-heterodyne,  used  at  the  time 
for  intercepting  enemy  messages  on  very  short  wavelengths 
and  now  becoming  popular  for  long-distance  broadcast 
reception.  Last  year  he  disclosed  his  most  recent  inven- 
tion—  super-regeneration.  Among  the  apparently  un- 
limited possibilities  of  this  form  of  reception  is  long- 
distance work  with  a  single-tube  loop  set 


apparatus.  Not  only  that,  but  one  gains  an 
assurance  in  handling  apparatus  which  is 
hardly  obtainable  elsewhere.  In  a  test  shop 
an  engineer  gets  his  baptism  of  fire. 

In  one  test  shop  where  1  worked  it  was  the 
fashion  to  thumb  one's  nose  at  a  short  circuit 
arc  immediately,  if  one  retained  the  power  of 
movement  after  the  accident;  no  other  reflex 
was  considered  comme  il  fant.  Not  that  short 
circuits  are  welcome,  but  they  occur  in  elec- 
trical practice,  and  in  a  test  shop  one  learns  not 
to  be  disconcerted  when  the  fireworks  start. 
And  there  are  many  tricks,  such  as  the  pre- 
liminary jerking  in  and  out  of  the  switch  at  the 
first  test  of  a  piece  of  apparatus,  which  form 
part  of  the  equipment  of  a  good  electrician  and 
save  a  great  deal  of  money  in  the  long  run. 
There  is  no  other  place  like  a  test  room  for 
learning  these  tricks. 

RADIO  DEGREES? 

PEOPLE  new  to  the  field  are  sometimes  in- 
;  fluenced  by  the  aggregations  of  letters 
which  some  of  the  experts  and  writers  put 
after  their  names.  Most  of  these  mean  about 
as  much  as  the  title  of  "  Professor"  prefixed  to 
the  name  of  instructors  in  boxing  or  the  gentry 
who  teach  you  to  play  the  piccolo  in  four 
lessons.  As  yet  no  institution  of  good  acad- 
emic standing  has  established  any  such  degree 
as  "  R.  E.,"  for  example,  and,  although  a  man 
putting  these  letters  after  his  name  may  be  a 
capable  worker,  they  merely  represent  his  own 
idea  of  himself  and  should  be  taken  with  the 
same  reserve  as  advertisements  in  general.  A 
certain  discrimination  should  also  be  exercised 
in  the  matter  of  the  weight  given  to  member- 
ship in  engineering  societies.  These  organi- 
zations play  an  important  role  and  everyone 
of  consequence  belongs  to  them,  but  it  is  not 
generally  known  that  for  an  associate  member- 
ship the  only  qualifications  are  interest — not 
necessarily  competence — in  the  art,  conven- 
tionally good  business  morals,  and  the  ability 
to  spend  five  or  ten  dollars  a  year  for  dues. 
For  the  higher  grades — memberor  fellow, — -some 
four  and  seven  years  of  actual  engineering  ex- 
perience are  requisite,  and  to  that  extent  mem- 
bership in  these  grades  has  some  bearing  on 
the  standing  of  the  engineer  in  question. 
Holding  of  office  in  the  societies,  present  or 
past,  is  of  course  an  indication  that  the  in- 
dividual is  respected  by  his  colleagues  and  may 
be  taken  as  safe  evidence  of  high  professional 
standing.    Similarly,  technical  degrees  from 


Making  Radio  Your  Business 


195 


universities  of  good  standing,  or  study  under 
acknowledged  authorities,  may  reasonably  be 
taken  into  account. 

THE   RADIO  BUSINESS 

THE  business  side  of  radio  is  hardly  within 
the  scope  of  this  article;  success  is  here  a 
matter  of  general  business  acumen,  plus  special 
knowledge  of  the  field  and  its  particular  patent 
and  commercial  difficulties.  Broadcasting  has 
of  course  changed  the  entire  aspect  of  things  in 
radio.  It  is  only  necessary  to  consider  the 
case  of  one  manufacturer  whose  experience 
dated  back  to  the  very  earliest  days  of  radio 
in  the  United  States,  and  who  maintained  his 
business  tolerably  well  in  the  spark-set  years, 
and  then,  after  almost  two  decades  of  moderate 
prosperity,  failed  when  he  tried  to  swing  an 
ambitious  program  in  manufacturing  broad- 
cast equipment.  Apparently  with  the  greater 
opportunities  of  the  radio  telephone  boom  he 
did  not  sense  the  instability  of  the  new  market, 
the  necessity  of  meeting  severe  competition, 
and  the  adjustments  required  in  manufactur- 
ing for  a  new  class  of  users.  So  he  went  to  the 
wall  just  as  fast  as  any  newcomer.  In  radio, 
as  elsewhere,  people  who  try  to  become  million- 
aires in  haste  repent  at  leisure. 

THE  BROADCASTING  GAME 

BROADCASTING  has  opened  up  a  con- 
siderable number  of  new  positions.  The 
personnel  of  a  first-class  station  may  include 
a  program  manager,  who  interviews  prospec- 
tive artists  and  makes  arrangements  for  out- 
of-the-studio  broadcasting,  several  announcers, 
and  a  technical  staff,  consisting  of  control 
operators,  transmitter  attendants,  and  out- 
side or  pick-up  men.  The  control  operator 
monitors  the  outgoing  material  and  makes  in- 
dicated adjustments,  such  as  increasing  or  de- 
creasing the  amount  of  modulation,  setting  the 
accompaniment  at  the  proper  loudness  rela- 
tive to  the  singer,  and  so  on.  The  transmitter 
operator  watches  the  tube  set,  checking  the 
wavelength  and  antenna  current,  and  listen- 
ing in  at  short  intervals  for  distress  signals  at 
sea,  which  necessitate  immediate  shutting  down 
of  the  transmitter.  The  outside  men  take  care 
of  acoustic  exploration  at  theatres  and  halls 
from  which  special-event  broadcasting  is  con- 
templated, the  setting  of  the  microphones, 
necessary  tests,  and  supervision  during  the 
actual  transmission.  Of  course  in  most  sta- 
tions there  is  not  as  much  specialization  as  this, 


©  Underwood  &  Underwood 


HE  HAS  HAD  A  FINGER  IN  MANY  RADIO  PIES 

Elmer  E.  Bucher,  born  in  Akron,  Ohio,  in  1885,  and  edu- 
cated at  the  Academy  in  Oberlin,  Ohio,  joined  the  De 
Forest  Wireless  Telegraph  Company  as  experimental 
engineer  in  1903.  Later,  he  was  active  as  construction 
and  installation  engineer,  organizer  of  radio  schools,  in- 
ventor, and  radio  editor  and  author.  His  "  Practical 
Wireless  Telegraphy "  is  the  best-known  of  his  many 
books  on  radio.  He  is  at  present  managing  the  sale  of 
amateur  and  broadcast  equipment  for  the  Radio  Corpora- 
tion of  America 

and  one  man  may  handle  most  of  the  routine 
of  the  studio.  As  soon  as  one  gets  into  out- 
side work,  however,  a  good-sized  staff  becomes 
imperative. 

An  ear  for  music  and  sensitiveness  to  caco- 
phanous  elements  are  among  the  special  quali- 
fications of  the  broadcasting  station  operator. 
The  more  he  knows  about  the  engineering  end 
■ — the  special  features  of  tube  set  operation, 
the  technique  of  electrical  voice  reproduction, 
and  so  on — the  better,  but  in  addition  to  these 
fundamental  factors  he  must  be  something  of  a 
musician  and  expert  in  practical  acoustics.  If 
he  lacks  these  qualities,  he  will  often  be  in  the 
position  of  knowing  less  about  the  mechanics  of 
his  job  than  the  performers  in  the  studio,  many 
of  whom  have  had  experience  in  the  closely  re- 
lated field  of  phonograph  recording.  Social 
qualities  are  also  of  more  importance  in  the 
broadcasting  field  than  in  other  branches  of  the 
art,  since  the  personnel  of  a  station  is  in  contact 
with  outsiders  of  prominent  position  and  good 
breeding.  The  broadcasting  specialist,  accord- 
ingly, has  to  try  to  make  himself  a  combination 
concert  hall  manager  and  engineer.  This  ques- 
tion of  general  cultivation  and  social  case  is  like- 
wise prominent  in  the  selection  of  announcers. 


196 


Radio  Broadcast 


<- 

HE  CAME,  HE  SAW,  HE  BECAME  A 
:   RADIO  MAN 

At  the  age  of  sixteen,  David  Sarnoff  persuaded  the 
superintendant  of  the  Marconi  Company  that  he 
was  the  "Boy  wanted."  He  soon  became  an 
operator,  than  manager  of  the  Sea  Gate  station, 
then  sailed  to  the  Arctic  as  wireless  operator  on  a 
sealing  vessel.  Returning,  he  enrolled  as  student 
in  electrical  engineering  at  the  Pratt  Institute  night 
school,  in  Brooklyn.  His  next  position  was  that  of 
Inspector,  then  Chief  Inspector  for  the  Marconi 
Company.  In  September,  1922 — at  the  age  of  32 
— he  was  elected  Vice-President  and  General  Man- 
ager of  the  Radio  Corporation.  He  is  the  man  who, 
eleven  years  ago,  received  the  message  in  New 
York,  from  the  S.S.  Olympic,  1400  miles  at  sea,  giv- 
ing first  confirmation  of  the  sinking  of  the  Titanic 


FRANK  M.  SQUIRE,  OF  THE  DE  FOREST  CO. 
Starting  in  radio  as  an  amateur,  he  entered  the  game  professionally  in  the  draughting 
end.  He  worked  with  the  A.  H.  Grebe  Company  as  draughtsman,  and  finally  as  Chief 
Engineer.  Later,  he  organized  the  Radiocraft  Company,  of  which  he  is  now  Presi- 
dent, in  addition  to  being  Chief  Engineer  of  the  De  Forest  Company.  His  out- 
standing contribution  to  broadcast  reception  goes  by  the  name  of  the  De  Forest 

D7-A  Reflex  Receiver 


The  writer  has  had  occasion  recently  to  give 
counsel  on  the  matter  of  taking  up  radio  as  a 
profession  to  several  young  men  of  high  school 
age,  and  an  outline  of  his  recommendations 
may  be  of  interest  to  readers  in  somewhat  the 
same  position.  The  first  desirable  step  is  to 
get  into  practical  touch  with  the  field  through 
amateur  activities — reading  the  periodical  liter- 
ature, building  sets,  joining  radio  clubs  and 
becoming  junior  members  of  the  engineering 
societies.  It  is  best  to  go  to  a  college  or  tech- 
nical school,  specializing  in  electrical  engineer- 
irrg^not  that  a  B.  S.  or  an  E.  E.,  as  such,  makes 
an  engineer  of  a  man,  but  it  affords  him  a  good 
foundation,  enables  him  to  make  pleasant  and 
valuable  personal  connections,  and  gives  him,  in 
later  years,  the  satisfaction  of  feelingthat  he  has 
not  overlooked  any  good  bets  in  preparation. 
This  point  is  emphasized,  it  should  be  added, 
by  associates  of  the  writer  for  whom  he  has  the 
highest  respect,  and  who,  lacking  academic 
preparation,  feel  nevertheless  that  the  time 
and  capital  is  advantageously  invested.  Dur- 


ing vacations,  if  it  is  at  all  practicable,  the 
student  should  try  to  obtain  temporary  em- 
ployment in  commercial  operating,  as  an  ap- 
prentice or  junior,  or  factory  experience,  less 
for  the  income  obtainable  in  this  way  than  for 
the  value  of  coordinating  practice  and  theory. 
Attention  should  be  devoted  to  code  practice 
and  a  commercial  operator's  license  secured  as 
soon  as  possible.  Although  radio's  centre  of 
mass  may  be  shifting  from  telegraphy  to  teleph- 
ony, the  relations  between  the  two  will  of 
necessity  remain  intimate;  operators  of  broad- 
casting stations,  for  example,  are  required  to 
have  commercial  telegraphers'  licenses  at  the 
present  time.  On  the  other  hand,  it  is  clear 
from  what  has  been  said  above  that  courses  in 
the  arts,  such  as  a  study  of  the  history  of 
music;  and  such  experience  as  may  be  obtained 
in  playing  in  a  college  orchestra,  for  example, 
will  be  quite  valuable,  even  looking  at  the  ques- 
tion from  a  narrow  utilitarian  viewpoint,  with- 
out regard  to  humanizing  and  cultural  in- 
fluences. 


Using  the  "Inverse  Duplex"  with 
Various  Kinds  of  Tubes 

By  DAVID  H.  CRIMES 

This  article,  written  by  the  inventor  of  the  Inverse  Duplex  circuit,  discusses,  from  the  standpoint  of 
practical  operation,  the  hook-up  of  which  the  theory  was  explained  by  Mr.  Charles  H.  Durkee  in  the 
April  number. 

Since  that  first  article  appeared,  we  have  been  deluged  with  letters,  some  hundreds  of  them,  asking 
every  imaginable  question  about  the  theory,  construction,  and  operation  of  the  Inverse  Duplex.  The  present 
article  has  been  written  by  Mr.  Grimes  at  our  request,  to  answer  many  of  the  questions  that  have  been  asked 
by  correspondents,  and  to  let  others  know  something  of  the  possibilities  of  this  circuit. 

Briefly,  the  Inverse  Duplex  is  a  method  of  employing  tubes  for  radio  and  audio-frequency  work 
simultaneously,  without  overloading  them — the  heaviest  audio-frequency  currents  flowing  in  the  tube  where 
the  weakest  radio-frequency  current  is  flowing. — The  Editor. 


SINCE  the  publication,  in  Radio 
Broadcast,  of  some  of  the  details  of 
the  Inverse  Duplex  receiver1  there 
must  have  been,  conservatively  speak- 
ing, at  least  two  million  questions 
asked  concerning  various  parts  of  the  circuit. 
As  a  result  of  the  much  appreciated  cor- 

v'  1.300  Miles  on  a  One- Foot  Loop,"  by  Charles  H. 
Durkee,  April,  1923. 


respondence,  I  have  learned  several  things 
concerning  the  operation  of  the  hook-up  which 
would  otherwise  have  taken  me  several  years! 
And  it  is  the  purpose  of  this  article  to  give 
the  radio  fan  at  large  some  of  the  benefits  which 
I  have  received  individually  from  him. 

As  with  all  new  developments,  there  are 
many  things  which  have  to  be  known  by  the 
enthusiast  before  he  cm  successfully  dupli- 


THE  LAYOUT  FOR  THE  AUDIO-FREQUENCY  PART  OF  THE  INVERSE  DUPLEX 


198 


Radio  Broadcast 


Wm 


BOTTOM  VIEW  SHOWING  RADIO-FREQUENCY  ASSEMBLY  FOR  THE  3-TUBE  CIRCUIT 


cate  the  Inverse  Duplex,  even  though  he 
thoroughly  understands  the  principle.  Such 
supposedly  simple  details  as  equipment  as- 
sembly, method  of  wiring,  types  of  tubes,  volt- 
age of  batteries,  etc.,  immediately  take  on 
immense  importance. 

The  circuit  details  disclosed  in  the  April 
number  of  Radio  Broadcast  were  necessarily 
applicable  to  only  one  type  of  apparatus,  es- 
pecially the  tubes,  as  the  purpose  of  that  article 
was  to  outline  theory,  rather  than  practice. 
With  the  advantage  of  the  theory  fairly  well 
appreciated,  it  may  be  of  interest  to  you  to 
learn  what  has  been  found  best  in  practice,  by 
myself  and  others. 

Most  of  the  troubles  encountered  in  the 
operation  of  the  Inverse  Duplex  arise  from  the 
radio  frequency  part  of  the  circuit.  If  you 
have  had  little  or  no  experience  with  radio 
frequency  circuits,  the  following  suggestions 
will  prove  helpful  to  you.  All  leads  from  the 
radio  transformers  to  the  grids,  plates  and  by- 
passing condensers  should  be  as  short  as  it  is 
possible  to  make  them.  These  wires  are  carry- 
ing high  frequency  alternating  currents  and  if 
run  near  other  wires  or  apparatus  they  are 


likely  to  "cross  over"  into  them  through  the 
capacity  between  them,  just  as  they  do  be- 
tween the  plates  of  a  condenser.  This  will 
cause  no  end  of  trouble.  The  photograph 
showing  the  equipment  layout  indicates  the 
closeness  of  the  radio  transformers  and  tubes. 

Next,  radio  frequency  amplification,  unless 
properly  designed,  has  a  tendency  to  oscillate 
or  howl  and  to  the  novice  with  little  experience, 
it  is  almost  impossible  to  stop  it.  This  is 
mostly  a  problem  of  radio  transformer  con- 
struction, but  even  with  a  given  transformer 
which  tends  to  oscillate,  there  are  several  tricks 
which  may  be  employed  to  stabilize  it. 

Radio  transformers  have  to  be  pretty  care- 
fully built,  and  even  then  are  best  suited  to 
certain  types  of  vacuum  tubes.  Some  trans- 
formers which  are  absolutely  successful  on, 
say,  the  Radiotron  tubes,  are  very  poor  on  any 
other  type  of  tube.  It  is  impossible,  generally 
speaking,  to  use  indiscriminately  any  type  of 
vacuum  tube  with  any  type  of  radio  trans- 
former. Therefore,  in  purchasing  your  tubes 
and  R.  F.  transformers,  be  certain  that  they 
are  of  a  design  suitable  for  operation  with  each 
other. 


Using  the  "Inverse  Duplex"  with  Various  Kinds  of  Tubes 


199 


UV  ZOI-A  RADIO 


UVZOI-A  RADIO 


UV  200 


4001 


-00Z5 


.001 


SEC. 


AUDIO 


PRIM. 


.001 


25^11.  RHfO. 


•  001 


4^FIL  RHE0. 


4  DRY  CELLS  IN  SERIES  L-^ 
IN  GROUPS  OF  TWO  OR  THREES" 


SEC.  ;-  AUDIO 


PRIM. 


-mini 


lllllllllr-1— lllllil 


16-20  V. 


PLATE  BATTERY  TAPPED 
OFF  FROM  22V.  OR  UR 


FIG.  I.     HOW  TO  EMPLOY  A  UV-200  AND  TWO  20I-A  S 
25-ohm  rheostats  are  used  for  the  201-A's,  and  the  common  4  to  6-ohm  rheostat 
controls  the  UV-200.    Dry  cells  in  series-parallel  are  used  to  light  the  filaments 


T 


BEGIN  AT  THE  BEGINNING 

HE  best  possible  way  to  proceed  in  wiring 
up  an  Inverse  Duplex  circuit  is  to  connect 
up  merely  the  two  stages  of  radio  and  a  de- 
tector to  start  with.  If  no  results  are  ob- 
tained on  this,  it  is  useless  to  expect  anything 
by  adding  the  two  stages  of  audio.  The  audio 
stages  function  to  make  louder  the  results  al- 
ready obtained  by  the  detector  tube.  Hence 
it  is  absolutely  necessary  to  secure  results 
there  before  proceeding  further. 


One  of  the  features  of  the  Inverse  Duplex 
circuit  is  the  easy  and  ready  way  in  which 
trouble  may  be  located.  The  hook-up  can 
be  cut  into  three  separate  and  distinct  circuits 
— the  radio,  detector,  and  audio  connections. 
Any  one  of  these  three  may  not  be  operating 
properly  due  to  troubles  common  to  radio  cir- 
cuits, detector  circuits,  or  audio  circuits. 

For  instance,  on  loop  reception,  it  is  some- 
what difficult  to  make  a  so-called  "hard" 
tube,  such  as  the  UV-201,  act  properly  as  a 
detector  on  only  two  stages  of  radio.    On  the 


l  DRY  CEILS  IN  SERIES 
IN  2  GROUPS 


BATTERY  TAP  VARIABLE 
"FROM  ll\  VOLTS  UP 
ADJUSTED  FOR  BEST  RESULTS 


FIG.  2.     THE  SAME  CIRCUIT  ADAPTED  FOR  USE  WITH  A  WD- 1  I   OR  WD-I2 
Note  the  15-volt  tap-off  for  detector-tube  filament 


20O 


Radio  Broadcast 


TO  PHONE 


T0"B"  BAIT. 


FIG.  3. 

SHOWING  HOW  TO  ADD  A  STAGE 
OF  STRAIGHT  AUDIO  TO  THE  IN- 
VERSE DUPLEX 


4-1  AUDIO 


TO  A  BATT. 


TO  B  BATT. 


other  hand,  a  "soft"  tube  such  as  the  UV- 
200  will  do  this  easily.  There  are  detectors 
and  detectors,  varying  over  all  known  ranges 
of  sensitivity.  A  great  deal  will  depend,  natur- 
ally, on  the  sensitivity  of  your  detector  for 
best  results.  The  April  article  recommended 
a  UV-200  tube  as  a  detector.  This  tube  does 
not  require  a  grid  condenser  or  leak  and  the 
grid  wire  should  lead  back  to  the  negative  side 
of  the  filament.  A  UV-201  or  201 -A  tube  is 
not  recommended  here  for  a  detector. 

USING  DRY  CELL  TUBES 

THIS  brings  up  the  dry-cell  situation  as  ap- 
plying to  my  circuit.  The  same  thing 
holds  true  in  this  case.  When  satisfactory 
radio  amplification  is  obtained  and  successful 
detection  is  secured,  the  rest  is  easy.  The  new 
UV-201-A  tubes  which  will  operate  on  low 
enough  currents  to  permit  their  use  with  dry 
cells,  cause  considerable  difficulty  in  radio 
circuits  unless  special  precautions  are  taken. 
1  have  found  that  the  easiest  way  to  secure 
stability  with  these  tubes  on  radio  frequency 
is  to  drop  the  plate  voltage  to  45  volts  and 
sometimes  even  lower.  Dropping  the  filament 
voltage  below  5  volts  often  helps. 

For  a  detector  tube  on  dry  cell  operation, 
the  UV-200  can  hardly  be  recommended  be- 
cause of  the  high  filament  current  required. 
It  is  possible  to  use  it  but  several  banks  of  dry 
cells  must  be  connected  in  parallel  to  hold  up 
for  any  length  of  time.  The  expense  of  such 
operation  becomes  greater  than  the  mainte- 
nance of  storage  batteries  and  is  not  advisable. 
The  UV-201 -A  tubes  have,  in  my  experience, 
not  responded  as  detectors  to  weak  enough  sig- 
nals to  permit  their  use  with  only  two  stages 
of  radio  on  a  loop.  The  WD-i  1  is  apparently 
much  better  but  requires  a  different  line-up 
in  the  filament  battery  circuits.  It  operates 
on  only  about  1  volt  while  the  UV-201-A  tubes 
function  on  from  4  to  5  volts. 

Many  questions  have  arisen  regarding  the 
omission  of  the  filament  rheostats  on  the 


amplifying  tubes  in  earlier  drawings.  These 
were  purposely  left  out  because  the  UV-201 
tubes  would  take  the  battery  voltage  (about 
5!  volts  after  the  filament  current  had  gone 
through  the  battery  leads)  directly,  with  only 
a  small  decrease  in  their  life.  It  was  thought 
that  omitting  these  rheostats  would  simplify 
the  adjustment  of  the  set  to  a  sufficient  degree 
to  compensate  for  the  somewhat  shorter  life  of 
the  tubes.  The  confusion,  however,  has  been 
so  great  that  1  am  now  suggesting  that  the 
amplifying  tubes  have  rheostats  inserted  as 
shown  in  the  accompanying  diagrams  (Figs. 
1 ,  2,  and  5). 

Having  assumed,  now,  that  the  radio  fre- 
quency part  of  your  circuit  has  been  adjusted 
to  function  satisfactorily,  we  are  ready  to  con- 
sider the  specific  difficulties  encountered  in 
duplexing  the  audio  on  the  radio  tubes.  Most 
fans  have  little  or  no  trouble  with  audio  cir- 
cuits, or  if  they  have,  they  have  learned  how 
to  overcome  them,  by  reversing  the  primary 
windings,  etc.  The  reversing  of  leads  on  the 
primaries  of  the  radio  transformers,  by  the 
way,  is  a  good  thing  to  try  when  troubled  with 
instability  in  the  radio  frequency  circuit. 

You  will  no  doubt  recall  what  was  said  in 
the  April  issue  about  overloading  the  tubes 
in  certain  types  of  "reflex"  circuits.  It  was 
also  brought  out  that  the  Inverse  Duplex 
greatly  helped  in  overcoming  this  trouble  by 
balancing  the  load.  Even  then,  if  the  in- 
coming energy  is  excessive,  as  is  the  case  on 
aerial  reception  for  local  work,  the  carrying 
limit  of  the  tubes  is  reached  and  poor  quality 
results.  In  this  case,  the  400-ohm  resistance 
would  not  be  sufficient  to  cut  the  energy  down 
to  a  reasonable  amount.  WD-i  1  tubes  are 
not  very  satisfactory  as  amplifiers  in  this  cir- 
cuit as  they  are  limited  in  energy  and  are  easily 
overloaded.  This  circuit  is  essentially  a  super- 
sensitive layout  and  will  not  stand  tremendous 
currents.  If  louder  reception  is  desired  on 
local  or  long  distance  stations  than  that  given 
by  two  stages  of  audio,  it  is  suggested  that  an 


Using  the  "Inverse  Duplex"  with  Various  Kinds  of  Tubes  201 


additional  tube  of  straight  audio  be  added 
between  the  set  and  the  reproducer.  The  sole 
purpose  of  this  tube  will  be  audio  amplification 
and  can  be  used  to  the  limit  of  its  ability  for 
that  purpose.  If  greater  range  is  desired,  a 
straight  radio  stage  may  be  connected  between 
the  loop  and  the  first  duplex  tube,  but,  of  course, 
this  has  a  tendency  to  overload  the  duplex 
tubes  on  local  reception.  Running  three  du- 
plex tubes  beside  the  detector  is  not  to  be  re- 
commended to  the  uninitiated,  although  it  has 
worked  out  perfectly  in  hundreds  of  cases  dur- 
ing the  past  year.  Until  the  amateur  has  fully 
familiarized  himself  with  the  duplex  peculiari- 
ties on  two  amplifier  tubes,  he  should  not 
tackle  the  three-amplifier  layout. 

ANY  LOOP  WILL  DO 

A ONE-FOOT  loop  was  referred  to  in  the 
previous  article  and  this  has  led  to  much 
confusion.  Many  readers  inferred  that  the 
circuit  would  operate  with  nothing  else.  Any 
kind  of  a  loop  will  work  on  the  circuit  provided 
the  number  of  turns  are  such  as  to  tune  prop- 
erly with  the  variable  condenser  for  the  wave 
lengths  desired.  The  smaller  the  loop,  the 
less  energy  it  will  pick  up  and  the  less  will  be 
the  range  for  a  given  sensitivity  of  circuit. 
Many  other  types  of  sets  have  operated  over 
considerable  distances  on  loops  ranging  all  the 
way  up  to  5  feet  on  a  side  or  even  larger.  The 
one-foot  loop  was  emphasized  merely  to  il- 
lustrate the  extreme  sensitivity  of  the  circuit. 
On  powerful  stations  up  to  175  miles  away,  1 


have  obtained  good  reception  on  a  4-inch  coil 
— the  secondary  of  a  variocoupler.  For  best 
all-round  results,  a  16-  to  20-inch  loop  with  8  to 
12  turns  of  wire,  spaced  J  inch  apart  is  sug- 
gested. On  a  three-foot  loop,  a  listener  in  New 
York  using  the  Inverse  Duplex  circuit  with 
two  tubes  and  a  crystal  detector,  has  picked 
up  stations  as  far  west  as  Kansas,  at  noon. 
This  size  loop  has  a  tendency  to  overload  the 
circuit  on  night  reception.  Overloading  is 
easily  ascertained  by  poor  quality  or  the  first 
or  second  amplifying  tube  acting  as  a  detector 
instead  of  the  regular  detector  tube. 

TWO  WAYS  OF  OVERCOMING  "  SILENCE " 

AFTER  all  the  above  suggestions  have  been 
.  followed,  there  will  be  cases,  no  doubt, 
where  the  fan  will  still  have  trouble.  There 
are  so  many  variables  which  can  cause  trouble. 
I  would  recommend  trying  two  additional 
changes  which  ordinarily  are  not  desirable. 
The  first  is  to  run  the  grids  of  both  amplifying 
tubes  back  to  potentiometers  instead  of  to  the 
negative  filament,  and  the  second  is  to  cut 
down  or  perhaps  eliminate  entirely  the  by- 
passing condensers  on  the  middle  tube.  This 
first  gives  broad  tuning  and  also  reduces  the 
audio,  while  the  second  materially  reduces  the 
range. 

The  audio  transformers  should  be  of  the 
3I  or  4  to  1  ratio  preferably.  Under  certain 
conditions,  especially  when  using  a  crystal  for 
a  detector,  the  first  audio  transformer  after  the 
detector  can  be  of  the  high,  or  10  to  1 ,  ratio. 


ADDED  RADIO  TRANSFORMER 
1  STAGE  CLEAR  RADIO  \ 


1ST  TUBE 
DUPLEX 


FIG.  4. 

HOW  TO  ADD  ONE  STAGE  OF 
STRAIGHT  "RADIO"  TO  THE  IN- 
VERSE DUPLEX 
Where  UV-201-A  tubes  are  used,  25- 
ohm  rheostats  should  be  connected  in 
series  with  the  filaments.  The  same 
thing  applies  to  the  arrangement 
shown  in  Fig.  3 


POTENTIOMETER 


SEC 


TO  B  BATT. 


f  AUDIO  p 

:  prim. 

TO  "A"  BATT. 


SEE  OTHER  DIAGRAMS  FOR 
REGULAR  DUPLEX  CONNECTIONS 


202° 


Radio  Broadcast 


UV  201-A 


RADIO 


UV  201-A 


UV  200 


POTENTIOMETERS 


Hllli 


HIIII 


6  VOLTS 


I6-2ZV. 


B  BATTERY  TAP- 
OFF  22  VOLTS  -  UP 


FIG.  5.     THE  STABILITY  OF  THE  CIRCUIT  IS  IMPROVED  BY  TWO  200-OHM  POTENTIOMETERS 

Note  that  in  this  case  there  is  no  by-pass  condenser  on  the  second  tube 


It  is  assumed  that  the  ordinary  troubles 
possible  in  radio  hook-ups,  such  as  open  trans- 
formers, poor  tubes,  broken  down  condensers 
and  run  down  B  batteries,  have  been  located 
and  eliminated.  It  is  naturally  beyond  the 
scope  of  this  article  to  cover  all  these  points, 
but  nevertheless  they  must  first  be  checked 
before  any  success  can  be  obtained.  Fully 
nine  out  of  ten  troubles  which  I  have  been  per- 
sonally called  to  remedy  were  due  to  such 
things  as  mentioned  above. 


If  I  have  in  any  small  degree  helped  the  radio 
fan  along,  I  shall  feel  amply  repaid,  and  to 
those  who  have  not  achieved  all  the  results 
they  had  a  right  to  expect,  I  can  only  suggest 
that  they  accept  the  advice  on  the  back  of  one 
of  the  earlier  automobile  handbooks:  after  all 
the  cures  for  possible  automobile  troubles  have 
been  given  throughout  a  vast  number  of  pages, 
the  final  statement  is  made,  "  Don't  forget 
that  this  machine  once  worked,  and  with 
proper  care  will  work  again." 


Radio  is  Expensive  for  the 
Married  Man 


By  ROBERT  OLIVER 


RADIO,  relatively  speaking,  is  not 
very  expensive  when  indulged  in 
by  a  single  man,  but  when  a 
married  man  succumbs,  it  is  dif- 
'  ferent.  Not,  as  you  may  have 
hastily  concluded,  because  the  places  where 
radio  apparatus  is  exposed  for  sale  make  a 
practice  of  jumping  a  married  man  harder  than 
they  do  the  bachelor,  but  because  of  one  item 
in  the  total  cost  which  is  submerged. 

If  you  are  a  married  man,  and,  like  many 
another,  goaded  to  a  point  where  you  feel  like 
an  outsider  amid  the  jargon  of  radio  fans,  you 


may  decide  to  investigate  and  perhaps  invest. 
But  listen.  There  is  one  item  that  belongs  on  the 
list  of  what  to  buy  that  you  never  can  dodge. 

This  item  belongs  in  the  class  of  things  that 
you  can  not  say  with  words.  Florists  advise 
saying  it  with  flowers. 

If  one  could  get  by  with  flowers  it  wouldn't 
be  bad.  But  flowers  don't  seem  to  suffice. 
One  man  I  know  had  to  get  his  wife  a  new  car 
and  teach  her  to  drive  it.  Thus,  when  he  came 
home  at  night  with  his  arms  full  of  parts  he 
could  pretty  safely  bank  on  his  wife's  being 
out  with  the  car. 


Radio  is  Expensive  for  the  Married  Man 


203 


Take  my  friend  Jennings.  Before  the  radio 
mania  seized  him,  he  was  as  keen  a  conservator 
of  the  old  savings  account  as  one  could  wish 
to  meet.  Now  Jennings  has  a  one-man  radio 
factory  going  full  blast  in  his  basement,  but 
the  price  he  pays  for  it  is  terrible.  His  wife 
has  an  ermine  cape  and  has  already  priced  cer- 
tain articles  of  jewelry  involving  platinum. 

Possibly  the  prospective  married  radio  en- 
thusiast who  has  an  idea  that  a  couple  of  hours 
will  be  sufficient  to  put  together  a  set  may 
pause  when  he  learns  that  radio  takes  time. 
It  takes  time  to  shop  around  for  apparatus. 
It  takes  time  to  read  radio  magazines.  One 
must  read  the  radio  advertisements.  One  must 
study  all  the  new  hook-ups  and  figure  out  the 
weekly,  one  might  say  daily,  batch  of  super 
circuits. 

As  for  any  one  particular  hook-up,  its  days 
are  as  grass :  as  a  flower  of  the  field,  so  it  flour- 
isheth;  for  the  wind-of -something-new  passeth 
over  it,  and  it  is  gone;  and  the  place  thereof 
shall  know  it  no  more. 

Take  the  radio  fan's  Sunday.  Almost  any 
Sunday  will  do.  His  routine  is  something  like 
this. 

7:00  a.  m.  The  fan  wakes  up  and  wonders 
if  a  C  battery  wouldn't  help  his  second  step. 
He  resolves  to  try  it  and  gets  so  interested  in  the 
idea  that  he  can't  go  back  to  sleep. 

7:15.  Gets  up  and  turns  off  the  current  on 
his  battery  rectifier. 

7:25.  Fixes  furnace  and  makes  a  side  trip  to 
work-bench.  Inspects  new  set  he  is  working 
on.    Finds  a   couple  of  loose  connections. 

7:30.  Lights  laundry  stove  to  heat  soldering 
iron.  While  soldering  iron  is  heating,  decides 
to  substitute  bus  bar  for  bell  wire  in  connections 
from  filament. 

8:00.  Remembers  that  rheostat  for  first 
step  makes  poor  contact,  decides  it  is  good 
time  to  take  it  out  and  put  in  new  one  bought 
yesterday. 

9:00.  Wife  calls  breakfast.  Soldering  iron 
poised  in  midair.  "  Can't  stop  just  now  dearie, 
be  there  in  a  minute."  Finishes  soldering,  puts 
tools  away  and  discovers  two  loose  taps  on 
inductance.  Better  fix  it  while  iron  is  hot. 
Iron  is  cold,  so  lights  gas  and  waits  for  iron  to 
heat. 

9:30.  Taps  all  fixed,  tears  himself  away, 
shaves  and  dresses.  Comes  down  to  breakfast. 
Wife  and  breakfast  cool. 

10:00.  Goes  down  to  fix  furnace  again. 
Makes    another   side   trip   to  work-bench. 


Starts  tracing  out  grid  and  plate  circuits. 
Finds  grid  leak  connections  very  loose.  Better 
solder  them.  Lights  gas  and  waits  for  solder- 
ing iron  to  heat. 

1 1  :oo.  While  iron  is  heating  decides  to  put 
some  spaghetti  on  plus  A  lead  to  prevent 
getting  it  crossed  with  90-volt  B  which  is  bad 
for  tubes. 

1 1 130.  Too  late  to  go  to  church.  Wife  gone 
to  church.  "Oh  well,  'sail  right.  Get  a  little 
time  to  myself  now."  Starts  laying  out  some 
radio  frequency. 

12:30.  Still  laying  out  radio  frequency. 
Decides  to  get  another  radio  freak  transformer 
to-morrow.    Saw  one  advertised  in  magazine. 

1:00.  Mess  call.  "Just  a  moment  dear, 
can't  come  just  now.    Be  there  in  a  minute." 

1 .30.  Responds  to  mess  call.  Wife  and 
mess  decidedly  cold. 

2:00.    Mess  over.    Not  a  very  chatty  meal. 

2:15.  Decides  it  might  be  a  good  plan  to 
"say  it  with  an  automobile  ride."  Skies 
brighten  a  bit  at  suggestion.    Goes  down  to 


"can't  stop  just  now,  dearie,  be  there  in 

A  MINUTE" 


204 


Radio  Broadcast 


I  VE     BEEN  THINKING, 
MY  DEAR 

That  you  need  a  rest.  How 
would  a  trip  to  California  strike 
you?" 


fix  furnace.  Makes  side  trip  to  bench  to  see 
if  everything  is  all  right.  Everything  not  all 
right.  Left  gas  burning  and  soldering  iron  is 
red  hot. 

2:20.  Decides  to  solder  a  couple  of  con- 
nections while  iron  is  hot. 

2:45.  Still  soldering.  Can't  make 'em  stick. 
Too  big  a  hurry.    Gets  sore  and  hot. 

3:00.  Still  soldering.  Hears  noise  upstairs. 
"All  right  dear,  be  there  in  a  moment." 

4:00.  Goes  up.  Finds  wife  gone  out. 
Noise  was  door  slamming.  "Oh,  all  right. 
It'll  gimme  a  little  time  to  myself.  Gosh, 
women  are  unreasonable." 

4:10.  Goes  down  to  work-bench,  now  that 
he  has  a  little  time  to  himself,  and  works  on 
radio-frequency  hook-up.  Decides  to  drill  new 
panel  bought  yesterday. 

5:00.  Panel  all  drilled.  Might  as  well 
mount  condenser  and  rheostats  now  that  he 
has  a  little  time  to  himself. 

6:30.  "Gosh  how  time  flies."  Wonder  if 
the  wife  has  returned.  Wife  still  out.  "'Sail 
right,  now  I've  got  a  little  time  to  myself." 

8:00.    Wife  returns.  Brrr! 

8:15.  Hooks  up  set  and  listens  in.  Gets 
sermon  entitled  "One  Day  of  Rest  in  Seven." 

8:16.    Decides    to    try    to    get  distant 


stations.  Local  stations  too 
strong. 

8:30.  Quits  and  goes  down 
to  fix  furnace.  Wishes  radio- 
frequency  hook-up  was  fin- 
ished. Better  go  and  look 
over  radio-frequency  hook- 
up. Makes  side  trip  to  work- 
bench. 

10:00.  Still  working  on 
radio  frequency.  Glances 
hurriedly  at  watch.  Wow — • 
10  o'clock  already! 

1 1  :oo.  Prepares  "tempor- 
ary" hook-up  of  radio  fre- 
quency. Tries  it.  Doesn't 
work.  Takes  it  back  to  base- 
ment. Decides  to  put  in 
condensers  on  transformers. 

12:00.  All  set  again  and 
ready  to  try.  Local  stations 
silent.  Doesn't  work.  Goes 
over  hook-up  plans  again. 
Remembers  article  in  maga- 
zine on  radio  frequency. 

12:30.  Funny  where  that 
magazine  went.  Goes  back 
and  tries  radio-frequency  hook-up  again.  It 
works  but  not  very  well. 

1  :oo.  Decides  to  quit  and  call  it  a  day. 
Gentle  reader,  perhaps  you  begin  to  gather 
the  importance  of  doing  something  to  thaw  out 
the  frigidity  resulting  from  such  a  schedule. 
The  only  way  is  to  search  out  some  of  the  wife's 
repressed  desires.  See  if  she  hasn't  a  complex 
centering  around  a  trip  to  California.  Every 
woman  has  such  a  complex,  something  that 
comes  to  the  surface  every  now  and  then,  under 
stress. 

Decide  upon  the  particular  complex  that 
makes  its  presence  known  most  frequently. 
Then,  with  casualness,  not  to  betray  the  hidden 
motive,  say  something  like  this:  "I've  been 
thinking,  my  dear,  that  you  really  need  a  rest. 
1  can't  get  away  myself,  but  how  would  a  trip 
to  California  strike  you?" 

Try  to  find  the  California  trip  complex  if 
possible.  It  is  really  much  better  than  a  fur 
or  diamond  complex.  I'll  tell  you  why.  Al- 
though furs  and  diamonds  are  more  enduring 
and  in  times  of  great  stress  may  be  hypothe- 
cated, perhaps,  still  there  are  advantages  about 
a  California  trip  for  the  wife  which  should  not 
be  overlooked — by  the  fan  who  wants  a  little 
time  to  himself. 


Art-. 


Putting  Your  Patent  Across 

How  to  Choose  Your  Lawyer.  A  Word  About  Foreign 
Patents.   Some  Popular  Illusions  Mercifully  Destroyed 

By  ROGER  SHERMAN  HOAR,  A.  B.,  M.  A.,  LL.  B. 

Former  Assistant  Attorney  General  of  Massachusetts 


TO  MOST  inventors,  the  patent  law 
seems  a  maze  of  complications.  It 
seems  complicated  merely  because 
everything  unknown  is  mysterious. 
But  as  soon  as  its  principles  are 
separated  from  technical  terms  and  from  the 
usual  hocus-pocus  with  which  some  lawyers  are 
fond  of  mystifying  their  clients,  it  becomes  a 
lucid  subject,  easily  understood. 

On  the  other  hand,  everything  about  which 
you  have  a  smattering  of  knowledge  seems 
easier  than  it  really  is. 

Now,  it  is  possible  for  any  intelligent  in- 
ventor to  handle  his  own  case  from  start  to 
finish,  by  following  the  book  of  rules  issued  by 
the  Patent  Office.  In  some  instances  it  may 
be  desirable  for  you  to  handle  your  own  case, 
as  for  instance  when  you  are  filing  your  ap- 
plication merely  for  the  purpose  of  saving  the 
expense  of  a  "search,"  or  for  the  purpose  of 
ascertaining  what  some  competitor  may  have 
up  his  sleeve. 

But,  in  general,  "  a  man  who  is  his  own  lawyer 
has  a  fool  for  a  client."  Did  you  ever  notice, 
in  reading  the  newspapers,  that  whenever  a 
lawyer  gets  into  trouble,  he  does  not  try  to 
handle  his  own  case,  but  rather  hires  the  most 
able  and  expensive  brother  lawyer  whom  he  can 
find.  If  lawyers,  who  know  all  the  short- 
comings of  their  own  profession  from  the  in- 
side, and  who  are  much  more  able  to  handle 
their  own  cases  than  any  layman  could  possibly 
be,  nevertheless  consider  it  advisable  to 
employ  an  attorney,  how  much  more  advisable 
is  it  for  a  layman  to  do  likewise!  To  show 
that  I  practice  what  I  preach,  I  will  state  that 
at  present  I  have  three  applications  of  my  own 
pending  at  Washington,  and  that  each  of 
them  is  in  the  hands  of  an  attorney  other  than 
myself. 

Since  April,  when  this  series  of  articles  started 
in  Radio  Broadcast,  I  have  been  deluged  by 
letters  from  readers,  and  a  large  proportion 
of  these  have  been  from  inventors  inquiring  as 
to  how  to  choose  a  patent  attorney. 


A  great  many  inventors  are  perplexed  by  the 
apparent  impasse  created  by  the  fact  that  the 
only  way  to  find  a  lawyer  is  by  his  advertise- 
ment, and  that  reputable  lawyers  do  not  adver- 
tise. Although  it  is  true  that  the  ethics  of  the 
profession  do  not  permit  lawyers  in  general  to 
advertise,  yet,  in  the  first  place,  it  is  not  in- 
ethical  to  use  an  advertisement  merely  stating 
one's  name,  one's  address,  one's  phone  number, 
and  the  fact  that  one  is  a  lawyer,  specializing 
in  certain  sorts  of  cases;  and,"  in  the  second 
place,  the  rule  against  advertising  has  been 
considerably  relaxed  in  the  case  of  patent 
lawyers,  for  they  are  not  in  as  good  a  position 
to  get  business  by  other  means  as  are  general 
practitioners. 

So  don't  worry  about  whether  your  lawyer 
advertises  or  not,  for  plenty  of  reputable  patent 
lawyers  do  advertise.  But  be  sure  and  give 
heed  to  what  he  claims  in  his  advertisements. 
And  especially  avoid  lawyers  who  guarantee 
results,  for  the  mere  fact  that  he  can  get  you  a 
patent  on  your  invention  means  practically 
nothing.  You  may  have  a  perfectly  wonderful 
invention,  and  yet  secure  an  absolutely  value- 
less patent  based  on  it,  especially  if  you  employ 
a  guaranteeing  attorney. 

There's  nothing  wonderful  in  being  able  to 
guarantee  results!  It  is  the  simplest  thing  in 
the  world  to  secure  a  patent !  I,  here  and  now, 
will  guarantee  to  get  any  one  a  valid  patent  on 
anything  under  the  sun,  new  or  old,  provided 
only  that  it  has  some  detail,  however  slight,  to 
distinguish  it  from  the  prior  art;  but  this  is 
not  particularly  clever  of  me,  for  any  other 
attorney  could  do  the  same.  We  would  not, 
however,  promise  that  the  patent  would  be 
worth  the  paper  it  was  printed  on. 

Closely  akin  to  the  patent  attorneys  who 
guarantee  results  are  those  who  impliedly 
guarantee  results  by  making  their  fee  contin- 
gent upon  success.  What  do  they  mean, 
"success"?  Contingent  fees  are  proper,  and 
even  desirable,  in  certain  fields  of  the  law,  not- 
ably personal  injury  suits  and  will-contests,  for 


206 


Radio  Broadcast 


in  such  cases  the  client  can  ill  afford  to  pay  a 
cent  if  he  loses,  but  can  well  afford  to  pay  a 
quarter,  or  a  third,  or  even  a  half,  of  his  total 
recovery,  if  he  wins.  Even  in  such  cases,  there 
is  a  temptation  for  the  lawyer  to  make  a  quick 
settlement  for  the  certainty  of  a  small  fee, 
rather  than  to  do  the  extra  work  necessary  to 
secure  a  larger  recovery.  But,  be  that  as  it 
may,  there  is  no  excuse  for  a  contingent  fee  in 
any  situation  where  it  is  impossible  to  measure 
accurately  the  value  of  the  results. 

The  third  class  of  lawyers  to  avoid  are  those 
who  charge  a  uniform  fee,  regardless  of  the 
amount  of  work  involved.  It  stands  to  reason 
that  they  will  give  just  as  much 
attention,  and  no  more,  to  the  case, 
than  is  necessary  to  secure  some  sort 
of  a  patent. 

It  is  hard  to  say  which  is  the  worst: 
guaranteed  results,  contingent  fees,  or 
uniform  charges,  for  they  all  are  akin. 

If  you  are  interested  merely  in 
getting  a  patent  on  your  invention,  then  by  all 
means  go  to  such  an  attorney.  But  if  you  want 
a  patent  carefully  drawn,  so  as  to  secure  you  the 
maximum  protection  against  infringement, 
consistent  with  the  state  of  the  prior  art, 
within  the  allowable  range  of  equivalents  of  the 
elements  of  your  invention,  then  you  should 
avoid  a  shyster  lawyer  as  you  would  avoid  a 
quack  doctor.  Go  to  the  best  firm  you  can 
afford,  and  be  prepared  to  pay  them  well,  on  a 
time  basis,  regardless  of  results. 

1 1  is  not  necessary  that  your  lawyer  be  an  ex- 
pert in  your  particular  field,  for  lawyers  are 
notably  adaptable.  At  the  Coast  Artillery 
School  during  the  War,  some  statistics  were 
compiled  to  show  the  relation  between  pre- 
vious education  and  standing  in  War  studies, 
the  object  being  to  induce  highly  trained 
technical  men  to  choose  the  Artillery  branch. 
The  figures  came  out  just  as  expected,  with  one 
startling  exception;  or  rather,  addition.  The 
lowest  grades  were  those  of  grammar-schooling 
or  less.  Then  came  the  high  school  graduates. 
Then  the  college  graduates.  Then  the  holders 
of  advanced  degrees:  M.A.  and  Ph.D.  in 
mathematics,  Civil  Engineer,  Mechanical  En- 
gineer, Electrical  Engineer,  etc.  But,  far  in 
advance  of  all,  in  a  group  sufficiently  large  to 
show  that  it  did  not  exist  by  mere  chance,  stood 
the  holders  of  the  LL.B.  So,  in  order  not  to 
spoil  the  statistics,  the  Army  authorities  lumped 
the  lawyers  in  with  the  engineers,  under  the 
head  of  "and  other  advanced  degrees." 


This  episode  shows  us  that  the  law-trained 
man  is,  by  nature,  so  adaptable  that  it  is  easier 
for  the  average  lawyer,  with  no  technical 
experience  at  all,  to  master  a  branch  of  engi- 
neering, than  it  is  for  an  engineer  to  switch  from 
one  branch  of  engineering  to  another.  So 
don't  worry  about  your  lawyer's  ignorance  of 
your  particular  line. 

It  is  much  more  important  for  a  lawyer  to 
understand  judicial  psychology  (i.  e.,  the  mental 
processes  of  his  courts),  than  it  is  for  him  to  be 
versed  in  the  law;  so,  all  other  things  being 
equal,  choose  a  former  Patent  Office  examiner 
to  handle  your  applications.  But,  if  possible, 
choose  one  who  has  been  graduated 
from  a  law  school  of  standing,  as 
otherwise  you  are  not  getting  a  really 
law-trained  man. 

For  searches,  choose  an  expert  in 
this  line  of  work.     Several  former 
Commissioners  and  Chief  Examiners 
have  made  conspicuous  reputations 
in  this  field. 

For  foreign  patents,  there  are  firms  who  do 
nothing  else,  having  their  representatives  in 
every  country  in  the  world.  Most  local 
patent  attorneys  are  totally  unfitted  for  this 
work;  but  you  should  have  your  American 
lawyer  cooperate  with  your  firm  of  international 
lawyers. 

For  drawing  assignments  and  similar  papers, 
a  general  practitioner  is  preferable  to  a  patent 
lawyer,  as  such  papers  are  governed  by  the 
general,  rather  than  by  the  patent,  law. 

For  court-work,  choose  a  good  trial  lawyer, 
who  understands  the  psychology  of  the 
particular  judge  before  whom  the  case  is  to 
be  tried,  but  have  your  patent  attorney  sit  in 
with  him.  Some  of  the  best  patent-trial  lawyers 
in  the  country  have  never  handled  a  single 
patent  application, and  someof  the  most  skillful 
claim-drafters  have  never  appeared  in  court. 

When  a  person  wishes  to  buy  or  sell  a  patent, 
the  thought  naturally  occurs  to  him  to  secure 
an  abstract  of  title  from  the  Patent  Office,  just 
as  one-  does  from  the-  Registry  of  Deeds  when 
dealing  with  real  estate.  But  there  is  a  great 
difference.  In  the  case  of  real  estate,  a  bona 
fide  purchaser  cannot  be  affected  by  a  deed 
which  has  not  been  recorded;  but  in  the  case 
of  patents,  unrecorded  papers  frequently  spoil 
the  entire  title. 

Interests  in  patents  can  be  vested  in  assign- 
ees, in  guarantees  of  exclusive  territorial  rights, 
in  mortgagees,  and  in  licensees. 


Putting  Your  Patent  Across 


207 


An  assignment  conveys  the  whole  interest  of 
the  patentee,  or  an  undivided  part  thereof, 
extending  throughout  the  whole  United  States. 

A  grant  conveys  exclusive  rights  under  the 
patent  throughout  some  specified  part  of  the 
country. 

The  meaning  of  "  mortgage  "  is  well  known. 

A  licensee  is  one  who  takes  an  interest  less 
than  or  different  from 
any  of  the  aforemen- 
tioned. A  license  may 
be  oral,  written  or 
printed,  and  if  written 
or  printed  must  be 
duly  signed.  In  the 
absence  of  words  to 
the  contrary,  a  license 
is  personal  to  the 
licensee,  and  cannot 
be  transferred. 

Assignments,  grants, 
mortgages,  and  pos- 
sibly exclusive  li- 
censes, must  be  writ- 
ten or  printed,  must 
identify  the  patent  by 
date  and  number  (or, 
if  the  invention  be 
unpatented,  must  give 
the  name  of  the  in- 
ventor, the  filing  date 
and  the  serial  number, 
if  any),  must  be  duly 
signed  and  acknowl- 
edged before  a  notary 
or  similar  official,  and 
must  be  recorded  in  the 

Patent  Office  within  three  months  of  execution, 
or  at  least  prior  to  the  execution  of  any  sub- 
sequent purchase  or  mortgage,  in  order  to  be 
valid  as  against  such  subsequent  purchase  or 
mortgage.  It  is  said  that  the  subsequent  pur- 
chaser or  mortgagee  has  "constructive  notice" 
of  the  recorded  conveyance.  Actual  notice  by 
the  purchaser  or  mortgagee,  prior  to  his  acquir- 
ing title,  is  equally  effective  to  invalidate  the 
subsequent  purchase  or  mortgage. 

And  now,  I  suppose,  you  would  like  to  know 
something  about  foreign  patents.  Obviously 
the  subject  can  merely  be  sketched  in  the 
brief  space  that  remains  to  me;  so  let  us  call 
this  merely  an  introduction  to  foreign  patents. 

If  you  decide  to  patent  abroad,  you  will 
wish  "to  get  in  under  the  Convention";  i.  e.,  to 
file  abroad  within  one  year  of  the  filing  date 


According  to  Mr.  Hoar,  most  people  are 
possessed  of  a  number  of  erroneous  ideas  re- 
garding patent  law  and  procedure.  In  this 
article,  he  sets  you  right,  with  a  jolt,  perhaps, 
but  with  no  less  shrewdness  and  accuracy  on 
that  account. 

Until  you  have  read  this  article,  you  may  be 
under  the  impression: 

That  sale  is  the  only  sort  of  infringement. 
This  is  not  the  case. 

That  an  inventor  can  continue  to  manufac- 
ture his  own  invention  after  selling  his 
patent.   Not  so. 

That  joint  owners  must  split  fifty-fifty.  No 
such  thing. 

That  it  is  wise  to  hire  a  patent  lawyer  on  a 
contingent  fee  basis. 
Quite  the  contrary. 

It  is  very  agreeable  to  have  some  of  the 
prevailing  "mysteries"  of  the  patent  game 
clearly  exposed  and  explained.  We  commend 
this  article,  and  the  three  in  the  series  which 
precede  it  (April-June,  1923),  to  all  our  readers 
who  have  even  the  slightest  glimmer  in  the 
back  of  their  minds  of  an  idea  which  might 
some  day  be  developed  into  an  invention  worth 
patenting. — The  Editor. 


of  your  American  application.  The  Con- 
vention is  a  treaty  between  most  of  the  civilized 
countries  of  the  globe,  whereby  an  inventor 
will  not  be  penalized  because  of  the  publication 
or  use  of  his  invention  within  a  period  of  12 
months  from  the  filing  of  his  first  patent  ap- 
plication. Under  the  Convention,  an  applicant 
is  safeguarded  for  one  year  from  the  date  of 

filing  his  first  patent 
application;  and,  so 
long  as  he  files  foreign 
applications  (in  the 
countries  party  to  the 
Convention)  within  12 
months  from  the  date 
of  filing  his  first  case, 
his  foreign  applica- 
tions will  be  immune 
from  attack  on  the 
ground  of  any  publi- 
cation or  use  of  the 
invention  that  may 
have  taken  place  in 
the  interim. 

In  the  United  States 
the  date  of  conception 
of  the  invention  is 
what  counts,  but  in 
practically  all  foreign 
countries  the  applicant 
must  stand  or  fall  by 
his  filing  date.  Thus 
in  most  foreign  coun- 
tries, a  published  de- 
scription or  public  use 
of  an  invention  prior  to 
thefiling  of  anapplica- 
tion  will  forever  prevent  a  patent,  unless  the 
inventor  gets  in  under  the  Convention.  In 
some  of  these  countries  the  publication  must 
be  local,  but  in  others  a  foreign  publication  will 
bar. 

In  case  you  do  not  wish  patent  protection 
abroad,  but  merely  wish  the  field  left  clear  for 
yourself,  you  can  prevent  others  from  obtaining 
a  valid  patent  on  your  invention,  by  publishing 
a  description  thereof  in  the  countries  in  question. 
This  description  should  be  full  enough  to  enable 
any  skilled  person  to  duplicate  the  device. 

In  considering  the  foreign  field,  bear  in  mind 
that  if  no  publication  or  use  has  taken  place, 
a  valid  patent  can  be  obtained;  but  that 
otherwise  a  valid  patent  is  possible  only  under 
the  Convention.  An  invalid  patent,  however, 
is  better  than  none. 


208 


Radio  Broadcast 


The  cost  of  patent  proceedings  varies  greatly 
in  foreign  countries,  and  is  complicated  by  the 
cost  of  translations,  patent  taxes  and  "work- 
ings," none  of  which  exist  in  America.  Of 
course,  different  firms  charge  different  amounts, 
but  the  following  represents  a  fair  average. 

Translation,  one  dollar  per  hundred  words  in 
most  countries,  but  running  as  high  as  three- 
fifty  in  some.  Drawings,  five  or  ten  dollars  a 
sheet.  Fees  and  legal  services,  from  forty 
to  two  hundred  dollars,  depending  on  the 
country. 

In  most  countries,  patents  are  subject  to  an 
annual  tax,  usually  starting  either  immediately 
on  filing,  or  immediately  on  issuance, 
or  a  few  years  thereafter,  and  gradu-  y^C- 
ally  increasing  during  the  life  of  the 
patent.     Non-payment   forfeits   the  ppjSIp 
patent.    In  some  countries,  there  is  iSps*** 
merely  an  extension  fee  required,  once  \*m&& 
in  the  case  of  14-year  patents,  or  twice 
in  the  case  of  20-year  patents.   A  few, 
notably  Canada  and  some  Latin  American 
countries,  have  no  tax. 

In  nearly  all  foreign  countries,  no  search,  or 
at  most  a  mere  perfunctory  examination,  is 
made  by  the  patent  office.  The  patent  is  ad- 
vertised, and  if  no  objection  is  filed  within  a 
certain  period  of  time,  it  issues  as  a  matter  of 
course.  But  Canada,  Germany,  and  Great 
Britain  proceed  by  office-action  and  amend- 
ment, very  much  as  does  the  United  States. 
Some  countries,  in  the  case  of  applications 
under  the  Convention,  require  the  filing  of 
copies  of  all  American  actions  and  amend- 
ments. 

In  nearly  all  foreign  countries,  the  patentee 
must,  within  a  certain  number  of  years,  com- 
mence the  local  manufacture  of  his  invention 
on  a  sufficient  scale  to  satisfy  the  local  de- 
mand; as  otherwise  the  patent  will  become 
void.  This  is  called  "working. "  But  in  some 
of  these  countries,  a  "nominal  working"  will 
do.  This  consists  in  advertising  for  someone  to 
build  your  invention,  and  then  in  the  rare 
eventuality  of  someone  taking  you  up,  making 
your  terms  too  hard  for  him.  Or  in  some  coun- 
tries, it  is  sufficient  to  mark  your  patent  "license 
of  right,"  which  means  that  you  will  license 
any  one  who  applies.  This  may  sound  danger- 
ous; but  in  Canada,  out  of  all  the  hundreds  of 
patents  so  marked,  only  one  such  license  has 
ever  been  required. 

Some  countries,  notably  Canada,  prohibit 
the  importation  of  the  patented  article  by  the 


patentee,  under  penalty  of  forfeiture  of  his 
patent.  But  the  law  is  usually  satisfied  by 
Canadian  manufacture  of  the  parts  vital  to  the 
patented  feature,  American  manufacture  of  the 
rest,  and  assembly  in  Canada.  Similar  acts  will 
also  satisfy  the  working  requirements  of  most 
countries. 

In  many  British  colonies,  a  British  patent 
can  be  registered  at  any  time  during  its  life, 
and  thereby  becomes  effective  locally  for  the 
rest  of  its  duration.  A  similar  rule  exists  in 
certain  Danish  and  United  States  colonies.  But 
in  a  very  few  British  colonies,  local  use  or 
publication  will  bar  filing.  And  in  another 
very  few,  use  abroad  by  others  than  the 
jjUK     inventor  will  bar  filing. 

The  life  of  a  foreign  patent  varies 
QjffiffBn  from  five  years  in  some  countries  to 
*^y/f^j\  twenty-one  years  in  others,  the  pre- 
'/y^  'J  vailing  period  being  fourteen  or  fifteen 
Wgffir  years. 

I  strongly adviseany inventoragainst 
foreign  patents,  unless  he  is  backed  by  a  corpora- 
tion sufficiently  affluent,  pugnacious,  and  liberal 
to  defend  his  rights,  or  unless  the  invention  is 
epoch-making  (which,  unfortunately,  most 
inventors  consider  all  their  "brain-children" 
to  be).  For  it  is  a  comparatively  simple  matter 
for  a  determined  local  competitor  to  upset 
the  patent  of  an  absentee. 

A  large  part  of  these  articles  has  consisted  in 
the  puncturing  of  popular  fallacies.  Therefore 
what  more  appropriate  way  is  there  for  con- 
cluding the  series  than  to  give  a  list  of  deadly 
parallels  setting  forth  each  of  the  prevailing 
misconceptions;  and,  in  contrast  to  each,  the 
truth.  This  list  will  follow  as  closely  as  possible 
the  order  of  the  preceding  text,  to  which  the 
reader  can  refer  for  more  detailed  enlighten- 
ment.* 
The  deadly  parallels  are: 

1.  That  the  ownership  of  a  valid  patent  is 
a  guaranty  of  your  right  to  manufacture  the 
patented  article.  On  the  contrary,  you  are  more 
than  likely  to  be  barred  by  at  least  one  earlier 
patent. 

2.  That  sale  is  the  only  sort  of  infringe- 
ment. On  the  contrary,  manufacture  is 
infringement,  and  use,  even  by  an  innocent 
purchaser  of  a  machine,  may  also  infringe. 

3.  That  no  damages  can  be  collected  for  an 


*The  three  preceding  articles  in  this  series  of  four,  are: 
"What  Good  is  a  Patent?"  in  the  April  number;  "What 
Can  Be  Patented?"  in  the  May  number;  and  "Protecting 
Your  Invention",  last  month. 


Putting  Your  Patent  Across 


infringement  which  doesn't  make  money. 
On  the  contrary,  the  patentee  can  collect  three 
times  what  he  would  have  made,  if  you  had  not 
taken  away  his  trade. 

4.  That  use  purely  for  amusement  is  not 
infringement.  On  the  contrary,  it  is  infringe- 
ment, if  the  device  is  an  amusement  device. 

5.  That,  if  you  invent  something  first,  no 
subsequent  inventor  can  prevent  you  from 
using  your  own  invention.  On  the  contrary, 
he  may  quite  likely  obtain  a  patent  which  will 
be  held  valid,  in  spite  of  proof  of  your  earlier 
conception,  and  thus  may  enjoin 
you  from  using  your  own  device. 

6.  That  joint  owners  of  a  patent 
cannot  act  alone.  On  the  contrary, 
any  one  of  them  can  issue  a  valid 
license  under  their  patent. 

7.  That  joint  owners  must  split 
fifty-fifty .  On  the  contrary,  neither 
of  two  co-owners  is  responsible  to  the 
other,  in  the  absence  of  an  express  agreement. 

8.  That  the  invention  of  a  technical  em- 
ployee, invented  in  the  course  of  his  employ- 
ment, belongs  to  his  employer.  On  the  con- 
trary, there  are  many  situations  in  which  it 
does  not,  even  though  the  invention  is  applic- 
able to  the  employer's  busine'ss. 

9.  That  it  is  a  harmless  courtesy  to  in- 
clude your  helper  or  your  boss  as  a  joint 
inventor.  On  the  contrary,  this  may  invali- 
date your  patent. 

10.  That  an  assignment  of  all  future  in- 
ventions is  void,  unless  it  contains  a  time 
limit.  On  the  contrary,  a  limit  as  to  subject 
matter  is  equally  effective. 

11.  That  an  inventor  can  continue  to 
manufacture  his  own  invention,  even  after 
selling  his  patent.  On  the  contrary,  a  patent, 
once  sold,  is  gone  forever. 

12.  That  there  is  some  magic  in  having  the 
inventor's  first  drawing  bear  the  signatures  of 
two  witnesses  and  be  attested  by  a  notary. 
On  the  contrary,  the  real  requirement  is  the 
assurance  that  at  least  one  outsider  has  under- 
stood the  invention  on  the  date  in  question,  and 
will  so  testify  convincingly  in  court. 

13.  That  when  some  prior  patent  is  cited 
against  your  application,  you  must  execute 
some  sort  of  paper  admitting  its  validity. 
On  the  contrary,  you  can  avoid  the  citation  by 
showing  either  that  your  invention  does  not 
come  under  it,  or  that  your  invention,  although 
subsidiary  to  the  other,  yet  constitutes  an  im- 
provement upon  it. 


14.  That  the  mention  of  some  prior  patent 
in  a  printed  specification  shows  that  some  such 
paper,  as  mentioned  above,  has  been  filed. 
On  the  contrary,  there  is  no  such  thing.  This 
mention  is  usually  either  for  the  purpose  of 
shortening  your  description  by  referring  to 
some  well-known  prior  device,  or  for  the  pur- 
pose of  obtaining  the  benefit  of  the  earlier 
filing  date  of  some  other  application  of  your 
own. 

15.  That  patent  office  tactics  are  no  concern 
of  the  inventor.    On  the  contrary,  many  a 

patent  proceeding  has  been  spoiled 
through  the  failure  of  the  inventor  to 
keep  intelligently  in  touch  with  the 
different  moves  which  his  attorney 
i  was  making. 

16.  That  there  is  something 
wonderful  in  a  lawyer's  being 
able  to  guarantee  the  securing  of  a 
patent.  On  the  contrary,  1  my- 
self will  guarantee  to  get  any  one  a  patent 
on  almost  anything,  old  or  new;  but  1  will 
not  guarantee  that  this  patent  will  be  worth 
a  nickel. 

1 7.  That  it  is  wise  to  hire  a  patent  lawyer  on 
a  contingent-fee  basis.  On  the  contrary,  a 
patent  application  is  unlike  a  damage  suit, 
for  in  the  case  of  a  patent  it  is  impossible  to 
measure  the  value  of  the  results.  A  contingent- 
fee  patent  case  is  likely  to  be  carelessly  han- 
dled. 

18.  That  a  clear  abstract  of  title  means  a 
clear  title.  On  the  contrary,  there  may  be 
outstanding  a  valid  license,  which  has  not  been 
recorded  in  the  Patent  Office. 

19.  That,  at  least,  the  ownership  of  a  valid 
patent  clears  you  of  all  prior  patents  which 
were  not  cited  against  your  application.  On 
the  contrary,  your  patent  may  infringe  some 
patent  of  which  you  have  never  heard,  and  yet 
may  be  clear  of  many  which  were  cited  against 
it. 

20.  That  the  patent  examiner  exhausts  the 
prior  art.  On  the  contrary,  patent  examiners  are 
overworked  and  underpaid,  and  often  issue 
a  patent  which  is  absolutely  void  because  of 
some  overlooked  prior  patent  which  is  directly 
in  point. 

In  general,  remember  that  nearly  every  bit  of 
current  belief  about  patent  law  is  decidedly 
not  so.  The  more  that  anyone  says,  "Oh, 
everybody  knows  that!",  the  wiser  it  will  be 
for  you  to  run  to  some  authoritative  book  and 
look  it  up! 


The  Set  the  Boy  and  His  Dad  Built 


By  ARTHUR  N.  KING 

(Dad) 


SAY,  Dad,  if  you  will  help  me  get  a 
radio  set,  I'll  stop  wanting  a  bicycle." 
Dad  said,  "All  right,"  and  so  the  work 
was  begun. 
The  boy  had  made  several  attempts 
at  winding  coils  and  finally  had  made  a  very 
good  loose  coupler  from  material  obtained  at  a 
five-and-ten-cent  store.  A  crystal  detector 
came  from  the  same  source.  The  boy  and  his 
younger  brother  found  some  long  poles  in  the 
woods  and  used  them  to  erect  an  antenna  about 
sixteen  feet  high  and  forty  feet  long.  A  good 
set  of  phones  completed  the  outfit  and  after 
some  strained  listening  the  boys  heard  a  bit  of 
code,  but  it  was  like  a  foreign  language  to  them. 

The  next  act  was  to  purchase  a  vacuum-tube 
socket,  a  rheostat,  grid  condenser,  variable  air 
condenser,  and  a  variometer.  Dad  made  up  a 
little  unit  containing  the  control  for  the  detec- 
tor filament;  etc.  Mother  contributed  a 
small  table  to  put  the  apparatus  on.  A  UV- 
200  detector  tube  and  five  flashlight  batteries 
were  then  bought,  the  latter  to  be  used  as  the 
22^-volt  B  battery. 

Dad  didn't  want  an  outdoor  antenna,  so  it 


was  up  to  him  to  provide  one  in  the  attic.  One 
night  the  two  boys  and  Dad  shed  most  of  their 
clothes,  donned  overalls  and  climbed  up 
through  a  trap  door  into  the  attic  which  was 
barely  four  feet  high  in  the  centre.  A  very  few 
boards,  nailed  here  and  there  over  the  joists 
which  held  the  ceiling  below,  made  a  precarious 


THE  SET 


footing,  or  rather  backing,  for  they  had  to 
move  around  on  their  backs  most  of  the  time. 
One  boy  held  the  lantern,  the  other  held  the 
wire,  and  Dad  nailed  up  the  insulators  and 
fastened  the  wire;  while  down  below  the  family 
dog,  Jakey,  cocked  one  ear  aloft  and  looked  as 
if  he  wanted  to  help  too.  Always  afraid  of 
putting  their  feet  through  the  plaster,  the  trio 
wriggled  and  squirmed,  pounded,  puffed,  and 
groaned  for  nearly  three  hours.  When  they 
crawled  down,  the  attic  was  well  dusted  and 
they  were  fit  only  to  get  into  the  bath  tub. 

The  next  night  Dad  fin- 
ished tacking  the  lead-in 
wire  through  a  closet  and 
along  the  baseboard  of  the 
boys'  room  to  where  the 
radio  table  was. 

A  kind  neighbor  came  in 
with  a  spare  A  battery  which 
he  said  they  could  use  until 
tney  were  able  to  get  one  of 
their  own.  This  Good 
Samaritan  brought  a  news- 
paper with  him,  which 
showed  a  diagram  of  the 
hook-up  to  be  used.  Dad 
was  mighty  glad  that  this 
was  the  hook-up,  for  he  has 
always  felt  that  there  were 
as  many  hook-ups  as  there 
are  radio  fans,  maybe  more, 
for  some  fans  seem  to  be 
constantly  doping  out  new 
ones. 


The  Set  the  Boy  and  His  Dad  Built 


2 1  r 


the  good  Samaritan's  hook-up 

When  the  stuff  had  been  fastened  to  the 
table  top,  the  Good  Samaritan  studied  his 
treasured  hook-up  and  fastened  bits  of  wire 
here  and  there  on  the  apparatus  and  finally 
connected  it  to  the  batteries.  The  ground  wire 
was  attached  to  a  radiator.  Then,  oh  critical 
moment,  he  put  on  his  headset  and  began  to 
move  different  things  while  he  listened  for 
something.  The  bulb  lighted  but  it  wouldn't 
talk.  What  could  the  matter  be?  Dad  and 
the  G.  S.  compared  the  hook-up  with  the  dif- 
ferent wire  connections  and  found  a  disagree- 
ment between  them.  Changing  the  wires  he 
listened  again.  Suspense  .  .  .  WAAJ ! 
Hurrah!  Twenty  watts,  eleven  miles  away 
and  our  set  was  getting  it.  Then  he  tuned  in 
WNAC,  Boston,  and  all  hands  called  it  a  night 
and  went  to  bed. 

Two  days  later,  Boy,  Dad,  and  Company 


STATES  HEARD  FROM  WALTHAM,  MASS. 

picked  up  "the  Voice  of  the  Air"  at  WGI, 
Medford  Hillside,  Mass.,  and  after  more  than 
two  weeks  heard  WJZ  and  WOR  in  Newark, 
N.  J.  Then  a  few  days  later  came  KDKA, 
"the  Pioneer  Broadcasting  Station,"  over  in 
Pittsburgh,  and  oh  boy! — what  a  queer  feeling 
they  had  when  they  thought  of  its  being  so  far 
away!    Did  you  ever  have  that  feeling? 


THE  BOY 

Dad  was  becoming  handier  at  the  tuning  and 
he  added  WFAU  and  then  WGY,  "the  Gener- 
ous Electric  Company"  in  Schenectady.  Then, 
from  the  G.  E.  factory,  he  skipped  over  to 
school  in  Troy,  WHAZ,  and  then  back  nearer 
home  to  WCN,  Clark  University. 

Hearing  about  the  electric  light  socket  at- 
tachments that  could  be  used  for  an  antenna, 
the  boy  bought  one  and  it  has  been  in  use  ever 
since. 

Don't  forget  that  this  was  the  boy's  set,  but 
Dad  appointed  himself  chief  operator  and 
was  on  the  job  almost  every  evening.  The 
younger  lad  contributed  another  pair  of  phones, 
so  that  by  dividing  up  the  ear  pieces,  four  peo- 
ple could  listen  at  one  time,  as  shown  in  the 
etching  of  the  family  quartet. 

The  family  next  became  acquainted  with 
the  great  public  ser- 
vice company  at 
WEAF,  New  York 
City.  Then  up  the 
Hudson  a  bit  was 
WRWin  that  town 

which  reminds  one  the  f.  q. 


212 


Radio  Broadcast 


of  Washington  Irving.  Skipping  east  again 
they  stopped  to  listen  to  WBZ,  Springfield, 
and  then  a  big  jump  south  landed  them  with  the 
navy  at  NOF  in  the  District  of  Columbia.  A 
step  backward  and  they  heard  that  noble  organ 
at  WOO  in  the  store  of  one  of  the  great  mer- 
chants, in  Philadelphia.  Then  one  Sunday 
evening,  faintly  came  the  words,  "WDAP, 
Chicago!"  If  getting  KDKA  had  made  Dad 
feel  queer,  think  of  his  feelings  now.  He  almost 
slipped  off  his  chair,  he  was  so  excited.  With  his 
hands  off  the  dials,  there  was  silence,  with  his 
hands  touching  the  dials  came  music  from 
WDAP. 

"  Hello  boy,  wake  up ! " 
"What's  matter,"  muttered  the  boy. 
"Got  Chicago!  Put  the  phones  on  and 
listen!"  At  this  a  sleepy  boy  rolled  out  of 
bed,  slipped  on  the  phones  and  heard  Chicago 
while  Dad  held  the  dials.  What  bliss;  and  the 
boy  had  wanted  to  change  the  hook-up  because 
for  a  long  time  we  couldn't  hear  WJZ! 

Skipping  back  to  rugged  New  England  they 
heard  the  voice  of  the  Green  Mountain  State 
from  WLAK;  and  then  the  Courier-Journal, 
WHAS,  called  then  to  Kentucky,  the  old  hunt- 
ing ground  of  Daniel  Boone.  What  boy 
doesn't  like  to  read  about  him?  While  they 
are  thinking  about  hunting  and  Indians,  Pon- 
tiac  comes  to  their  minds  as  they  hearWWJ 
talking  from  Detroit.  Back  down  in  Phila- 
delphia, another  merchant  announced  WIP, 
further  south  they  listened  to  WBT,  in  Char- 
lotte, North  Carolina.  Returning  a  bit  they 
heard  "  Hello  Uncle  Johnny,  Hello  Everybody" 
at  Station  WQAA.    WRP  in  Camden,  N.  J. 

reminded  then  of  the  school- 
days history  of  the  Revolu- 
tionary War,  and  then  in  a 
few  minutes  they  were  on 
the  banks  of  the  Father  of 
the  Waters  listening  to  the 
call  of  WOC,  "Where  the 
West  Begins,  and  the  Land 
Where  the  Tall  Corn  Grows,"  and  the  name  of 
a  school  having  a  queer  name  which  they  didn't 
understand. 

They  paused  to  breathe  again,  for  they  had 
broken  their  distance  record.  The  next  night 
from  KYW  in  Chicago  came  the  strains  of  that 
splendid  grand  march  from  the  opera  "Aida," 
played  in  the  Chicago  Opera  House.  The 
following  evening  they  stopped  in  the  midst 
of  the  machine  tool  industry  and  heard  WLW, 
Cincinnati,   Ohio.    Skipping  up   to  Buffalo 


they  heard  WGR.  WGM,  "The  Voice  of  the 
South"  calling  from  Atlanta,  Georgia,  re- 
minded them  of  Sherman's  March  to  the  Sex. 
Moving  the  condenser  one  degree  carried  them 
to  a  foreign  shore,  where  a  voice  said,  "  Habana, 
Cuba."  Shades  of  the  buccaneers!  Dad  and 
his  better  half  nudged  each  other  and  held  fast. 

An  announcement  in 
English  and  one  in 
Spanish,  then  a  fine 
piece  of  orchestral 
music  followed  by 
the  call  PWX,  as- 
sured them  that  it 
was  indeed  a  foreign 
'  land.  Fifteen  hun- 
dred miles  away,  and 
they  could  hear  the 
talking  and  music. 
Doesn't  the  wonder  of  it  almost  take  your 
breath?  Oh  yes,  they  have  a  clock  down  at 
PWX  and  you  can  hear  it  tick. 

The  next  evening  the  boy  made  his  farthest 
West  by  hearing  WHB,  Kansas  City,  Missouri, 
in  the  heart  of  America. 

Returning  east  once  more  the  boy  and  his 
Dad  heard  WHN  on  Long  Island.  Next  they 
were  out  by  the  Mississippi  listening  to  KSD  in 
St.  Louis  and  were  re- 
minded of  Churchill's  story 
"The  Crisis."  Then  the 
"Wave  from  Lake  Erie," 
WJAX,  broke  on  their  ears 
and  they  remembered 
about  the  battle  of  Lake  Erie  which  took  place 
at  Put-in-Bay,  fifty  or  sixty  miles  west  of  Cleve- 
land. Ever  been  to  Put-in-Bay?  There  are 
some  mighty  interesting  caves  there  and  one  of 
them  is  said  to  have  been  a  hiding  place  of 
Perry's. 

So  they  go,  skipping  here  and  there,  making 
the  acquaintance  of  places  far  from  home, 
studying  maps  and  listening  to  people  whom 
they  had  never  expected  to  hear  but  are  usually 
glad  to  have  heard.  They  hear  the  turn,  turn, 
turn  of  the  fox-trot,  the  melody  of  Grand 
Opera,  a  talk  about  the  Everglades,  politics, 
books,  medicine,  or  clothing.  All  Dad  knows 
about  a  boxing  match  came  from  a  bout  at 
Madison  Square  Garden.  One  night  there  was 
the  story  of  the  Creation  told  in  an  ancient 
Indian  language  so  old  that  only  one  man  in 
the  world  could  now  speak  it.  Subjects  in- 
numerable, and  a  whole  education  for  those 
who  have  the  time  to  listen. 


The  Set  the  Boy  and  His  Dad  Built 


213 


Broadcast  reception  is  very  erratic.  It  is 
not  always  the  powerful  stations  which  have 
been  heard  through  the  greatest  distance.  One 
night  they  picked  up  WHAK,  a  twenty-watt 
station  570  miles  away  in  West  Virginia  and  the 
next  night  Dad  listened  to  WBL,  a  fifty-watt 
station,  1 545  miles  away  in  Anthony,  Kansas. 

Do  you  who  live  in  the  Central  States  ever 
stop  to  think  what  a  fortunate  location  you  en- 
joy? You  can  just  tune  in  to  the  different  sta- 
tions in  every  direction  around  you,  while  radio 
fans  on  the  Eastern  edge  of  the  country  can  lis- 
ten-in on  only  half  of  the  horizon,  for  not  many 
people  have  stations  that  can  get  Europe. 

One  night,  the  boy  started  for  bed  and  some 
time  later,  Dad,  not  having  heard  the  usual 
cheery  "Good-night,"  went  up  to  investigate. 
Lo  and  behold,  the  boy  had  a  regular  loud- 
speaker working.  He  was  stretched  out  on  two 
chairs,  with  his  feet  on  the  radiator,  phones  on 
his  ears,  sound  asleep  and  snoringlikea  saw-mill. 

Ma  wanted  to  under- 
stand  code  and  now  each 
evening  at  suppertime, 
while  preparing  the  even- 
ing meal,  she  keeps  one  eye 
on  the  clock  so  as  not  to  be  tardy  at  the  receiver 
when  Uncle  Jack  starts  sending  slow  code  from 
WGI.  Now,  when  Dad  and  Ma  are  listening 
to  a  concert  and  code  comes  slamming  in  to 
the  exclusion  of  all  else,  Ma  doesn't  mind  at  all, 
but  listens  to  the  dah-dit-dah  and  smiles  while 
Dad  sits  by  in  a  spirit  of  resignation. 

Did  you  ever  have  a  radio  ghost  in  your 
house?  One  night  Dad  was  roused  from  sound 
slumber  by  Ma,  who  said,  "  There's  a  queer 
noise  downstairs."  Dad  didn't  hear  any- 
thing for  a  few  moments,  then  all  at  once  there 
came  the  sound  of  a  telegraph  ticker;  a  few  taps 
and  then  silence,  a  few  more  taps  and  silence. 
The  boy  had  a  practice  set,  but  he  was  sound 
asleep,  so  Dad  made  a  trip  downstairs  to  in- 
vestigate. On  a  table  was  a  dry-cell  lying  near 
a  telegraph  ticker.  Suddenly,  while  Dad  stood 
still,  looking  and  listening,  the  instrument  began 
clicking.  Not  a  hand  near  it.  A  few  taps  and 
then  silence.  Dad  thought  it  about  time  for 
the  ghost  to  go  to  bed,  so  he  carefully  looked  the 
outfit  over  and  found  that  while  there  was  one 
wire  connected  between  the  battery  and  the 
ticker,  the  second  wire  was  disconnected  at 
one  end  but  lying  in  such  a  way  that  a  slight 
vibration  of  the  building  would  cause  the  wire 
to  make  a  contact  and  the  ticker  would  mo- 
mentarily operate.    Removing  the  wires  laid 


the  ghost,  and  Ma  and  Dad  slumbered  quietly 
the  rest  of  the  night. 

Dad  usually  joins  the  boy  at  the  radio  set  for 
a  while  every  night  before  retiring.  No  matter 
how  sleepy  or  tired  he  is,  a  few  minutes'  listen- 
ing-in brightens  him  right  up,  but  oh  how 
aggravating  are  those  faint  indistinct  announce- 
ments that  can't  be  brought  in!  Just  aggra- 
vating enough  to  make  Dad  want  some  radio- 
frequency  amplification.  You  will  see  by  the 
photo  of  the  set  that  the  controls  are  in  such 
positions  as  to  cause  a  great  deal  of  trouble  from 
body  capacity.  This  was  avoided  to  a  certain 
extent  by  slipping  a  brass  tube  about  two  and 
one-half  inches  long  over  the  detector  bulb  and 
connecting  the  brass  to  the  ground  wire.  This 
arrangement  made  the  set  more  stable,  but 
several  stations  previously  heard  are  now 
dumb,  so  Dad  removed  the  brass  tube  in  order 
to  have  another  try  at  those  stations.  From 
the  operation  of  the  boy's  receiver,  Dad  is 
firmly  convinced  that  the  best  way  to  avoid 
trouble  from  body  capacity  is  to  use  long 
shafts  on  the  controls,  preferably  of  nonmetallic 
material.  A  friend  of  Dad's  extended  the 
shaft  of  a  grid  variometer  and  placed  on  it  a 
talking  machine  disc  record  for  a  dial.  This 
arrangement  gave  excellent  results  as  it  avoided 
the  body  capacity  effects,  and  the  large  dial 
gave  a  very  sensitive  control  of  the  instrument, 
permitting  the  tuning-in  of  stations  whose 
broadcast  was  formerly  nothing  but  noises. 


THE  BEST  WAY  TO  AVOID  BODY  CAPACITY 

Of  the  calls  heard,  the  worst  mix-up  was 
when  two  stations  were  alternating  their  pro- 
grams and  announcements:  WHN,  Ridge- 
wood,  Long  Island,  and  WEAG,  Edgewood, 
Rhode  Island.  The  two  kinds  of  wood  and 
islands  certainly  had  everyone  puzzled. 


R.  F.  Amplification  Without  Distortion 

or  Reradiation 


By  EDWARD  LINDLEY  BOWLES 

Instructor  in  Electrical  Communication.  Massachusetts  Institute  of  Technology- 
Many  beginners  have  been  intrigued  by  the  claims  made  for  various  involved  circuits.    For  the 
novice,  radio  frequency  is  complicated,  and  its  use  does  not  always  result  in  greater  range  with  a  home- 
made outfit. 

You  will  do  well  to  attempt  R.  F.  amplification  only  after  you  have  mastered  a  regenerative  receiver 
and  A.  F.  amplifier.  This  is  especially  true  since  the  change  in  the  broadcasting  wavelengths  has  been 
in  effect,  because  few  transformers  will  cover  satisfactorily  a  range  from  220  to  550  meters. 

We  do  not  wish  to  discourage  the  use  of  radio  frequency,  but  we  do  wish  •  to  discourage  indiscrimi- 
nate buying  which  results  in  disappointment  to  the  buyer  and  ultimate  reduction  of  sales  for  the  dealer. 
— The  Editor. 


TO-DAY  the  question  of  radio-fre- 
quency amplification  is  uppermost  in 
the  minds  of  both  the  amateur  and 
the  broadcast  listener.  Since  the 
new  allocation  of  wavelengths,  the 
broadcast  receiving  set  is  not  confined  in  its 
operation  to  wavelengths  in  the  neighborhood 
of  360  and  400  meters,  but  it  must  range  from 
as  high  as  550  meters  to  as  low  as  220  meters. 

Volumes  have  been  written  on  radio- 
frequency  amplification,  in  which  proponents  of 
particular  methods  have  been  eager  to  convince 
readers  of  the  merits  of  their  choice  circuits. 
Yet,  many  of  those  who  have  attempted  to 
construct  their  own  radio-frequency  amplifiers 
for  short  wavelength  work  have  been  disap- 
pointed in  the  results.    This  is  due  to  an  in- 


FIG. 


R.  F.  amplifier  showing  a  tuned  primary  transformer 


adequate  knowledge  of  the  functioning  of  the 
units  employed,  and  the  natural  tendency  to 
judge  as  "best"  the  circuits  bearing  high-sound- 
ing names  and  blessed  with  good  press  agents. 

Many  so-called  radio-frequency  amplifying 
transformers,  or  amplifying  devices,  which  have 
been  advertised  for  the  shorter  wavelengths, 
have  proved  to  be  poor.  In  fact,  the  writer 
has  found  that  in  some  cases  so-called  short 
wavelength  radio-frequency  amplifying  devices 
have  done  more  harm  than  good.  It  seems 
only  fitting  that  since  radio  broadcasting  has 
reached  a  point  where  many  wavelengths  must 
be  used  in  order  to  relieve  congestion,  and  since 
these  wavelengths  must  be  "short, "  the  broad- 
cast public  should  have  a  general  idea,  at  least, 
as  to  why  there  is  likely  to  be  difficulty  in  apply- 
ing only  general  ideas  of 
radio-frequency  amplifica- 
tion to  circuits  which  they 
have  already  constructed  or 
which  they  propose  to  con- 
struct, in  order  that  these 
difficulties  may  be  avoided. 

Technical  analysis  has 
shown  that  R.  F.  amplifica- 
tion is  more  effective  than 
A.  F.  in  bringing  in  distant 
signals.  Of  course,  if  a  signal 
is  too  weak,  no  matter  how 
good  the  receiving  set  may 
be,  the  signal  will  not  come 
in.  In  other  words,  there 
must  be  a  slight  disturb- 
ance, at  least,  in  the  neigh- 
borhood of  the  antenna  or 
loop,  in  order  that  the  re- 


R.  F.  Amplification  Without  Distortion  or  Reradiation 


215 


ceiving  apparatus  may  be  affected.  The  an- 
tenna is  capable  of  grasping  more  of  the  energy 
sent  out  in  the  form  of  waves  than  is  the  loop. 
As  a  consequence,  much  more  amplification  is 
necessary  where  a  loop  is  used.  In  either  case, 
where  a  single  tube  is  used,  and  where  signals 
are  not  coming  in  strong,  or  where  distant  sig- 
nals can  not  be  heard,  one  is  confronted  with 
the  problem  of  introducing  some  sort  of  am- 
plification. One  can  use  audio-frequency — a 
common  practice — or  radio-frequency.  Audio- 
frequency has,  of  course,  become  very  popular, 
and  many  receiving  sets  are- now  equipped  with 
a  stage  or  two  of  such  amplification.  Two 
stages  of  audio-frequency  amplification,  a  re- 
generative tuner,  and  a  detector  tube,  make  the 
most  popular  combination.  If  a  loud  speaker 
is  used,  the  amount  of  energy  delivered  by  the 
two  stages  of  amplification  is  not  always  suffi- 
cient to  operate,  especially  in  large,  open  places, 
so  that  in  some  cases  an  additional  amplifier, 
usually  of  three  tubes,  is  used  to  furnish  suffi- 
cient energy  to  operate  the  loud  speaker 
diaphragm. 

It  has  been  shown  by  actual  analysis  that  the 
detector  tube  is  comparatively  more  sensitive 
when  it  is  affected  by  a  strong  signal  than  when 
it  is  affected  by  a  weak  one.  In  fact,  the  effect 
which  signals  can  produce  on  a  detector  is 
probably  roughly  proportional  to  their  square. 
That  is,  if  the  intensity  of  the  impressed  signal 
is  doubled,  its  effect  will  be  quadrupled.  It 
is  evident,  then,  that  any  amplification  of  the 
incoming  signal  which  can  be  made  before  it 
reaches  the  detector  tube  will  have  an  effect 
far  greater  than  the  same  amount  of  amplifica- 
tion of  the  signal  after  it  has  affected  the  de- 
tector tube.  Roughly,  a  radio-frequency  (volt- 
age) amplification  of  10  has  the  same  effect  as 
an  audio-frequency  (voltage)  amplification  of 
100.  It  is  for  this  reason  that  so  much  effort 
has  been  made  to  devise  apparatus  which 
would  properly  amplify  signals  at  radio  fre- 
quency. 

The  design  of  radio-frequency  amplifying 
circuits  for  the  longer  wavelengths  is  a  com- 
paratively simple  matter.  The  long  wave- 
lengths correspond  to  the  lower  frequencies, 
and  it  is  much  easier  to  build  circuits  to  behave 
properly  at  low  frequencies  than  it  is  to  build 
them  to  behave  properly  at  high  frequencies. 

Various  radio-frequency  amplifiers  were  dis- 
cussed in  two  articles  by  Mr.  Arthur  H.  Lynch 
in  the  March  and  April  issues  of  Radio  Broad- 
cast.   Ordinarily,  tremendous  amplification  is 


FIG.  2 


An  air-cored  transformer-coupled  amplifier 
with  a  potentiometer  to  control  the  R.  F.  tube 

obtained  by  regeneration;  and  even  greater 
amplification  can  be  obtained  by  super-regen- 
eration; but,  at  the  same  time,  regeneration 
introduces  distortion,  and  produces  reradiation. 
Improperly  adjusted  regenerative  sets  may 
make  a  particular  locality  untenable  for  others 
who  are  attempting  to  receive,  for  the  latter,  in 
making  their  own  adjustments,  will  be  greeted 
with  a  series  of  variable  howls  and  squeals 
which  are  anything  but  enjoyable.  Regenera- 
tion can  be  used  in  conjunction  with  radio- 
frequency  amplification,  however,  so  as  to 
prevent  reradiation. 

The  greatest  difficulty  in  radio-frequency 
amplification  is  to  obtain  this  amplification 
without  regeneration.  Many  of  the  coupled 
radio-frequency  amplifiers  for  short  wave- 
lengths operate  as  regenerative  circuits,  so  that 
after  all,  the  amplification  in  this  case  is  deter- 
mined by  regeneration  and  not  by  what  we 
would  ordinarily  term  direct  tube  amplification 
— due  to  the  amplification  factor  of  the  tube 
itself.  An  example  of  a  tuned  radio-frequency 
amplifier,  as  produced  by  a  commercial  com- 
pany at  the  present  time,  is  shown  in  Fig.  1. 
This  amplifier  is  constructed  with  a  set  of  four 
output  coils  so  that  it  operates  at  from  150  to 
3,000  meters.  The  radio-frequency  amplifier 
is  coupled  to  the  detector  tube.  The  grid  bias 
voltage  is  obtained  by  means  of  the  stabilizer 
shown  in  the  figure.  This  stabilizer  makes  it 
possible  to  prevent  the  amplifier  from  oscillat- 
ing. When  the  arrow  is  at  the  extreme  right, 
the  grid  of  the  tube  is  most  positive,  and  when 
it  is  at  the  extreme  left,  the  grid  is  most  nega- 
tive. As  the  arrow  moves  toward  the  left,  the 
circuit  is  more  and  more  likely  to  oscillate.  A 
radio-frequency  amplifier  should  operate  with- 


Radio  Broadcast 


out  regeneration  and  without  oscillating. 
Those  who  have  operated  a  regenerative  re- 
ceiver know  that  as  the  tickler  is  moved  up  to  a 
certain  point  no  sound  is  heard,  but  suddenly 
a  definite  point  is  reached  where  a  click  is  heard 
in  the  telephones.    This  click  is  due  to  the  fact 


fig.  3 

c       A  schematic  circuit  showing 
-r     how  a  condenser  and  an  in- 
ductance in  parallel  may  di- 
vide the  current 


that  the  tube  has  begun  to  oscillate  at  a  radio- 
frequency.  When  the  tube  oscillates,  the  cur- 
rent furnished  to  the  tube  by  the  B  battery 
changes  and  it  is  the  change  of  this  current 
through  the  receivers  that  produces  the  click. 
When  the  tickler  is  moved  still  further,  another 
click  will  be  heard.  This  second  click  indicates 
that  the  oscillations  have  ceased.  In  tuning-in 
a  station,  regeneration  is  obtained  (if  the  set- 
ting of  the  tuner  is  correct  for  the  particular 
station)  just  before  the  first  click  occurs.  If  a 
radio-frequency  amplifier  is  oscillating  at  a 
radio  frequency,  this  fact  can  be  detected  by 
touching  the  finger  to  the  grid  of  the  tube. 
If  oscillations  are  present,  they  will  be  stopped 
by  this  act  so  that  a  distinct  click  will  be  heard 
in  the  telephones.  This  is  not  the  proper  state 
of  a  radio-frequency  amplifier. 

Fig.  2  shows  a  simple  type  of  radio-frequency 
amplifier  involving  an  air  core  coupling  trans- 
former. The  operation  of  such  a  circuit  is 
very  difficult  at  short  wavelengths  because  the 
tubes  are  almost  bound  to  oscillate  unless  the 
potentiometers  shown  are  so  adjusted  that  the 
grids  of  the  tubes  are  positive.  When  the  grids 
are  positive,  the  possibility  of  oscillation,  and 
therefore  of  regeneration,  is  reduced,  but  it  will 
usually  be  found  that  under  these  conditions 
the  ordinary  radio-frequency  amplifier  is  not 
of  much  use.  In  other  words,  if  the  grids  are 
made  positive  and  then  are  slowly  made  nega- 
tive, in  the  act  of  tuning,  it  will  be  found  that 
the  operation  of  the  circuit  will  depend  upon 
a  critical  adjustment  of  the  potentiometers. 
This  means  that  the  circuit  is  operating  on  the 
border  of  oscillation;  that  is,  it  is  acting  as  a 
regenerative  circuit.  This  can  be  definitely 
determined  by  having  the  circuit  in  operation 
under  such  conditions  and  by  sliding  the 
potentiometer  dial  in  such  a  position  that  the 
grid  is  as  negative  as  possible  (that  is,  by  sliding 
the  potentiometer  to  the  extreme  left  in  the 


figure).  Under  these  conditions,  if  the  ampli- 
fier is  oscillating,  a  distinct  click  will  be  heard 
on  touching  the  grid  connections  of  either  tube. 

The  action  of  radio-frequency  circuits  may* 
be  understood  more  clearly  by  considering  some 
of  the  units  which  make  them  up.  For  in- 
stance, a  coil  of  wire  in  an  electric  circuit  offers 
no  more  opposition  to  the  flow  of  direct  current 
(that  is,  current  flowing  in  one  direction  only 
and  interchanging  in  value)  when  the  wire  is 
in  this  form  than  it  does  when  the  wire  is  un- 
wound. For  currents  which  alternate  in  direc- 
tion, the  situation  is  different.  The  higher  the 
frequency,  the  more  opposition  the  coil  offers 
to  the  flow  of  current. 

Further,  an  electric  condenser  is  made  up 
of  two  adjacent  conducting  surfaces  separated 
by  an  insulating  material.  It  does  not  allow 
any  direct  current  to  pass  through  it,  yet,  if 
an  alternating  voltage  is  impressed  on  a  circuit 
containing  a  condenser,  the  current  which 
flows  depends  upon  the  frequency.  The  higher 
the  frequency  of  the  alternations  of  the  im- 
pressed electric  force  or  voltage,  the  greater  the 
current.  Short  wavelengths  correspond  to 
high  frequencies.  For  example,  a  wavelength 
of  300  meters  represents  a  frequency  of  one 
million  cycles  a  second.  A  wavelength  of  100 
meters  represents  a  frequency  of  three  million 


FIG.  4 

A  schematic  diagram  showing  the  little  fixed  con- 
densers which  are  present  in  every  vacuum  tube 


cycles  a  second.  Keeping  these  facts  in  mind, 
the  result  can  be  illustrated  by  means  of  the 
circuit  shown  in  Fig.  3,  where  there  is  an  alter- 
nating current  generator  capable  of  producing 
an  electric  force  or  voltage  of  any  desired  fre- 
quency. If  the  frequency  is  very  low,  all  the 
current  will  flow  through  the  coil  L,  for  the 
loWer  the  frequency  the  less  will  be  the  opposi- 
tion which  the  coil  offers  to  the  flow  of  current 
through  it.  At  high  frequencies,  the  tendency 
of  the  current  will  be  to  flow  through  the  con- 
denser C,  for  the  higher  the  frequency  the 


R.  F.  Amplification  Without  Distortion  or  Reradiation 


217 


lower  will  be  the  opposition  which  the  con- 
denser offers  to  the  flow  of  current  through  it. 
It  is  possible,  then,  to  have  a  frequency  so  high 
that  much  of  the  current  will  be  passed  by  the 
condenser  C.  When  the  frequency  is  such 
that  the  opposition  offered  by  the  condenser  is 
practically  the  same  as  the  opposition  offered 
by  the  inductance,  then  the  circuit  is  said  to  be 
in  resonance.  Such  is  the  case,  for  example, 
when  the  parallel  circuit  of  Fig.  1,  made  up  of 
the  condenser  and  inductance,  is  properly  tuned 
to  a  particular  wave. 

A  very  small  capacity  may  have  a  very  harm- 
ful effect  at  high  frequencies.  In  the  case  of 
radio-frequency  amplification,  the  little  con- 
densers in  the  vacuum  tubes  themselves  cause 
much  mischief.  Small  condensers  are  formed 
by  the  grid  and  filament,  and  by  the  plate  and 
grid,  so  that  if  we  were  to  represent  these  little 
condensers  on  the  outside  of  a  vacuum  tube,  we 
would  have  a  picture  much  like  that  shown  in 
Fig.  4.  These  little  condensers  are  capable  of 
causing  oscillations  at  high  frequencies,  for  if  a 
pressure  exists  between  the  points  AB,  it 
will  not  only  send  a  current  through  the  little 
condensers  represented  by  the  plate  and  fila- 
ment, but  it  will  also  send  a  current  from  B 
to  C  through  the  little  condensers  repre- 
sented by  the  plate  and  grid,  and  by  the  grid 
and  filament,  respectively.  The  current  flow- 
ing through  the  condenser  between  E  and 
C  causes  the  proper  kind  of  voltage  to  be 
impressed  on  the  grid  of  a  tube  to  produce  an 
oscillating  current  in  the  plate  circuit,  if  the 
plate  circuit  contains  a  small  amount  of  in- 
ductance, as  shown.  Usually  the  grid  circuit 
also  is  tuned  by  an  inductance,  as  shown  by 


fig.  5 

A  recently  developed  set  of  the  Clapp-Eastham  Com- 
pany, having  one  stage  of  R.  F.,  detector,  and  two 
stages  of  A.  F.  amplification 


the  dotted  line.  This  aggravates  the  tendency 
for  the  tube  to  oscillate.  Therefore  one  may 
construct  a  radio-frequency  amplifier  with 
apparently  no  condensers,  and  yet  the  ampli- 
fier may  oscillate  and  give  no  results  whatever. 

Tuning  the  transformers  of  a  radio-frequency 
amplifier  has  the  effect  of  building  up  parallel 
circuits  of  capacitance  and  inductance  eager  to 
oscillate,  but  in  the  receiver  illustrated  in  Fig.  5, 
this  tendency  is  curbed  as  shown  in  Fig.  6. 

The  tuning  element  consists  of  a  series  an- 
tenna condenser  Ci  in  series  with  a  variometer 
V.  The  first  tube  is  used  as  a  radio-frequency 
amplifier,  and  it  is  coupled  to  the  detector  tube 
by  means  of  a  tuned  primary  radio-frequency 
transformer  which  is  prevented  from  oscillating 
by  means  of  the  control  condenser  C2.  This 
little  condenser  is  a  variable  of  about  .0002 
mfd.  capacity.  The  primary  of  the  radio- 
frequency  transformer  is  tuned  by  means  of 


FIG.  6 

Wiring  diagram  of  the  set  shown  in  Fig.  5.  The  oscillation  condenser  is  shown  as 
C2.  Note  that  the  B  battery  feeds  the  plate  of  the  R.  F.  tube  through  a  choke-coil 


2l8 


Radio  Broadcast 


^L4ot.4  5rVolfs  Fov  UV-ioiA 

C  Woke 


FIG.  7 

A  suggested  hook-up.  The  oscillation  control  condenser  is 
shown  as  C2.    Note  that  there  is  no  grid  condenser  or  grid  leak 


the  condenser  C3,  which  has  a  maximum  ca- 
pacity of  .001  mfd.  The  secondary  of  the 
radio-frequency  transformer  is  not  tuned  in 
any  way,  but  it  is  connected  directly  to  the 
grid  of  the  detector  tube,  as  shown.  The  con- 
trol condenser  in  the  plate  circuit  makes  it 
necessary  to  furnish  the  B  battery  voltage  to 
the  plate  through  the  radio-frequency  choke 
shown.  This  is  an  iron-cored  coil.  No  grid 
bias  is  used  in  this  set  and  there  is  no  stabilizing 
device  such  as  a  potentiometer.  It  is  interest- 
ing to  observe  that  the  detector  tube  contains 
no  grid  leak  or  grid  condenser.  The  designing 
engineer  for  this  company  has  found  that  the 
insertion  of  the  grid  leak  and  grid  condenser  in 
the  set  actually  hinders  its  operation. 

The  detector  tube  works  with  two  stages 
of  audio-frequency  amplification,  as  shown. 
These  are  of  the  usual  form.  The  dial  marked 
"•Osc.  Control"  (Fig.  5)  operates  the  condenser 
C2  (Fig.  6).  The  dial  marked  "antenna  in- 
ductance" operates  the  variometer  V,  and 
the  dial  marked  "radio-frequency  control" 
operates  the  condenser  C3.  These  dials  are 
unique  in  that  they  operate  at  all  times  with  a 
micrometer  adjustment;  that  is,  the  knob 
makes  several  revolutions  in  order  to  advance 
the  dial  through  its  full  scale.  The  condensers 
C2  and  C3  are  so  arranged  that  the  shaft  sup- 
porting the  moveable  plates,  and  running  to  the 
knob,  is  always  farthest  from  the  plate  side  of 
the  condenser;  that  is,  it  is  always  at  the  poten- 
tial nearest  that  of  the  filament.  In  this  way, 
body  capacity  effects  are  nearly  eliminated. 

A  variation  of  this  circuit  is  shown  in  Fig.  7. 
In  this  circuit  a  loop  is  used  in  conjunction  with 
a  small  tuning  condenser  Ci.    The  control 


condenser  is  shown  as  C2,  and  the  transformer 
tuning  condenser  as  C3.  The  radio-frequency 
transformer  may  be  made  up  of  cardboard 
tubes.  Bakelite  apparently  does  not  work 
as  well  under  ordinary  conditions.  The  two 
windings  may  be  placed  one  inside  the  other, 
as  shown  in  Fig.  8.  The  inner  winding  may 
be  used  as  the  primary  and  the  outer  winding 
as  the  secondary.  Both  coils  should  be  wound 
in  the  same  direction.  They  can  be  made  up 
with  ordinary  cotton  covered  or  enameled  wire 
of  from  Nos.  22  to  26.  The  primary  should 
have  comparatively  few  turns  compared  to  the 


\ 


FIG.  8 

A  cross-section  showing  the  ar- 
rangement of  the  coils  that  make 
up  the  primary  and  secondary  of 
the  R  F.  transformer.  The  two 
lower  leads  should  go  to  the  fila- 
ment and  B  battery  if  both  coils 
are  wound  in  the  same  direction 


secondary.  The  exact  number  can  be  deter- 
mined only  by  practice.  Roughly,  from  30  to 
40  turns  on  the  primary  and  from  75  to  100 
turns  on  the  secondary  will  probably  give  good 
results  if  the  ratio  of  the  diameter  of  the  prim- 
ary winding  to  that  of  the  secondary  is  about 
0.6.  The  radio-frequency  choke  may  consist 
of  an  old  primary  of  an  audio-frequency  ampli- 
fying transformer  or  any  iron-cored  coil  of  only 
a  few  layers  in  which  the  wire  is  not  too  fine. 

This  set  is  subject  to  almost  perfect  control 
by  means  of  the  series  plate  condenser  C2,  and 
with  it,  radio-frequency  at  short  wavelengths  is 
very  satisfactorily  accomplished. 


©  Clinedinst 


it  doesn't  take  long  to  get  it  hooked  up 


At  the  left  is  the  antenna  wire,  flung  out  of  the  window,  and  at  the  extreme  right,  the  ground  connection  on 
the  radiator.   The  plug  and  roll  of  wire  in  the  jaws  of  the  traveling  bag  are  an  alternative  aerial  appliance 


A  Portable  Set  for  Lonely  Hotel  Hours 

By  J.  T.  N. 


SOME  cynical  person  has  said  that  love 
of  home  is  chiefly  expressed  and  up- 
held by  the  homeless.  However  that 
'  may  be,  I  am  one  of  those  to  whom 
days  and  nights  at  home  are  a  luxury, 
and  days  and  nights  in  hotels  the  all  too  com- 
mon experience.  To  relieve  the  monotony 
there  have  been  always,  of  course,  various  ex- 
pedients, theatres,  movies,  books.  None,  how- 
ever, as  good  as  modern  radio.  At  least  I  find 
it  so.  I  am  often  too  tired  for  theatre  or 
movies,  even  if  there  is  an  attractive  offering. 
Also  my  mind  is  generally  too  full  of  the  day's 
work  to  favor  the  concentration  necessary  for 
profitable  reading.  Radio  makes  fewer  de- 
mands. No  matter  how  tired  or  preoccupied, 
you  can  listen.  Sweet  voices  sing  for  you, 
bands  play,  violins,  horns,  orchestras,  organs. 
Besides  there  are  frequently  broadcasts  of 
banquets  and  public  meetings.  Even  lectures 
and  speeches  do  not  tax  your  tired  energies 


when  you  know  they  can  be  turned  off  without 
disturbance  (or  discourtesy)  the  moment  they 
fail  to  hold  the  attention. 

The  advantages  of  radio  under  such  circum- 
stances are  obvious  enough  and  do  not  require 
elaboration.  My  purpose  here  is  to  tell  how 
1  manage  my  hotel  radio. 

My  method  is  simple.  After  years  of  ex- 
perience in  regulating  luggage — the  problem 
is  to  carry  all  one  needs  but  not  a  scrap  more — 
I  have  settled  down  to  a  suit  case  for  clothing, 
a  small  bag  for  toilet  articles,  pajamas,  books, 
etc.,  and  a  brief  case  for  documents.  The  brief 
case  frequently  travels  in  the  suit  case,  leaving 
only  two  articles  of  hand  luggage.  To  add 
radio  to  the  outfit  was  more  or  less  disconcert- 
ing to  one  of  settled  habits.  I  considered  hav- 
ing a  small  case  made  the  size  of  a  set,  with  the 
panel  just  inside  the  lid.  But  at  best  this 
involved  a  third  thing  to  carry  and  a  fourth 
when  the  brief  case  could  not  go  inside.    So  I 


220 


Radio  Broadcast 


rejected  the  idea  of  radio  in  a  separate  case.  I 
then  tried  packing  the  essentials  of  a  hook-up 
in  the  suit  case,  but  they  would  not  stay  put, 
and  the  result  was  a  mess,  involving  poor  radio, 
because  of  loosened  joints  and  fittings.  Fin- 
ally I  decided  to  get  a  larger  hand  bag  to 
substitute  for  the  small  one  carrying  toilet 
articles.  1  selected  one  with  a  fairly  wide  bot- 
tom and  ample  jaws.  On  a  board  or  base  a 
little  smaller  than  the  bottom  of  the  bag  1 
fastened  a  vario-coupler,  a  WD-i  i  tube  socket, 
a  small  rheostat,  a  combination 
grid-condenser  and  variable  grid 
leak,  and  four  small  binding  posts. 
These  I  screwed  down  securely 
wired  with  the  shortest  possible 
leads.  All  connections  were  well 
soldered.  To  the  most  convenient 
negative  A  battery  lead,  1  soldered 
short,  flexible  insulated  wire  ter- 
minating in  a  strong  battery  clip 
and  added  the  same  equipment  for 
the  positive  A  battery  lead  and  the 
positive  B  battery  lead.  (In  my  hook-up,  as 
will  be  seen,1  the  negative  B  battery  lead  con- 
nects with  the  negative  of  the  A  battery,  and 
consequently  this  is  not  a  part  of  the  fixtures 
on  the  board.)  1  also  soldered  a  short,  flexible 
wire  terminating  in  a  battery  clip  to  the  plate 
lead.  This  is  for  connecting  the  phones.  The 
outfit  thus  assembled  goes  to  the  bottom  of  the 
traveling  bag.  It  is  not  much  of  a  nuisance 
there  as  it  is  all  firmly  put  together.  The 
vario-coupler  is  a  commercial  unit  already 
equipped  with  dial,  switch  lever  and  points, 
fixed  on  a  little  panel  of  its  own.  Into  the  bag, 
in  convenient  corners,  I  also  tuck  a  roll  of  about 
fifty  feet  of  No.  18  stranded  flexible  insulated 
wire,  a  small  22^-volt  B  battery,  another  roll 
of  about  ten  feet  of  the  same  wire  with  battery 
clips  on  both  ends,  a  short  wire  similarly  pro- 
vided, a  pair  of  head  phones,  and  (in  case  it  is 
best  to  use  it  for  an  aerial  connection)a  radio 
plug  for  an  electric  light  socket,  with  about 
fifteen  feet  of  flexible  insulated  wire  attached, 
terminating  in  a  battery  clip.  I  carry  also  two 
WD-ii  tubes,  one  for  use  and  one  reserve 
against  a  possible  blow  out.  I  have  as  yet  no 
satisfactory  place  to  carry  the  tubes  and  they 
go  in  the  suit  case  cushioned  by  the  wearing 
apparel.  But  this  is  a  poor  makeshift.  Some 
sort  of  a  small  box,  padded  and  partitioned, 

\J.  T.  N.'s  hook-up  is  practically  the  same  as  the 
"Parker"  circuit.  [  his  is  shown  in  Fig.  i,  page  230,  of 
this  issue. 


would  be  the  thing,  but  I  have  never  happened 
on  one  so  far. 

There  is  nothing  peculiar  about  the  hook-up 
1  use  and  doubtless  it  could  be  improved 
somewhat  so  as  to  give  even  better  results. 
However,  I  would  reject  any  modification  which 
called  for  more  parts,  as  I  now  carry  quite 
enough  miscellany  in  that  bag.  (My  wife  oc- 
casionally inspects  it  with  expressions  of 
horror.) 

One  who  lives  much  in  hotels  learns  to 
adapt  himself  to  circumstances. 
To  have  radio  in  a  hotel  it  is  neces- 
sary to  call  upon  this  acquired  apti- 
tude. If  I  arrive  in  daylight  (and 
as  well  as  1  can  anyway)  I  inspect 
the  environment  before  register- 
ing. To  the  room  clerk  I  probably 
appear  rather  a  fussy  old  gentle- 
man, possibly  slipping  into  a  par- 
anoic state  with  fixed  ideas,  obsces- 
sions,  violent  likes  and  dislikes. 
Or  he  may  be  "on."  These  hotel 
clerks  know  a  lot  they  say  nothing  about. 

1  show  marked  preference  for  rooms  at  the 
top.  1  like- them  at  the  front,  or  at  the  rear, 
or  at  the  side,  as  the  case  may  be,  and  in  each 
case  I  am  very  definite  about  it.  (It  depends 
on  where  I  saw  the  telephone  and  telegraph 
wires,  the  trolley  lines  and  the  near  by  or  con- 
necting buildings).  1  am  apt  to  inquire  cas- 
ually about  the  construction  of  the  building. 
Old  hotels  are  best.  They  may  burn  you  up, 
but  in  the  meantime  the  radio  will  be  better. 
No  metal  construction,  of  course,  is  the  reason. 
Also  1  have  a  weather  eye  out  for  the  hotel 
detective.  I  do  not  intend  to  violate  any  rules, 
but  if  he  subsequently  thinks  my  wire  (if  I 
use  it)  is  intended  to  facilitate  an  escape  with- 
out paying  my  bill,  I  want  to  explain  before  he 
insults  me. 

Having  done  as  wek  as  I  can  in  the  location 
of  my  room,  1  inspect  its  interior.  A  glance 
takes  in  windows,  ledges,  available  ground. 
Radiators  are  usually  all  right  for  that;  maybe 
bathroom  connections  are  better,  but  I  seldom 
use  them  as  they  are  inconveniently  placed. 
Recently  in  an  overcrowded  hotel  where  1  had 
to  grab  anything  1  could  get,  the  room  had  no 
bath  and  no  radiator.  It  was  in  the  South.  I 
used  the  electric  light  wires  there  for  the  aerial 
and  was  puzzled  what  to  do  for  ground.  Fin- 
ally I  fastened  the  ground  wire  to  the  bed 
springs.  It  worked  beautifully.  I'd  heard  of 
bed  springs  for  aerials  but  not  for  ground.  (It 


A  Portable  Set  for  Lonely  Hotel  Hours 


22  I 


would  be  a  counter-poise 
doubtless.)  But  1  cannot 
claim  a  discovery,  for  the 
bed  spring  connection  fell 
off  and  the  reception  went  on 
without  any  change  what- 
ever. This  was  one  of  the 
old  hotels,  God  bless  'em, 
no  steel  construction  nor 
reinforced  concrete. 

Where  it  will  work,  and 
usually  it  will,  I  prefer  to 
drop  my  fifty-foot  wire  over 
the  window  sill.  I  select  a 
small  table,  move  it  over 
by  the  window,  take  out 
my  outfit,  throw  out  my 
wire,  and  clip  my  ground 
wire  to  the  radiator.  One 
telephone  lead  I  attach  to 
the  plate  circuit  by  letting 
the  clip  bite  it, and  theother 
telephone  lead  I  insert  di- 
rectly in  the  proper  tap  of 
the  B  battery.  My  short 
double  clipped  wire  con- 
nects B  minus  with  A  minus. 
I  forgot  to  tell  about  the 
filament  battery.  1  exclude 
it  from  my  outfit  because 
dry-cell  batteries  are  pur- 
chasable at  all  hours  and  at  low  cost  in  any  city. 

If  the  outside  wire  will  not  work  or  condi- 
tions will  not  permit  its  use,  1  try  the  electric 
light  connection.  I  have  never  had  any  real 
trouble.  Most  cities  have  local  broadcast 
stations  or  are  near  some  other  city  that  has. 
Sometimes  those  near  enough  for  my  single 
tube  and  more  or  less  haphazard  equipment 
operate  only  semi-occasionally  or  on  restricted 


©  Clinedinst 

A  WELCOME  RELAXATION,  AFTER  A  DAY  OF  WORK  AND  TRAVEL 
The  portable  apparatus  in  action  at  the  Shoreham  Hotel  in  Washington 


schedules  which  do  not  match  my  hours  of 
freedom,  but  I  seldom  fail  to  find  real  entertain- 
ment ready  at  hand.  Even  if  broadcasts  are 
lacking  there  are  near  by  amateurs  handling 
"traffic."  One  lulls  a  child  to  sleep  with 
monotony  and  repetition.  The  c-q-ing  of  the 
amateurs  has  a  similar  effect,  and  I  am  apt  to 
grow  drowsy.  Well,  that  was  what  1  wanted, 
wasn't  it? 


THE    IO-TUBE  SUPER-HETERODYNE  SET  WITH  WHICH  R.  R.  MAYO,  WHO  BUILT  IT,  HEARS 

EUROPE  REGULARLY 


AT  THE  FOOT  OF  THE   PRADO,  HAVANA 

Where  Cuban  beauties  and  beggars  share  the  moonlight  and  the  music,  while  the  light  on  famous 
old  Morro  Castle  winks  first  at  them  and  then  at  the  men  who  go  down  to  the  sea  in  ships 

A  Millionaire's  Cruise  on  an 
Operator's  Pay 

By  A.  HENRY 

Yachting  on  §40  a  month  is  possible  only  for  radio  men  (and  not  always  for  them!)  In  this  article 
— the  fifth  on  the  subject  of  "Operating  as  a  Career" — .Mr.  Henry  shows  us  further  lights  and  shadows  of 
one  of  the  most  fascinating  jobs  in  the  world. — The  Editor. 


T     FOLLOWING  my  dismissal  for  having 
i    missed  a  vessel  sailing  for  Nova 
I     '    Scotia,  you  may  imagine  my  surprise 
when  I  was  told  by  the  Superinten- 
dent that  my  case  had  been  recon- 
sidered and  that  he  was  pleased  to  offer  me  a 
fine  assignment.    After  dilating  upon  the  won- 
derful cruise  the  yacht  was  to  take,  it  was  no 


longer  necessary  for  him  to  "  sell "  the  job  to  me. 
As  advertising  men  say,  1  was  completely 
"sold."  Before  letting  him  know  this,  how- 
ever, I  went  through  the  business  of  showing 
indifference  and  mentioning  an  assignment 
promised  me  by  a  competing  company  in  the 
approved  manner.  Yes,  I  secured  the  raise. 
The  reason  for  my  being  selected  was  that  a 


A  Millionaire's  Cruise  on  an  Operator's  Pay 


223 


radio  outfit  had  to  be  installed  on  the  particular 
yacht  which  1  was  to  meet  at  Key  West,  and  1 
had  done  a  similar  job  on  the  IVakiva,  down  in 
Tampico.  The  equipment  had  been  on  its 
way  a  day  or  two  and  the}'  were  anxious  to  have 
me  follow  as  soon  as  possible.  A  steamer  was 
leaving  New  York  in  two  days  for  Key  West 
and  I  would  have  to  take  it  and  stay  at  a  hotel 
there  until  the  yacht  came  in.  Well,  you  can 
imagine  how  my  adventuresome  nature  re- 
sponded to  that !  One  does  not  care  to  aban- 
don the  winds  and  shows  of  New  York  in 
February  for  the  sunshine  and  flowers  of  the 
tropics,  but — 1  permitted  myself  to  be  per- 
suaded. 

Oh,  those  days  when  one  is  foot-loose  and 
fancy-free,  gloriously  young  and  satisfied  to 
be  off  in  a  balm}1,  spring  climate,  bound  for 
nothing  more  definite  but  nothing  less  exciting 
than  Travel  and  Adventure!  In  Key  West, 
the  world  smiled  and  I  smiled  back,  read}'  to 


lick  the  world  or  to  make  friends  with  all  of  it 
at  a  moment's  notice.  The  best  of  everything 
was  none  too  good  to  suit  me  and  the  worst 
was  none  too  bad  to  bother  me. 

During  the  five  days  at  Key  West,  following 
a  delightful  trip  on  one  of  the  Mallory  liners,  I 
lived  at  the  best  hotel  in  town  and  casually 
mentioned  to  one  or  two  of  the  gentlemen  with 
whom  1  became  acquainted  that  I  was  waiting 
for  my  yacht  and  that  we  were  going  to  take 
a  cruise  around  the  West  Indies;  whereupon  I 
found  that  even  Key  West  has  its  financial 
pirates.  One  man  of  about  middle  age  decided 
to  take  me  under  his  wing  and  show  me  around. 
He  dined  me  and  would  have  wined  me,  but  1 
did  not  indulge  at  the  time.  He  was  a  very 
smooth  article  and  kept  me  busy  making  eva- 
sive answers  to  his  pointed  questions  concerning 
my  finances,  family  and  the  like.  He  unfolded 
a  great  plan  for  making  a  fortune  in  a  jiffy  and 
let  me  know  from  time  to  time  that  he  had 


HINDU  SNAKE  CHARMERS  AND  FAKIRS  ABOUND  IN   PORT  OF  SPAIN 
The  weird  music  of  the  pipes  of  these  snake-charmers  in  Trinidad  is  of  a  variety  never  to  be  forgotten 


224  Radio 

confidence  in  me,  sought  my  judgment,  as  it 
were,  and  almost  succeeded  in  swelling  my 
head  beyond  the  limits  of  the  Panama  hat  1 
had  purchased.  My  wardrobe  was  complete 
enough  to  allow  me  to  accept  his  invitations 
to  a  dinner  or  a  dance  at  this  home  or  that  club. 
Key  West,  in  short  gave  me  a  reception  that 
was  not  half  bad.  1  was  alluded  to  as  a  friend 
of  the  Duke  of  Sutherland,  a  claim  1  had  never 
made,  but  didn't  deny  because  1  didn't  have 
the  heart  to  ruin  all  the  fun  these  folks  were 
having  entertaining  a  "friend  of  the  royal 
family." 

Many  of  them  begged  me  to  offer  the  Duke 
free  reign  in  their  homes  for  the  time  he  was 
to  be  in  Key  West;  several  tried  to  coax  me  to 
give  up  my  room  at  the  hotel  and  accept  their 
hospitality  during  my  stay.  In  saying  that  I 
knew  the  Duke  would  be  grateful  for  their 
kind  offers,  but  that  I  felt  sure  he  had  made 
arrangements  which  it  would  be  difficult  to 
change,  1  felt  that  the  truth  was  not  being 
transgressed ;  and  my  thanks  for  the  offer  to  me 
was  always  followed  by  a  refusal. 


roadcast 

Mr.  Van  Wicklen,  the  financial  gentleman, 
soon  took  it  upon  himself  to  ward  off  any  more 
such  offers  for  me,  saying  that  he  was  entitled 
to  first  consideration  and  that  I  had  repeatedly 
refused  him. 

Eventually  the  yacht  came  in,  and  by  drop- 
ping out  a  back  window  of  my  hotel  and  going 
down  the  fire  escape  1  managed  to  evade  the 
few  who  had  come  to  have  me  take  them 
aboard  the  yacht.  1  hired  a  launch  to  go  out 
and  introduce  myself  to  the  Captain.  As  we 
drew  up  to  the  port  gang-plank,  another  launch 
left  from  the  starboard  side,  and  from  a  vantage 
point  on  deck  1  saw  the  Duke  and  Duchess  of 
Sutherland  leave  for  the  shore  and  to  take  a 
train  back  to  the  North.  That  is  as  near  as  1 
ever  came  to  those  good  people.  To  my  great 
relief,  1  found  from  the  Captain  that  we  would 
tarry  but  a  few  hours  in  Key  West.  We  were 
to  wait  for  the  Count  and  Countess  Szechenyi, 
who  had  chartered  the  yacht  from  the  Duke. 
It  was  well  for  me  to  begin  immediately  to  in- 
stall the  radio  equipment. 

The  Captain  and  1  went  over  the  vessel  to- 


ON  THE  HIGHEST  OF  THE  THREE   LOCKS  AT  GATUN,  PANAMA 

Where  American  engineers  fought  every  form  of  tropical  disease  in  completing  one  of  the  largest  "jobs"  the  world  has 
ever  seen.    The  Chagres  River  may  be  seen  in  the  background.    Just  beyond  the  farthest  horizon  lies  the  Atlantic 


A  Millionaire's  Cruise  on  an  Operator's  Pay 


225 


gether  looking  for  a  suitable 
room  to  use  for  the  purpose. 
A  chat  with  the  Chief  Engi- 
neer, a  good-natured  Scot, 
revealed  that  the  ship's 
generator  was  rated  at  5K. 
W.  and  delivered  a  voltage 
of  35.  Great  Caesar's 
Ghost!  I  saw  my  trip  be- 
ing taken  away  from  me. 
Someone  had  bungled — for 
the  outfit  1  was  to  install 
was  designed  for  use  on  1 10 
volts  and  even  though  the 
voltage  had  been  correct, 
the  poor  little  dynamo  on 
the  yacht  could  never  have 
stood  the  load.  There  was 
only  one  thing  to  do  and 
that  was  to  get  the  ten-inch 
spark  coil  from  the  radio 
school  at  Key  West  and  use 
it  to  transmit.  The  local 
manager  refused  to  let  me 
have  it,  however,  and  it  was 
too  lateto  getanythingfrom 
New  York.  I  visited  several 
amateurs  in  an  attempt  to 
purchase  a  transmitting 
outfit,  but  could  find  none 
that  was  powerful  enough. 

All  that  day,  with  the 
assistance  of  the  local  man- 
ager, I  worked  erecting  an 
antenna  and  installing  a  re- 
ceiving set.  That  night  I  had 
somethingtotell  the  Captain 
confidentially.  He  agreed  to 
the  plan  1  unfolded,  put  two 
men  in  my  charge,  and  sent  us  ashore  in  the  ten- 
der. Once  ashore  we  made  for  the  radio  school, 
and  cracked  a  pane  of  glass  out  of  a  window, 
which  we  then  unlocked.  One  man  climbed 
through  and  it  was  then  easy  to  open  the 
automatic  lock  on  the  door  and  let  the  rest  of 
us  in.  With  the  aid  of  a  flashlight  we  found 
the  object  of  our  search,  the  treasured  coil, 
and  wrapped  it  up  in  burlap. 

Then  we  returned  to  the  yacht.  It  was  an 
easy  matter  to  put  a  sending  key  in  series  with 
the  electric  light  line  to  operate  the  coil  and 
there  we  were,  all  ready  to  go.  I  went  to  bed 
— and  the  next  morning,  when  1  woke  up,  we 
were  in  Havana  Harbor. 

During  the  day  1  was  too  busy  shopping  for 


WHEN  YOU  STAND  ON   MORRO  CASTLE 
On  one  of  those  brilliant,  peaceful,  tropical  days;  with  the  Cuban  flag  snapping  in 
the  breeze  above  you  and  small  craft  cutting  the  blue  Carribbean  far  below — it 
comes  over  you  with  a  thrill  that  you  wouldn't  be  anywhere  else  and  you  wouldn't 
change  jobs  with  any  man 


white  uniforms  to  reflect  much  upon  my  recent 
activities,  but  in  the  evening  when  I  had  a 
chance  to  review  the  past  week,  1  wondered 
what  had  happened  in  the  radio  school  when 
they  found  that  the  place  had  been  burglarized. 
1  chuckled  as  1  wondered  what  Mr.  Van  Wick- 
len  said  upon  finding  that  the  Western  Union 
messenger  had  paid  my  bill  at  the  hotel  and 
ordered  my  luggage  sent  aboard  the  yacht. 

Havana  Harbor  and  Havana!  I  thought  of 
all  the  stories  I  had  read  and  heard  of  that 
wonderful  city.  Many  a  time  and  oft  had  my 
algebra  teacher  held  me  up  to  ridicule  before 
the  class  for  reading  a  book  of  travel  held 
between  the  bottom  of  my  desk  and  my  knees, 
instead  of  paying  attention  to  a  dissertation  on 


226 


Radio  Broadcast 


the  value  of  X.  I'm  afraid  X  never  appeared 
very  valuable  to  me.  Some  of  the  tales  I  had 
read  must  have  been  written  many  years  before, 
because  I  found  it  difficult,  when  traveling 
about  the  city,  to  locate  any  of  the  haunts  1 
had  read  about. 

The  Chief  Engineer's  son  was  a  chap  of  about 
my  own  age,  and  we  went  out  to  see  Havana 
together.  A  military  band  played  in  the 
Plaza  that  night  and  a  cosmopolitan  gathering 
walked  and  talked  and  listened  with  languorous 
enjoyment. 

We  walked  down  the  Prado,  where  Cuban 
beauties  strolled  in  grandeur,  for  the 
edification  of  us  passers-by,  and  the 
children  amused  themselves  with 
roller  skates  and  velocipedes.  We 
dropped  in  at  a  cabaret  called  "The 
Black  Cat"  and  saw,  among  others, 
a  great  many  Americans  of  the  race- 
horse-following variety.  Then  we 
sauntered  on  to  the  bandstand  where 
a  great  crowd  sat  in  the  moonlight  and  listened 
to  the  music.  Flivvers  and  limousines  whizzed 
by;  voices  sang  or  called  out  gaily;  and  small 
craft  made  their  way  in  and  out  of  the  harbor. 
No  worry,  no  hurry — nothing  to  do  but  take 
in  everything  with  grateful  eyes  and  ears — and 
be  glad  to  be  alive. 

On  our  way  back  we  stopped  in  a  soft  drink 
establishment  and  watched  a  native  skin  a 
pineapple,  cut  it  in  chunks,  put  it  in  a  thing 
that  looked  like  a  chemist's  mortar,  beat  it  to 
a  pulp  and  strain  the  juice  off  into  glasses  for 
us.  It  was  delicious.  To  attempt  to  tell  you 
of  the  wonderful  sights  of  Havana,  from  the 
Country  Club  to  the  race  track,  from  Miramar 
to  the  Municipal  Wharves,  would  be  foolhardy. 
I  think  you'll  have  to  go  there.    .    .  . 

Following  our  two  days'  stay  at  Havana,  we 
went  around  the  north  coast  of  Cuba  to  a  small 
town  called  Nuevitas.  We  were  told  that  tar- 
pon fishing  in  Nuevitas  Bay  was  good.  It 
certainly  was.  Even  as  a  schoolboy,  I  could 
never  wax  enthusiastic  over  fishing,  for  there 
never  seemed  to  be  enough  action  in  it,  but 
there  is  fishing  and  FISHING.  In  Cuba  I  was 
given  a  taste  of  the  latter. 

At  night  we  hung  a  cluster  of  lights  over  the 
rail  near  the  gangway,  then  threw  bits  of  meat 
and  bread  into  the  water.  In  a  few  seconds 
what  appeared  to  be  dozens  of  large  silver-hued 
fish  were  scrambling  for  the  food.  When  they 
gathered  in  numbers  this  way,  one  of  the  quar- 
termasters would  hurl  a  harpoon  at  them. 


Every  hurl  usually  meant  a  fish.  But  catching 
fish  is  one  sport,  and  catching  tarpon  is  another. 
With  a  harpoon  right  through  one  of  them  he 
would  swim  first  in  one  direction  then  dart  in 
another,  then  shoot  six  or  eight  feet  in  the  air, 
going  through  all  sorts  of  contortions  to  break 
away.  Some  of  them  would  bite  fiercely  at 
the  bronze  cable  that  held  the  harpoon  to  the 
line.  A  large  tarpon  would  require  two  or 
three  men  to  pull  him  in  unless  he  was  "  played  " 
and  playing  such  fish  with  a  line  and  rod  is  a 
very,  very  different  game  from  snagging  sun- 
fish  with  a  worm  and  a  bent  pin. 

After  a  few  days'  sport  at  Nuevitas, 
we  dropped  in  at  Jacmel,  Haiti.  We 
were  going  to  go  to  Port  au  Prince  but 
an  insurrection  there  caused  a  change 
in  our  plans.  Anyway,  it  could  hardly 
have  been  more  interesting  than  Jac- 
mel. Voodooism  is  still  an  active  cult 
among  the  Negroes  of  Haiti,  and  a 
part  of  the  ceremony  connected  with 
this  particular  form  of  worship  includes  offering 
an  occasional  human  sacrifice.  One  of  these 
celebrations,  if  you  will,  was  well  under  way 
when  we  arrived. 

Those  engaged  in  the  festivities  were  be- 
decked in  all  manner  of  weird  costumes.  Non- 
descript and  informal  paraders  followed  a  num- 
ber of  seemingly  self-appointed  leaders  in  a 
riotous  march  through  the  rows  of  huts  that 
made  up  the  town.  Each  of  the  leaders  carried 
a  large  staff,  dangling  from  the  top  of  which 
was  some  part  of  the  sacrificed  unfortunate's 
body. 

Jacmel  is  on  the  slope  of  a  hill  and  is  one  of 
the  dirtiest  places  it  has  ever  been  my  privilege 
to  see.  Open  sewers  ran  through  the  main 
streets  and — but  what's  the  use!  I'm  afraid 
Jacmel  cannot  be  remembered  as  being  partic- 
ularly fragrant. 

Our  next  stop  was  made  at  Kingston, 
Jamaica,  where  one  could  not  help  being  im- 
pressed with  the  tropical  beauty  that  makes 
so  fitting  a  frame  for  the  spotless  city  that  a 
few  years  before  had  been  wrecked  by  an 
earthquake.  Our  tender  slipped  alongside  a 
little  wharf  at  the  foot  of  the  public  market  and 
we  were  immediately  surrounded  by  a  crowd 
of  Negroes  who  beamed  at  us  as  they  offered 
mangoes  and  alligator  pears  (that  is  not  the 
correct  name,  but  it  is  the  one  most  used) 
and  tobacco  made  up  into  rope,  and  strings  of 
bright  colored  beads  made  from  berries  and 
beans.    These  Negroes,  who  spoke  with  a  pro- 


A  Millionaire's  Cruise  on  an  Operator's  Pay 


227 


THE  ALLIANCA — FIRST  LINER  TO  GO  THROUGH  THE  GATUN  LOCKS 
"Although  you  may  not  recognize  me,"  writes  Mr.  Henry,  "I  am  on  the  boat  deck  in  the  picture — sailed  a  few  months 
later  on  this  cruise  as  operator.    We  have  let  go  the  lines  from  the  'electric  mules'  and  are  headed  for  Gatun  Lake" 


nounced  English  accent,  were  politeness  per- 
sonified, despite  their  attempts  to  sell  us  more 
than  we  could  carry. 

But  in  telling  you  of  this  trip  I  have  failed 
to  mention  the  fact  that  I  did  a  certain  amount 
of  radio  work.  Among  other  things — very  few 
others — I  copied  press  from  the  German  station 
at  Sayville,  Long  Island  (SL)  each  night  and 
banged  it  out  with  a  few  carbon  copies  on  a 
Corona  borrowed  from  the  Countess.  The 
time  signals  from  NAA,  Arlington,  were  a 
revelation  to  the  Captain,  and  he  was  delighted 
to  have  the  weather  reports  which  came  in 
twice  a  day.  In  mentioning  the  radio  outfit, 
I  cannot  refrain  from  telling  you  of  a  record 
made  with  that  purloined  ten-inch  spark  coil 
To  my  knowledge,  it  has  never  been  beaten  and 
is  seldom  approached.  While  we  were  in 
Santo  Domingo  City,  the  Count  wanted  to 
arrange  for  a  railroad  car  for  some  friend, 
and  requested  a  message  sent  to  that  effect. 
The  radio  station  at  Santo  Domingo  (SD)  was 
out  of  commission  at  the  time,  owing,  I  was 
informed,  to  an  enterprising  operator's  having 
departed  with  part  of  the  equipment — and  after 
attempting  to  reach  Guanica,  Porto  Rico, 
without  success,  I  was  surprised  to  hear  P, 


the  old  spark  station  in  the  Isle  of  Pines,  south 
of  Cuba,  tell  me  to  go  ahead  with  my  message. 
I  did,  and  he  sent  me  an  OK.  In  a  few  minutes 
I  heard  him  send  it  on  to  M  (Morro  Castle, 
Havana),  but  I  could  not  hear  M.  The  air-line 
distance  to  the  Isle  of  Pines  was  480  miles — 
a  long  way  to  bat  with  a  ten-inch  coil  and  a 
crystal  receiver,  in  daylight.  That  night  the 
reply  to  the  Count's  message  was  among  those 
sent  broadcast  by  SL. 

Upon  leaving  Jamaica,  we  went  north  again, 
as  far  as  Santo  Domingo  City,  and  arrived  just 
in  time  to  witness  the  annual  ceremony  at  which 
the  natives  carry  the  bones  of  Columbus 
through  the  streets. 

In  mentioning  the  next  few  places  we 
stopped,  it  may  be  well  for  me  to  quote  a  letter 
from  Rosea,  Dominica  sent  while  making  the 
cruise: 

You  must  be  having  a  wonderful  time  with  all 
the  trolleys  and  traffic  tied  up  by  snow.  Last  night 
I  received  a  report  from  Sayville,  saying  that  you 
have  had  the  worst  blizzard  since  1888.  Here  the 
summer  attire  we  are  now  wearing  is  frequently  too 
heavy  for  comfort. 

We  stopped  in  at  Basseterre,  St.  Kitts,  long  enough 
to  have  a  look  around  and  mail  a  few  post  cards. 


228 


Radio  Broadcast 


BALBOA  S  PACIFIC,   FROM  THE  SUMMIT  OF  AN  CON  HILL  ABOVE  PANAMA  CITY 
Just  to  the  right  is  the  Pacific  entrance  to  the  Canal.    Mr.  Henry  says  he  will  never  for- 
get this  scene;  and  the  incident  of  the  flag-pole,  which  he  describes,  tells  one  reason  why 


Then  followed  a  glorious  run  through  the  Virgin 
Isles.  These  islands  are  composed  of  lava  and 
brimstone  thrown  up  by  some  volcano,  now  extinct 
or  sleeping. 

Every  time  we  set  foot  ashore,  we  are  set  upon 
by  a  band  of  blacks  who  hover  around,  begging 
pennies.  I  don't  wear  a  uniform  or  carry  a  sign,  but 
someone  in  the  band  is  bound  to  single  me  out  and 
tell  me  they  have  some  nice  things  to  show  the 
"wireless."  The  "nice  things"  they  have  to  sell 
usually  amount  to  little  more  than  a  few  woe-begone 
post  cards  or  a  poor-grade  Panama  hat. 

From  here  we  go  to  Martinique,  St.  Lucia,  St. 
Vincent,  Grenada,  Trinidad,  La  Guayra,  and  Cura- 
sao. With  such  an  itinerary  before  us  I  can't  help 
feeling  like  a  millionaire — this  is  the  life. 

And  it  was  the  life! 

Each  one  of  the  islands  and  towns  had  an 
individuality,  but  the  one  that  made  the  great- 


est impression  upon  me  was  St.  Pierre  on  the 
island  of  Martinique,  for  here  twelve  years 
before,  fire  and  brimstone  from  an  active  vol- 
cano had  wrought  havoc  with  the  little  town. 
Many  of  the  battered  walls  were  still  standing. 
Great  crevasses  could  be  seen  in  the  hillsides, 
caused  by  the  burning  lava  as  it  flowed  toward 
the  sea.  The  natives  tell  of  three  vessels,  lying 
at  anchor  in  the  harbor  when  the  eruption  took 
place,  which  were  demolished,  and  how  at  cer- 
tain times  they  appear  again  in  phantom  form, 
lying  at  anchor  in  the  harbor. 

One  incident,  which  you  will  agree  is  enough 
to  stick  in  a  fellow's  memory,  occurred  in  Fort 
de  France.  Several  young  natives  had  paddled 
their  little  boats  out  to  where  we  were  at  an- 
chor, and  we  had  been  having  great  sport 
watching  them  dive  for  coins  thrown  into  the 


A  Millionaire's  Cruise  on  an  Operator's  Pay 


229 


water.  The  water  was  so  inviting  that  1  de- 
cided to  have  a  little  swim  myself,  and  inasmuch 
as  my  clothing  was  light,  I  dove  right  off  the 
gangway  and  was  soon  having  as  much  fun  as 
the  little  coal-black  roses.  My  attention  was 
attracted  by  several  people  on  board  rushing 
to  the  rail,  shouting  and  gesticulating  wildly. 
I  thought  something  had  happened  on  the  ship 
and  that  I  was  wanted  in  a  hurry,  so  I  made  for 
the  gangplank.  As  I  approached  it,  two  sailors 
who  had  rushed  down,  grabbed  me  by  the  arms 
and  whisked  me  out  of  the  water.  I  looked 
back  into  the  water  and  saw  several  huge  shark- 
fins  in  silent  retreat. 

Following  a  short  stay  at  La  Guayra  and 
Curacao,  we  went  to  Colon,  Panama.  There 
we  had  a  mighty  fine  look  at  the  greatest  engi- 
neering undertaking  in  the  world.  Little  did 
I  imagine  at  the  time  that  a  few  months  later 
it  would  be  my  good  fortune  to  be  on  the  first 
ocean  liner  to  pass  through  the  Gatun  Locks. 

In  Colon,  I  met  a  friend  who  was  Radio 
Officer  on  a  Panama  Liner  and  he  arranged  for 
a  railroad  pass  to  Panama  City  for  me.  Among 
a  million  and  one  other  things  1  saw  the  locks 


at  Mira  Flores  and  Pedro  Miguel  and  climbed 
up  Ancon  Hill,  which  is  just  above  Panama 
City.  Not  satisfied  with  the  wonderful  view 
of  the  city  and  the  canal  and  the  Pacific  that 
this  vantage  point  offered,  1  climbed  to  the 
top  of  a  topographical  tower  and  then  shinned 
up  the  mast  to  the  cross  tree,  used  to  hold  the 
red  cloth  marker.  When  I  had  almost  reached 
the  top,  the  mast  snapped,  and  I  fell  to  the 
upper  platform,  suffering  no  further  injury 
than  a  huge  rip  in  the  seat  of  my  trousers, 
which  had  caught  on  the  projecting  part  of  the 
mast.  A  pair  of  khaki  trousers  from  a  local 
shop  relieved  the  only  embarrassment  caused 
by  the  fall. 

From  Panama  we  made  another  stop  at 
Kingston,  to  take  on  coal,  and  then  returned  to 
Key  West  by  way  of  the  south  coast  of  Cuba. 
Here,  1  dismantled  the  radio  equipment,  re- 
turned the  coil  1  had  stolen  from  the  school 
there  and  said  good-bye  to  the  good  yacht 
Catania. 

The  only  people  in  the  world  who  can  take  a 
trip  of  this  sort  are  millionaires  and  radio  men. 
The  radio  game  is  surely  worth  the  candle. 


OFF  FOR  A  TRIP  AROUND  THE  WORLD 


Peter  Taylor,  radio  man  (with  cap);  his  sister,  Mildred  Taylor,  writer  (in  the  car);  and  Blanding  Sloan,  artist  (not  shown) 
left  City  Hall,  New  York,  on  April  26th  for  a  trip  to  the  Orient  and  around  the  world.  The  radio  set,  an  important  part 
of  the  travelers'  equipment,  was  stowed  on  the  port  side  of  their  car.  Among  other  things,  the  trip  will  be  productive  of 
articles  and  photographs  concerning  radio  in  other  lands,  which  will  be  prepared  especially  for  Radio  Broadcast. 
Arthur  H.  Lynch,  (at  Mr.  Taylor's  right),  Editor  of  Radio  Broadcast,  joined  in  seeing  the  party  off 


A  Home-Made  Amplifier  for  Any 

Receiver 

By  ZEH  BOUCK 

Many  owners  of  single-tube  sets  who  have  considered  adding  audio-frequency  amplifiers  are  prevented 
from  doing  so  either  because  of  the  expense  or  because  they  have  the  idea  that  a  two-stage  amplifier  is  a 
difficult  piece  of  apparatus  to  construct  or  handle.  An  inquiry  into  the  prices  of  the  necessary  tubes,  sock- 
ets, transformers,  etc.,  will  allow  you  to  settle  the  cost  question  for  yourself.  This  article  will  show  that  the 
second  obstacle — difficulty  of  construction  or  operation — is  somewhat  of  a  myth.  It  will  show  you  not 
only  how  to  make  a  two-stage  amplifier  from  standard  parts,  obtainable  from  any  good  radio  dealer,  but  also 
how  to  use  it  to  best  advantage  with  the  receiver  you  already  have.  And  even  if  you  are  using  or  expect  to 
use,  a  bought  amplifier,  Mr.  Bouck's  tips  on  the  proper  connections  may  put  the  breath  of  life  into  a  "dead" 
set,  or  improve  a  set  that  is  not  quite  "hitting  on  all  cylinders." — The  Editor. 


CONSIDERABLE  uncertainty  ex- 
ists in  the  minds  of  many  enthu- 
siasts as  to  the  operation  and 
application  of  audio-frequency 
amplifiers,  probably  the  most 
simple  and  most  standardized  of  audion  cir- 
cuits. The  impression  of  complication  is  due, 
for  the  greater  part,  to  the  general  miscon- 
ception that  different  tuning  circuits  require 
different  systems  of  amplification.  This  idea 
is  altogether  at  variance  with  fact,  for  the  A.F. 
amplifier  is  a  unit  that  can  be  added  to  any 
receiver  without  varying  the  connections 
to  the  amplifier.  However,  it  is  sometimes 
necessary,  for  greater  simplicity  and  B  battery 
economy,  to  alter  slightly  the  plate  circuit 


FIG.  I 

Experimenters  endeavoring  to  add  amplification  to  this 
circuit  have  run  up  against  many  difficulties,  including 
the  burning  out  of  tubes  and  the  shorting  of  high-voltage 
batteries.  In  this  case,  the  voltage  taps  are  taken  on 
the  wrong  side  of  the  B  battery.  Ci  is  of  .001  mfd. 
capacity,  C2  is  a  telephone  condenser  of  .0025  mfd.  and 
C3  is  a  grid  condenser  of  .0005  mfd. 


connections  of  the  receiver  proper.  The  ma- 
jority of  unsuccessful  attempts  at  adding 
audio-frequency  amplification,  particularly  to 
the  "Parker"  circuit  (Fig.  i)  and  the  Peterson 
"Automatic  Regenerative"  circuit  (Fig. 2),  have 
been  due  to  the  failure  to  re-arrange  the  posi- 
tions of  the  B  battery  and  phones. 

Changing  the  sequence,  or  varying  the  rela- 
tive positions  of  different  pieces  of  apparatus 
in  a  circuit,  affects  neither  the  circuit  nor  its 
operation,  while  it  may  greatly  facilitate  the 
addition  of  auxiliary  equipment.  (The  fan 
should  familiarize  himself  with  the  fundamen- 
tals of  important  circuits  in  order  that  he  may 
recognize  them  camouflaged  by  the  eccentrici- 
ties of  individual  experimenters.)  For  ex- 
ample, in  a  single  bell  ringing  circuit,  the  elec- 
trical position  of  the  push-button  is  immaterial 
in  so  far  as  the  operation  of  the  bell  is  concerned. 
However,  if  more  bells  than  one  are  to  be 
operated  from  the  solitary  push-button,  it 
must  then  be  placed  in  a  lead  common  to  all 
bells.  In  a  single-bulb  receiving  circuit,  the 
position  of  the  B  battery  is  unimportant  as 
long  as  it  places  the  required  positive  charge  on 
the  plate  and  the  current  passes  through  the 
telephone  receivers.  But  when  amplification 
is  added,  the  position  of  the  battery  must  be 
such  that  it  may  impress  its  potential  across 
all  the  tubes. 

EXAMINE  THE  B  BATTERY  CONNECTIONS 

IN  ARRANGING  a  receiver  for  the  addition 
I  of  audio-frequency  amplification,  it  should 
be  first  determined  if  there  are  any  instru- 
ments between  the  A  and  B  batteries,  such  as 
telephone  receivers,   variometers  and  plate 


A  Home-Made  Amplifier  for  Any  Receiver 


231 


FIG.  2 
Another  sticker  to  am- 
plify.   The  phones  are 
on  the  wrong  side  of  the 
B  battery.    (See  Fig.  4) 


t 


WW 


tuning  devices.  Figs.  1  and  2  show  circuits  with 
this  (undesirable)  arrangement.  Such  inter- 
battery  apparatus  should  be  moved  to  the 
plate  side  of  the  B  battery,  and  the  latter 
connected  directly  to  the  filament  lighting 
source.  Fig.  3  and  4  show  practically  the 
same  circuits  with  the  changes  made,  and 
to  which  amplification  may  be  added  without 
more  ado. 

The  standard  amplifying  circuit  is  shown 
in  Fig.  5.  The  required  instruments  are 
plainly  indicated  on  the  diagram,  and  are 
carried  by  any  well  stocked  radio  supply  house. 
In  securing  the  apparatus  the  experimenter 
should  be  satisfied  with  only  the  best  obtain- 
able. This  applies,  not  merely  to  tubes  and 
transformers,   but  equally  well  to  sockets, 


rheostats,  and  jacks.  The  unsatisfactory  oper- 
ation of  home-made  amplifying  apparatus  is 
due,  in  the  majority  of  cases,  to  defects  in 
mediocre  instruments  which  give  rise  to  dis- 
torted and  noisy  amplification.  The  leads  on 
the  transformers  should  be  examined,  in  order 
to  determine  which  wires  run  from  the  outside 
of  the  primary  and  secondary  windings  (ends 
farthest  from  the  core).  These  leads  should 
connect,  one  to  the  plate  of  the  preceding  tube 
(the  outside  lead  of  the  primary)  and  one  to 
the  grid  of  the  succeeding  tube  (the  out- 
side lead  of  the  secondary).  This  correct 
disposition  of  the  transformer  leads  is  a  factor 
which  contributes  greatly  to  the  success  of  the 
amplifier.  Jacks  one  and  two  are  double- 
circuit  jacks,  while  the  third  may  be  of  the 


fig.  3 

This  is  Fig.  1  with  slight  alterations  and  the  amplifier  connected  in  the  proper  way 


232 


Radio  Broadcast 


fig.  4 

This  is  Fig  2  corrected  and  ready  for  amplification 

open-circuit  type.  The  condenser  across  the 
input  is  a  small  fixed  capacity  of  approximately 
.001  5  mfd.,  commonly  called  a  telephone  shunt 
condenser.  It  is  possible  that  such  a  con- 
denser already  exists  in  the  enthusiast's  un- 
amplified  receiver,  and  if  such  is  the  case,  an 
extra  capacity  is  not  required. 

The  connections  of  the  various  instruments 
should  be  made  with  hard-drawn  wire  of  a 
size  not  smaller  than  number  eighteen.  The 
wiring  should  be  well  spaced,  and  needless  to 
say,  every  joint  soldered.  Particular  care 
should  be  taken  in  making  clean  and  firm  con- 
nections to  the  jacks.  Use  the  least  amount 
of  flux  necessary  to  effect  a  perfect  joint,  and 
any  superfluous  acid  or  paste  should  be  re- 
moved by  wiping  with  a  rag  dipped  in  wood 
alcohol.  Bungled  soldering  on  the  jacks  is 
the  cause  of  seventy-five  per  cent,  of  "tube 
noises"  in  audio-frequency 
amplifiers. 

The  additional  B  battery 
should  be  of  at  least  40 
volts,  which,  when  con- 
nected as  indicated  to  the 
detector  plate  supply,  will 
place  a  potential  of  some 
60  volts  on  the  amplifying 
tubes.  This  is  generally  a 
minimum  voltage  for  satis- 
factory amplification.  Still 
greater  intensification  will 
be  had  on  voltages  in  the 
neighborhood  of  one  hun- 
dred, though  distortion  will 
be  more  marked.  The  use 
of  a  power  tube  in  the  final 
stage  of  amplification  will 


often  improve  the  quality  of  amplified  speech. 
Voltages  in  excess  of  100  seldom  give  satis- 
factory results  on  ordinary  amplifiers,  and 
should  in  general  be  avoided  as  it  sometimes 
happens  that  this  voltage  results  in  burning 
out  the  transformer  secondary. 

The  construction  of  the  amplifier,  while  n 
a  difficult  matter,  should  be  undertaken  by  the 
fan  only  after  he  has  had  the  experience  of 
building  an  efficient  single-bulb  set.  The  me- 
chanical details  of  a  popular  form  of  construc- 
tion are  shown  in  Figs.  6  and  7,  and  the  di- 
mensions are  approximately  indicated.  The 
panel  should  be  of  bakelite,  hard  rubber  or  a 
similar  insulating  material  at  least  one  quarter 
of  an  inch  thick.  The  instrument  shelf  may 
be  of  the  same  material  or  of  unpainted  wood. 
There  are  several  ways  in  which  this  last  may 
be  mounted,  and  many  amateurs  make  the 
jacks  do  a  double  duty  by  utilizing  them  as 
supporting  brackets  for  the  shelf.  This,  how- 
ever, subjects  the  panel  to  considerable  strain, 
and  the  writer  recommends  the  use  of  wooden 
blocks  or  small  brass  brackets.  These  are 
screwed  to  the  panel  at  such  a  height  that  the 
tops  will  be  on  a  level  with  the  tops  of  the 
jacks  (Fig.  6),  which  will  lend  an  additional 
support  to  the  shelf  without  endangering  the 
panel.  The  wooden  blocks  should  be  as  large 
as  possible  without  being  cumbersome  and 
interfering  with  mounting  and  wiring.  The 
small  insert  in  Fig.  7  indicates  the  preferred 
method  of  mounting  the  sockets,  transformers, 
etc.  The  cores  of  the  transformers  are  placed 
at  right  angles  to  each  other  in  order  to  reduce 
the  possibility  of  inductive  feed-back  and 


TO+OF 
DET.'B-BAT. 


FIG.  5 

The  standard  amplifying  circuit  for  connection  to  any  receiver 


A  Home-Made  Amplifier  for  Any  Receiver 


233 


howling.  Binding-posts  on  the  shelf  are  also 
provided  for  connecting  the  batteries  behind 
the  cabinet. 

PREPARING  THE  PANEL  FOR  DRILLING 

THE  panel  may  be  drilled  at  an  electrical 
or  machine  shop  at  a  very  small  cost,  and 
many  supply  houses  perform  this  service  gratis 
for  customers  who  purchase  from  them  the 
apparatus  required  in  the  construction  of  the 
amplifier.  In  preparing  the  panel  for  pro- 
fessional drilling,  the  positions  of  the  holes 
should  be  carefully  laid  out  and  center-punched. 
The  panel  should  be  accompanied  by  a  rough 
sketch  on  paper  showing  the  locations  and 
sizes  of  the  holes.  Excepting  for  the  peep- 
holes, and  those  passing  the  rheostat  shafts 
and  jack  shanks,  the  holes  may  be  drilled  for 
the  passage  of  a  No.  8  screw.  This  will  permit 
the  use  of  comfortably  large  wood  screws,  and 
in  the  case  of  smaller  machine  screws,  will 
allow  for  slight  inaccuracies  in  drilling. 

If  the  experimenter  possesses  a  small  hand- 
drill,  the  panel  work  may  be  done  on  his  own 
bench.    However,  he  will  probably  find  that 


fig.  6 

Indicating  the  approximate  dimensions 
of  the  panel  and  the  positions  of  holes 


FIG.  7 

Showing  the  preferred  method  of  mounting  the  shelf 
and  instruments  behind  the  panel.    Note  the  trans- 
formers at  right  angles  to  each  other 

the  large  peep-holes  present  somewhat  of  a 
problem.  This  is  most  easily  overcome  by 
making  a  group  of  small  holes  arranged  sym- 
metrically. 

Before  building  the  amplifier,  the  fan  will 
do  well  to  examine  some  commercial  amplifier 
of  reliable  make. 

The  amplifier  described  is  connected  to  the 
receiver  by  effecting  the  indicated  battery  con- 
nections (Fig.  5)  and  by  connecting  the  input 
wires  in  place  of  the  telephone  receivers. 
These  last  should  be  wired  to  a  standard  plug 
fitting  the  jacks. 

The  experimenter  need  not  build  the  two 
stages  at  one  time.  Even  a  single  step  adds 
greatly  to  the  enjoyment  one  may  derive  from 
a  receiving  set,  and  it  often  makes  possible 
the  use  of  a  loud  speaker  on  near-by  stations. 
In  adding  a  single  stage  of  amplification,  the 
second  transformer  and  tube  are  eliminated 
from  Fig.  5,  and  the  remaining  connections 
made  as  indicated.  A  one-step  amplifier  will 
give  an  average  signal  intensification  of  five 
to  twenty  times,  while  two  stages  will  multiply 
the  sound  of  the  detector  output  from  one 
hundred  to  four  hundred  times. 


How  Far  Have 
You  Heard? 

On  Any  Number  of  Tubes 

2500-mile  reception  has  been 
achieved  by  two  contestants, 
with  home-made  apparatus 


0® 


Reports  from  all  over  the  country  indicate  that  our  second  "How  Far  Have  You  Heard?"  Contest 
has  created  a  great  deal  of  enthusiasm.1  Inasmuch  as  this  issue  goes  to  press  before  May  31st  (the  date 
the  contest  ends),  it  is  impossible  to  declare  the  winners  or  to  print  some  of  the  best  reports;  but  the 
winners  will  be  announced  next  month,  and  their  articles,  as  well  as  others  of  particular  interest  submitted 
in  the  "How  Far?"  Contest,  will  appear  in  the  next  and  subsequent  issues. — The  Editor. 

A  5-Tube  Receiver  that  "Delivers  the  Goods" 

By  E.  D.  HARRINGTON 


B 


ECOMING  dissatisfied  with  a  crys- 
tal receiving  set,  as  most  broadcast 
listeners  do,  1  became  more  and 
more  determined  to  build  for  myself 
an  audion  set  that  would  satisfy  the 
most  exacting  person.  1  began  by  reading 
available  data  and  articles  published  on  va- 
cuum tubes,  condensers,  transformers,  aerials, 
etc.,  and  when  more  or  less  assured  that  I  under- 
stood the  underlying  principles  of  radio  recep- 
tion, 1  began  building  my  set.  My  observa- 
tions and  studies  had  soon  assured  me  that 
although  not  many  were  as  yet  using  radio 
frequency,  it  was  by  far  the  most  desirable,  in 
that  the  results  obtained2  seemed  easily  worth 
the  increased  time,  effort  and  amount  of  money. 

As  was  to  be  expected,  I  had  much  trouble 
at  first  and  lost  many  good  hours  of  sleep  puz- 
zling over  different  wiring  diagrams,  and  build- 
ing various  sets  with  all  sorts  of  hook-ups.  I  he 
result  was  that  six  months  after  1  started,  1 
completed  the  set  I  am  about  to  describe.  In 


'This  Long- Distance  Receiving  Contest,  held  to  de- 
termine who  has  done  the  best  work  with  any  number  of 
tubes  and  any  kind  of  receiver,  was  explained  in  full,  with 
a  list  of  prizes  for  winners,  in  the  March,  April,  May,  and 
June  issues  of  Radio  Broadcast. 

2 With  the  set  described,  Mr.  Harrington  has  heard  16 
stations  more  than  1000  miles  from  his  home  (Berkeley, 
California)  including  6  more  than  2000  miles  away.  His 
greatest  distance  is  WJZ;  Newark,  N.  J. — 2550  miles. 


my  opinion,  it  is  very  satisfactory,  quite  differ- 
ent from  the  crude  single-tube  affair  that  was 
my  first  attempt.  The  set  is  selective,  capable 
of  bringing  in  clearly  many  distant  stations,  and 
has  enough  power  to  fill  the  whole  house  with 
music  when  using  a  Type  C  Baldwin  phone 
at  the  end  of  a  three-foot  lacquer  horn.  The 
lacquer  horn  is  superior  to  metal  in  that  there 
is  no  metallic  sound  to  the  music  heard  through 
it.  Another  improvement  in  the  quality  of  the 
music  may  be  had  by  melting  a  very  small 
drop  of  sealing  wax  over  the  pin  through  the 
center  of  the  diaphragm  of  the  phone.  This 
tends  to  lessen  any  tendency  of  over-vibration, 
and  will  also  keep  the  pin  tight  in  thediaphragm. 

The  set  is  of  the  spider-web  coil  type,  consist- 
ing of  two  stages  of  radio  frequency,  detector, 
and  two  stages  of  audio  frequency.  All  con- 
trols, rheostats,  condensers,  coils  and  potentio- 
meters are  mounted  on  a  panel  of  J-inch  hard 
rubber,  9  inches  high  and  26  inches  long,  com- 
pletely shielded  with  .002  brass.  All  the  in- 
struments on  the  panel  are  well  insulated  from 
the  shield,  and  the  latter  grounded  to  the 
ground  lead.  A  series-parallel  switch  is  used 
in  the  antenna  circuit  to  switch  the  aerial 
condenser  from  series  to  parallel  for  long-wave 
reception,  and  a  like  switch  is  used  to  cut  the 
radio  frequency  in  or  out  as  desired.  The  latter 
switch  is  necessary  for  the  reception  of  signals 


The  "How  Far  Have  You  Heard?"  Contest 


235 


of  more  than  600  meters,  as 
the  R.  F.  transformers  will 
not  handle  waves  over  that 
length.  Separate  B  batteries 
are  used  for  the  radio  and 
audio  frequency,  but  a  single 
6-volt  A  battery  is  used  foi 
both.  Jacks  for  the  detector 
and  each  stage  of  audio  fre- 
quency are  supplied  for  use 
on  signals  from  stations  close 
enough  not  to  require  the  full 
power  of  the  set.  This  saves 
the  batteries  and  tubes  a 
little. 

The  tuning  is  controlled  by  two  condensers 
— a  43-plate  variable  in  the  primary  circuit  and 
a  23-plate  variable  and  vernier  in  the  secondary 
circuit — and  two  potentiometers,  one  used  as 
a  stabilizer.  A  word  about  condensers,  both 
fixed  and  variable.  From  my  experimenting 
with  different  kinds  and  makes  of  both  types 
of  condensers,  I  have  discovered  that  those 
whose  movable  and  stationary  plates  are  very 
close  to  each  other  are  not  as  practical  as  those 
having  the  plates  a  little  farther  apart  because 
of  the  fact  that  dust  particles  are  floating  in  the 
air  at  all  times,  and  some  of  these  settle  on  the 
plates  of  the  condensers.  In  time,  enough  of 
these  particles  may  collect  so  as  to  cause  some 
of  them  to  touch  each  other  as  the  plates  are 
moved,  thus  causing  a  discharge  between  the 
plates  of  the  condenser,  the  dust  particles  act- 
ing as  a  high  resistance  conductor.  If  this 
should  happen,  the  set  would  become  very 
noisy  and  would  cut  its  efficiency  very  mater- 
ially; so,  for  this  reason,  encased  condensers 
are  best.  Due  to  the  fact  that  there  are  no 
spring  contacts  to  come  loose  or  to  wear  out, 
variable  condensers  whose  plates  are  balanced 
have  been  found  to  be  more  efficient  for  lon- 
gevity and  hard  use.  Another  important  thing 
is  the  selection  of  fixed  condensers.  Paper- 
insulated  fixed  condensers  are  liable  to  puncture 
if  high  B  battery  voltages  are  being  used,  and 
when  this  happens  it  sounds  as  if  all  the  arc 
lights  and  X-Ray  machines  in  the  community 
were  inside  the  set!  From  some  few  expe- 
riences like  the  above,  I  have  found  that  mica- 
insulated  fixed  condensers  are  more  satisfac- 
tory. 

The  tubes  are  mounted  in  cascade,  back  of 
and  about  two  inches  away  from  the  panel. 
They  are  placed  behind  their  respective  rheo- 
stats so  as  to  keep  the  leads  from  the  latter  as 


THE  RECEIVER  BUILT  BY  MR.  HARRINGTON 

Whose  success  in  transcontinental  reception  can  be  attributed, 
in  large  measure,  to  soldered  connections  throughout  his  set 


short  as  possible,  and  all  the  connections  are 
soldered.  Too  much  stress  cannot  be  laid  upon 
the  importance  of  soldered  connections.  All 
joints  and  connections,  leads  to  transformer 
and  socket  binding  posts,  battery  binding  posts, 
etc.,  should  be  soldered.  There  will  be  no  "  rock- 
crushers"  or  "stamp  mills"  in  a  set  so  con- 
nected. In  order  to  keep  their  leads  as  short  as 
possible,  the  transformers  are  set  directly  be- 
hind the  tubes,  and  have  their  cores  at  right 
angles  to  each  other.  The  transformers  are 
separately  shielded  and  the  shields  grounded. 
A  C  battery  is  used  to  impress  a  heavier  nega- 
tive charge  on  the  grids  of  the  amplifier  tubes 
in  the  audio  frequency,  and  this  tends  to  cut 
out  distortion  and  also  to  increase  the  volume 
of  the  signals.  The  voltage  used  here  is  varied 
to  get  the  best  results,  sometimes  being  as  low 
as  1  \  volts  but  never  over  7!  volts.  90  volts 
on  the  plates  of  the  R.  F.  tubes,  18-23  on  'the 
detector,  and  90  on  the  A.  F.  amplifiers  bring 
the  best  results. 

Two  outside  aerials  are  available  for  use. 
One,  a  5-wire  inverted  L,  44  feet  long  and  65 
feet  high  with  a  fan  shaped  counterpoise  con- 
taining 350  feet  of  wire  is  very  efficient  on  the 
more  distant  stations.  The  other,  a  single 
wire  165  feet  long,  65  feet  high  at  one  end 
and  50  feet  at  the  other,  works  very  well  on 
the  local  and  near  distant  stations.  The  leads 
in  are  taken  from  the  higher  end  and  are  as 
short  as  possible.  For  reception  up  to  500 
miles,  where  great  strength  of  signals  is  not 
desired,  a  loop  aerial  is  used.  With  it  the  set 
becomes  ultra-sensitive.  Music  from  stations 
300  miles  away  using  a  reasonable  amount  of 
power  output  in  their  aerial,  comes  in  strong 
enough  to  operate  the  Baldwin  phone  and  be 
heard  over  the  entire  room.  Cunningham  301- 
A  tubes  are  used  throughout  the  set,  and  I 


236 


Radio  Broadcast 


TWO  RADIO,  DETECTOR,  AND  TWO  AUDIO 

C,  75-volt  batteries  for  biasing  A.F.  tube  grids;  Gi,  earth  ground;  G2,  capacity  ground  (counterpoise);  V,  de- 
tector tube  voltmeter;  SPi,  series-paralled  antenna  condenser  switch;  SP2,  switch  for  cutting  R.  F.  in  or  out; 
S,  stabilizer;  P,  A-battery  potentiometer;  L,  loop  which  may  be  used  instead  of  outside  antenna  when  desired 


have  found  them  to  give  very  good  results. 
These  tubes  are  not  critical  as  to  filament 
voltage,  although  5  to  5I  volts  on  the  filaments 
works  as  well  as  any  higher  voltage.  These 
tubes  "fry"  less  and  oscillate  more  freely,  than 
any  other  tube  I  have  used. 

Tuning  the  set  is  accomplished  as  follows: 
for  wavelengths  up  to  375  meters,  the  cor- 
rect size  coils  are  placed  in  the  coil-mountings 
(about  35  turns  in  the  primary,  50  in  the  sec- 
ondary, and  75  in  the  tickler).  The  bulbs  are 
turned  to  their  right  temperatures  and  the 
aerial  condenser  is  switched  to  series  with  the 
aerial,  and  the  R.  F.  switched  in.  The  primary 
condenser  is  then  turned  to  somewhere  between 
o  and  40  on  the  dial  (usually  about  25),  and 
the  secondary  condenser  is  slowly  rotated  from 
o  to  maximum  until  a  shrill  whistle  is  heard. 
The  stabilizer  is  then  adjusted  until  voice  or 
music  is  distinct  and  clear.  Usually  the  sec- 
ondary condenser,  vernier  and  stabilizer  must 
be  re-adjusted  slightly,  and  then  the  concert 
or  address  "picked  up"  may  be  enjoyed  to  the 
greatest  extent.  Moving  the  coils  and  chang- 
ing the  stabilizer  and  vernier  will  enable  a 


person  to  hear  different  stations  operating  on 
nearly  the  same  wavelength.  If  the  primary 
condenser  be  turned  farther  toward  maximum 
and  a  larger  coil  inserted  in  the  primary  cir- 
cuit, stations  of  different  wavelength  may  be 
brought  in.  For  400-meter  stations  I  have 
found  that  50  turns  in  the  primary  and  sec- 
ondary, with  100  turns  in  the  tickler  give  the 
best  results,  the  signals  being  clear  and  loud, 
with  a  minimum  of  interference  from  360-meter 
stationsand  amateur  stations.  Flat-wound  pan- 
cake coils  seem  to  give  quite  the  best  results. 

In  the  short  space  of  the  half-hour  in  the 
evening  while  local  broadcasters  are  quiet,  I 
have  been  able  to  tune  in  as  many  as  18  dif- 
ferent stations.  Those  within  500  miles  may 
usually  be  brought  in  while  local  broadcasters 
are  in  the  air,  with  no  interference  from  the 
latter.  This  is  especially  true  when  using  a 
loop  aerial.  The  loop  used  with  this  set  is 
two  feet  square  and  has  twelve  turns  of  wire. 

In  conclusion,  I  will  say,  that  for  one  who 
wishes  a  set  that  is  sensitive,  selective,  power- 
ful and  easy  to  operate,  this  set  gives  great 
satisfaction. 


REPORTS  FROM  OTHER  ENTRANTS  IN  THE  "HOW  FAR?"  CONTEST 


FINE  WORK  FROM  A  REMOTE  CORNER  OF  THE  U.S. 

MR.  LESTER  WITHERBY,  who  lives  in 
Ferndale,  Washington — a  hundred  miles 
north  of  Seattle,  near  the  Canadian  border,  has 
done  some  remarkable  receiving  with  a  3-circuit 
two-bulb  set,  for  which  he  wound  his  own 


multi-layer  coils.  His  list  of  stations  is  too 
long  to  publish  here,  but  his  three  greatest 
jumps  are  WGY,  Schenectady,  N.  Y.,  2,500 
miles;  NOF,  Anacostia,  D.  C,  2,475;  and 
KGU,  Honolulu,  2,300. 

Mr.  Witherby  has  supplied  the  following 
"dope,"  which,  with  the  photo  and  circuit 


The  "How  Far  Have  You  Heard?"  Contest 


diagram  shown,  should  enable  the  experienced 
radio  fan  to  build  a  similar  set  (the  3  coils  and 
coil  mounting  may,  of  course,  be  bought  if  de- 
sired) : 

"  My  set  is  a  home-made  one  and  consists  of  a 
detector  and  one  stage  of  audio-frequency.  It 
is  mounted  on  a  bakelite  panel  6|  inches  by 
1 5  inches. 

"  1  use  three  honeycomb  coils  of  35,  50  and 
75  turns  each,  in  the  primary,  secondary  and 
tickler  respectively,  with  a  43-plate  vernier 
condenser  across  the  secondary  coil. 

"The  only  thing  to  bother  about  my  set  was 
to  get  it  to  oscillate  on  400  meters  without  an 
extra  amount  of  current  on  the  detector.  To 
overcome  this  trouble,  I  placed  a  .001  mfd. 
fixed  condenser  across  the  primary  of  my  am- 
plifying transformer  which  helped  considerably 
in  cutting  down  the  filament  current. 

"  I  made  my  own  honeycombs  and  also  the 
mounting,  which  is  similar  to  a  Remler  mount- 
ing except  that  the  contact  is  made  with  spring 
brass  clips  instead  of  brass  plugs. 

"  In  tuning,  I  set  the  coils  nearly  closed,  get 
the  wave  with  the  condenser,  then  tune  in 
clearly  with  the  vernier  condenser  and  vernier 
rheostat.  One  thing  that  gives  me  lots  of 
volume  and  very  little  noise  is  a  large-ratio  (9 
to  1)  transformer. 

"My  aerial,  about  30 feet  high  and  150  feet 
long  including  lead-in,  is  made 
of  the  copper  ribbon-  from  the 
field  coil  of  a  Ford  magneto. 
It  works  fine  because  of  its 
extra  surface. 

"  The  set  is  wired  with  No. 
14  copper  wire,  and  all  joints 
are  soldered. 

"All  measurements  for  mile- 
age were  taken  on  a  Rand-Mc- 
Nally  &  Co.  copyrighted  map. 
This  map  checked  closely 
with  Cram's  official  radio  map. 

"  Being  located  in  the  very 
northwest  corner  of  the  United 
States  and  therefore  unable  to 
get  any  stations  north  or  west, 
1  consider  my  aggregate  mile- 
age better  than  the  same  mile- 
age at  some  central  point. 
Some  stations,  such  as  At- 
lanta, Birmingham,  New  Or- 
leans, etc.,  are  as  far  from 
Ferndale  as  they  are  from  any 
place  in  the  United  States." 


MR.  W1THERBY  S  SET  IS  SIMPLE 
But  it  has  reached  out  2500  miles 

YOUNGSTER  AMONG  THE  LEADERS 

ROSCOE  ROBINSON  of  Ponca  City,  Okla- 
homa, who  is  but  fourteen  years  old, 
has  run  up  an  aggregate  mileage  of  93,475. 
He  uses  a  Murad  Type  MA- 13  receiver  with  a 
loop  antenna.  Among  the  stations  he  hears 
are  KHJ,  Los  Angeles,  Calif.,  WGY,  Schenec- 
tady, N.  Y.,  WFI,  Philadelphia,  Pa.,  PWX, 
Havana,  Cuba,  KDZT,  Seattle,  Wash.,  CKKE, 
Toronto,  Ontario,  WDAL,  Jacksonville,  Fla., 
KUO,  San  Francisco,  Colif.,  CJCE,  Vancouver, 


W 


MR.  W1THERBY  S  HOOK-UP — A  GOOD  ONE  TO  TRY 


238 


Radio  Broadcast 


B.  C,  and  WGAD,  Ensenada,  P.  R.  He  has 
included  no  stations  within  i  50  miles  of  his  re- 
ceiving station,  and  Ensenada  is  his  best  single 
jump — approximately  2,000  miles. 

Henry  Duderstadt  .  of  Kansas  City,  Mo. 
has  heard  1  ro  stations  from  150  to  1,550  miles 
from  his  home,  and  his  aggregate  mileage  is 
69,980.  Mr.  Duderstadt  is  using  a  Grebe  CR-9. 
He  has  listed  but  7  stations  less  than  200  miles 
distant;  13,  between  200  and  300  miles;  7 
between  300  and  400;  20  up  to  500;  15  up  to 
600;  10  up  to  700;  8  up  to  800;  5  up  to  900;  2  up 
to  1 ,000;  3  to  1 , 100;  5  to  1 ,200;  1  to  1 ,300;  4  to 
1,400;  3  to  1,500,  and  4  up  to  1,600.  His  list 
would  make  a  pretty  good  broadcasting  direc- 
tory in  itself  and  it  has  been  sworn  to  before  a 
notary.  . 

Curtis  Herbert  of  Rutherford,  N.  J.  has 
heard  88  stations  from  180  to  3,200  miles 
distant  with  an  aggregate  mileage  of  69,501 
on  a  home-made  single-circuit  regenerative 
outfit.  His  longest  jump  is  Los  Angeles,  Calif. 
This  is  exceptionally  good  for  a  home-made 
outfit. 

On  a  modified  single-circuit  regenerative  out- 
fit employing  a  vacuum-tube  detector  and  one- 
stage  amplifier,  Mr.  Edwin  M.  Nissen  (Radio 
9EAM)  had  heard  77  stations  from  375  to  1 ,725 
miles  distant  from  his  home  in  Denver,  Colo. 
His  list  includes  stations  located  along  our 
Eastern  seaboard,  all  the  way  from  Boston  to 
Cuba,  along  our  southern  border  to  the  West 
Coast,  up  into  Canada  and  back  to  Boston. 

R.  P.  McElhiney  of  Madison,  Me.,  has 
received  concerts  from  24  states.  His  receiver 
is  a  single-circuit  regenerative  outfit  made  up  of 
standard  parts.  The  shortest  distance  on  his 
list  is  200  miles  and  his  greatest  jump  is  1,785, 
to  Fort  Worth,  Texas.  His  aggregate  mileage 
is  69,840. 

Rolland  R.  La  Pelle  of  Washington, 
D.  C,  using  a  two-tube  receiver  that  he  made 
himself,  lists  100  stations  from  175  to  2,300 
miles.  His  aggregate  mileage  is  56,905  and  his 
2,300  mile  jump  is  to  Los  Angeles,  Calif. 


A  NEAT  6-TUBE  SET  MADE   BY  DON  ROSS,  OF 


Among  the  contestants  who  are  below 
50,000  is  Daniel  Lamb  of  Mesa,  Ariz.,  who 
uses  a  home-made  single-circuit  regenerative 
outfit  and  has  heard  39  stations  from  200  to 
2,300  miles  distant.  His  aggregate  is  36,950. 
He  mentions,  however,  that  this  list  is  not 
complete  and  that  he  has  only  recorded  some  of 
the  best  distance  work  he  has  done.  Perhaps 
the  present  list  may  be  considerably  increased 
if  all  his  stations  are  included. 

Alex  H.  McKay,  of  Bradford,  Pa.,  using  a 
single-circuit  regenerative  receiver  and  two 
stages  of  audio-frequency  amplification,  has 
heard  72  stations  1 50  to  1 ,450  miles  distant  and 
his  aggregate  is  36,710.  His  1 ,450  mile  hop  is  to 
San  Antonio,  Texas. 

A.  J.  Wishart  and  L.  D.  Thorpe  of  Per- 
due, Saskatchewan  have  sent  in  a  joint  re- 
port of  34  stations  from  150  to  2,700  miles, 
with  an  aggregate  mileage  of  30,925.  They 
use  a  standard  three-circuit  regenerative  re- 
ceiver. 

Miss  Hazel  B.  Home  of  Montreal,  Quebec, 
using  an  Aeriola  Sr.  has  heard  47  stations  from 
225  to  1,575  miles  away,  and  her  aggregate 
mileage  is  30,070.  Miss  Horne  has  the  best 
aggregate  mileage  among  the  ladies,  and  we 
wonder  why  more  of  them  have  not  sent  in 
their  reports. 

Mr.  W.  H.  Croft,  Saskatoon,  Sask.  has  heard 
31  stations  185  to  1,500  miles  distant  and  his; 
aggregate  mileage  is  27,035.    That  makes  an 
average  mileage  for  the  31  stations  of  consider- 
ably better  than  800  miles. 

T.  J.  Forgy  of  New  Carlisle,  Ohio,  is  using  a 
three-circuit  receiver  of  the  type  used  by  Mr. 
Bedell  and  described  in  Radio  Broadcast  for 
January.  He  has  heard  44  stations  from  160 
to  1 ,900  miles  distant.  His  aggregate  mileage  is 
25,125.  **W        :  '      •  _ : 

Nelson  Brown  of  Southampton,  Ontario, 
also  uses  a  three-circuit  tuner  and  has  heard 
35  stations  ranging  from  180  to  1,500  miles. 
His  aggregate  is  20,740. 

Henry  S.  Sherman,  Jr.  who  is  but  14 
years  old,  uses  an  out- 
door antenna  with  a 
spider-web  regenerative 
outfit  that  he  built  himself. 
He  has  heard  35  stations 
from  250  to  1,950  miles  dis- 
tant. The  1,950  mile  jump 
is  KDKL,  Salt  Lake  City, 
Utah  and  his  aggregate 
ironwood,  mich.     mileage  is  19,210. 


WEAF's  New  Home 


THE  COMFORTABLE  RECEPTION  ROOM,  WITH  DOORS  LEADING  TO  BOTH  STUDIOS 


All  Boy  Scouts,  Attention! 


RADIO  BROADCAST  announces  a  contest,  ending  July  3 1 ,  1Q23,  to  determine  WHAT  BOY 
SCOUT  TROOP  HAS  DONE  OR  IS  DOING  THE  MOST  WITH  RADIO. 

Prizes  for  Winning  Articles 

FIRST  PRIZE:    CROSLEY  MODEL  X  4-TUBE  RECEIVER. 

This  receiver,  which  may  he  used  with  dry-cell  tubes  if  desired,  consists  of  detector,  one  stage  of 
tuned  radio-frequency  and  two  stages  of  audio-frequency  amplification.  {Advertised  in  Radio 
Broadcast). 

SECOND  PRIZE:    MUSIC  MASTER  LOUD  SPEAKER. 

This  is  the  new  loud  speaker  made  by  the  General  Radio  Corporation.  (A  picture  and  description 
of  it  appear  in  the  advertising  pages  of 

THIRD    PRIZE:  THREE 

The  WD-11  is  the  well-known- dry- 
Corporation.  {Filament  voltage  1.5, 
of  the  third  pri^e  may  have  UV-igg's 

A  YEAR'S  SUBSCRIPTION  TO 
given  as  prices  for  the  ten  next  best 

These  prices  will  be  awarded  to 
troop  may  delegate  one  of  its  members  to 

Rules  of  the  Contest 

/.  Articles  must  be  true  accounts  of  radio  with  relation  to  your  particular  troop:  what  you  have  done,  or  are 
doing,  or  both. 

2.  Every  article  must  he  written  by  a  Scout  or  by  more  than  one  Scout  belonging  to  one  troop. 

3.  Articles  should  be  between  500  and  woo  words  long. 

4.  Good  photographs  to  illustrate  the  article  will  count  50%  in  judging  contributions. 

5.  Typewritten  manuscript,  double-spaced,  is  desired,  though  not  required. 

6.  Address  contributions  to  Scout  Contest,  Radio  Broadcast,  Doubleday,  Page  &  Company,  Garden  City,  N.  Y. 

Scouts  have  done  splendid  work  in  maintaining  communication  by  radio  in  time  of  floods  and  disaster,  in 
copying  and  spreading  the  market  reports  transmitted  by  the  government  Farm  Bureaus,  in  training  themselves 
along  mechanical  and  electrical  lines,  and,  in  short,  in  using  radio  as  a  part  of  scout  work  in  a  way  consistent 
with  the  best  traditions  of  scouting.  What  have  you  to  tell  of  your  troop's  past  or'present  activities?  Get  your 
scribes  and  photographers  under  way  with  that  story  which  will  put  in  a  strong  bid  for  first  pri^e.  How  would 
a  receiver  with  three  stages  of  amplification  go  in  your  troop? 

Beginning  with  the  August  number  of  Radio  Broadcast,  the  best  articles  will' be  published.  The  winners 
will  be  announced  in  the  September  number,  and  unless  the  three  best  articles  have  been  previously  published, 
they  will  appear  in  that  issue. 


Radio  Broadcast). 

WD-11  VACUUM  TUBES, 
cell  tube  manufactured  for  the  Radio 
plate  voltage  22% — 45).    The  winner 
or  UV-201-A' s  if  he  prefers. 

• 

"RADIO  BROADCAST"  will  be 
contributions  in  this  contest. 

troops,  not  to  individuals,  although  any 
prepare  the  story. 


FIG.  I 

Standard  wavemeter  of  the  Bureau  of  Standards 


Reducing  the  Guesswork  in  Tuning1 


T 


How  the  Bureau  of  Standards  Will  Measure  the  Wavelengths  of 
Broadcasting  Stations  with  an  Accuracy  of  99.9%,  Making  it 
Possible  for  Any  One  to  Use  His  Receiving  Set  as  a  Wavemeter 

By  J.  H.  DELLINGER 

Chief,  Radio  Laboratory,  Bureau  of  Standards 


HE  good  results  already  appearing 
from  the  recommendations  of  the 
Second  National  Radio  Conference 
could  easily  be  wrecked  if  the  radio 
broadcasting  stations  and  other 
stations  should  not  operate  accurately  on  the 
frequencies  to  which  they  are  assigned.  One 
of  the  reasons  why  interference  has  been  the 
great  draw-back  to  progress  in  radio  has  been 
that  the  transmitting  stations  have  used  waves 
which  approximated  the  assigned  wavelength  or 
frequency  only  very  roughly  indeed.  Among 
its  numerous  tasks  of  standardization  and  re- 
search, the  Bureau  of  Standards  has  devoted 
itself  with  some  vigor  to  the  task  of  improving 
the  frequency  standards  of  the  country,  with 
the  result  that  there  is  every  prospect  that  the 
interference  situation  will  be  greatly  relieved 
from  now  on.  The  Bureau's  work  in  this 
direction2  has  been  directed  at  two  objectives: 

Published  by  permission  of  the  Director,  Bureau  of 
Standards. 

2Among  those  who  are  engaged  in  this  important  work, 
under  Dr.  Dellinger's  direction,  are  Mr.  E.  L.  Hall,  the 
Misses  F.  Kenyon  and  G.  Hazen,  Mr.  F.  W.  Dunmore, 
Mr.  F.  H.  Engel,  and  Mr.  H.  J.  Walls. 


increasing  the  accuracy  of  its  standards,  and 
making  these  standards  available  to  the  radio 
public. 

About  a  year  ago  the  Bureau  began  a  pro- 
gram of  work  which  would  materially  improve 
the  accuracy  of  its  radio-frequency  measure- 
ment. Prior  to  that  time  the  basic  wavemeter 
standards  were  based  entirely  on  circuits  made 
up  of  standard  capacities  and  inductances,  the 
values  of  which  were  either  calculated  or 
measured  at  low  frequencies.  These  standards 
were  prepared  with  great  care  and  precautions 
were  taken  to  avoid  errors  in  the  measurements, 
but  there  was  no  certainty  that  the  frequency 
basis  thus  established  could  be  relied  upon  to 
be  correct  within  less  than  i  per  cent.,  particu- 
larly for  the  very  high  radio  frequencies.  The 
work  that  has  been  done  recently  has  given  a 
new  basis  of  measurement,  resulting  from 
several  interesting  and  quite  independent 
methods  of  frequency  determination,  and  is 
much  more  accurate.  The  goal  set  in  this 
work  was  an  accuracy  of  99.9  per  cent.  The 
reason  why  this  degree  of  accuracy  is  important 
may  be  seen  from  a  brief  consideration  of  the 


242 


Radio  Broadcast 


frequency  assignments  to  broadcasting  stations. 
The  waves  used  by  the  broadcasting  stations 
are  spaced  10  kilocycles  apart  (3  meters  at  a 
wavelength  of  300  meters).  Thus  one  station 
is  on  990  kilocycles,  another  on  1000,  and 
another  on  1,010  kilocycles.  If  one  of  these 
is  inaccurately  adjusted  by  as  much  as  0.1  per 
cent,  this  would  mean  a  variation  of  1  kilocycle 
from  the  established  value.  The  next  station 
having  a  frequency  only  10  kilocycles  different, 
this  variation  of  1  kilocycle  is  decidedly  appreci- 
able in  comparison  with  the  10  kilocycle 
separation.  A  variation  of  the  frequency  of 
1  per  cent,  for  example,  would  be  a  variation  of 
10  kilocycles  and  could  cause  one  station  to  be 
using  exactly  the  wave  that  had  been  assigned 
to  another.  The  whole  success  of  American 
broadcasting  is  thus  tied  up  with  the  placing 
of  broadcasting  stations  on  the  correct  fre- 
quencies to  an  accuracy  approaching  99.9  per 
cent.  Since  receiving  sets  are  now  available  by 
which  an  individual  can  hear  the  stations  from 
all  over  the  United  States  on  the  same  night, 
the  importance  of  this  accuracy  is  apparent. 

The  basis  of  frequency  measurement  of  the 
Bureau  of  Standards  includes  absolute  fre- 
quency measurements  by  four  entirely  inde- 
pendent methods.    These  are: 

A.  Measurement  or  calculation  of  capacity 


fig.  2 

Lissajous  figures  giving  accurate  frequency  ratios 


and  inductance  of  carefully  constructed  stand- 
ard condensers  and  inductors. 

B.  Measurement  of  frequency  of  the  sound 
from  a  tuning  fork,  together  with  measurement 
of  ratio  of  such  frequency  to  radio  frequencies 
by  use  of  harmonics  from  an  electron  tube 
generator. 

C.  Measurement  of  frequency  of  the  sound 
of  a  tuning  fork,  together  with  measurement  of 
the  ratio  of  such  frequency  to  radio  frequencies 
by  the  use  of  Lissajous  figures  produced  by  the 
direct  application  of  the  two  frequencies  to  a 
cathode-ray  oscillograph.  This  method  is 
free  from  the  assumption  of  integral  ratios 
involved  in  the  harmonic  method  (B). 

D.  Measurement  of  the  actual  length  of  very 
short  waves  and  calculation  of  the  frequency 
from  this  and  the  known  velocity  by  the  rela- 
tion, f  =  v I  \.  (X  =  wavelength  in  meters). 
Ratios  of  frequencies  thus  measured,  to  lower 
radio  frequencies,  are  obtained  by  the  same 
general  methods  for  ratio  measurements  as  in 
B  and  C. 

These  four  methods  are  not  all  that  are 
theoretically  possible.  Another  one  that  could 
be  used  is  the  accurate  measurement  of  the 
speed  of  a  radio-frequency  alternator.  Every 
method  goes  back  ultimately  to  the  measure- 
ment of  a  time  interval. 

Method  A  was  the  first  method  to  be  used  by 
the  Bureau  of  Standards.  Where  this  system 
is  employed,  the  capacity  of  specially  designed 
condensers  are  measured  by  their  charge  and 
discharge  at  about  1  kilocycle.  The  inductance 
of  the  standard  inductors  is  measured  at  the 
same  frequency.  The  design  of  both  capacity 
and  inductance  standards  is  such  that  there  is 
no  appreciable  change  with  frequency.  The 
capacity  of  coil  and  leads  is  measured  by  the  use 
of  harmonics  as  described  on  page  100  of  the 
Bureau  of  Standards  Circular  74,  entitled 
"Radio  Instruments  and  Measurements." 
This  standard  wavemeter,  with  its  instruments 
for  indicating  resonance,  is  shown  in  Fig.  I.1 

Method  B  employs  the  frequency  of  a  tuning 
fork  as  the  starting  point,  measuring  the  ratio 
of  such  frequency  to  radio  frequencies  by  means 
of  harmonics  of  the  current  in  an  electron  tube 
generator.    The  use  of  harmonics  for  establish- 

1  Further  information  on  the  standard  wavemeter  is  given 
in  an  article  now  in  preparation  entitled,  "The  Standards 
of  Radio  Frequency  of  the  Bureau  of  Standards,"  by  Mr. 
E.  L.  Hall,  who  is  in  charge  of  radio  standards  and  testing. 
The  time  and  place  of  publication  of  that  article,  and  others 
referred  to  below,  will  be  announced  in  the  Radio  Service 
Bulletin. 


Reducing  the  Guesswork  in  Tuning 


ing  radio  frequency  ratios  has  been  described 
in  Circular  74,  page  103.  The  method  has 
been  especially  developed  by  Prof.  H.  Abraham 
whose  apparatus  is  known  as  the  multivibrator. 
The  multivibrator  has  not  been  set  up  in  the 
Bureau  of  Standards  laboratory,  but  has  been 
in  use  in  the  Naval  Radio  Research  Laboratory 
located  at  the  Bureau  of  Standards.  Compari- 
sons of  this  multivibrator  and  the  other 
methods  have  been  carefully  made  throughout 
the  range  from  18  to  3600  kilocycles. 

In  method  C,  the  frequency  of  a  tuning  fork 
is  carefully  measured  with  a  chronograph,  and 
ratios  of  this  to  frequencies  in  the  radio  range 
are  measured  by  the  use  of  the  cathode-ray 
oscillograph.  This  device  is  a  special  kind 
of  vacuum  tube  in  which  a  beam  of  cathode 
rays  produces  a  spot  of  light  on  a  fluorescent 
screen  placed  in  the  end  of  the  tube.  When 
the  beam  is  deflected  the  spot  moves  across  the 
fluorescent  screen.  Provision  is  made  for 
deflecting  the  beam  in  two  directions  at  right 
angles  to  each  other  by  two  pairs  of  small 
condenser  plates  to  which  controlled  voltages 
may  be  applied.  When  two  alternating  volt- 
ages are  applied  which  have  frequencies  related 
by  a  simple  ratio,  the  spot  of  light  traces  out  a 
Lissajous  figure  on  the  fluorescent  screen.  The 
shape  of  the  Lissajous  figure  tells  the  ratio; 
the  examples  in  Fig.  2  show  this.  The  two 
pairs  of  deflecting  plates  are  connected  in 
parallel  with  the  condensers  of  two  independent 
generators  of  currents  of  audio  or  radio  fre- 
quency. In  the  first  step  of  the  standard- 
ization process,  the  "low-frequency"  generator, 
Fig.  3,  is  an  electron  tube  generator  of  approxi- 
mately 1  kilocycle,  the  frequency  of  which  is 
determined  by  the  tuning  fork.  The  "high- 
frequency"  generator  is  an  electron-tube 
generator  having  a  frequency  anywhere  from 
1 1  to  22  times  this,  the  frequency  being  varied 
until  successive  Lissajous  figures  appear  on  the 
screen.  The  frequency  ratio  thus  measured  is 
extremely  accurate,  being  in  all  cases  closer 
than  the  accuracy  of  setting  of  the  standard 
wavemeter,  which  is  tuned  to  the  frequency 
of  the  "high-frequency  "  generator.  The  method 
was  largely  developed  by  Mr.  R.  T.  Cox.  Its 
use  will  be  described  in  a  separate  publication 
entitled,  "  Primary  Radio  Frequency  Standard- 
ization by  Use  of  the  Cathode-Ray  Oscillo- 
graph," by  Misses  F.  Kenyon  and  G.  Hazen. 

In  method  D,  a  direct  measurement  of  the 
wavelength  of  short  waves  on  wires  is  made  by 
coupling  a  short-wave  generating  set  (Fig.  4)  to 


243 


PARALLCL  WIREUJ 


FIG.  3 

Showing  connections  of  generators  whose  frequencies 
are   compared    by    the   cathode-ray  oscillograph 

a  loop  of  wire  connected  to  one  end  of  two  long 
parallel  wires  approximately  4  centimeters 
apart.  A  short  wire  at  right  angles  to  the 
parallel  wires,  and  containing  a  thermo-element 
is  moved  along  the  parallel  wires  and  the 
positions  of  successive  maxima  of  current  are 
noted.  The  distances  between  these  positions 
are  each  a  half  wavelength.  They  are  measured 
with  a  steel  tape,  and  agree  within  a  few 
hundredths  of  one  per  cent,  for  the  wavelengths 
used,  9  and  16  meters.  These  wavelengths 
correspond  to  frequencies  of  approximately 
33,000  and  19,000  kilocycles  respectively. 
These  frequencies  are  not  so  high  as  to  be 
beyond  practical  application  in  radio  telegra- 
phy and  telephony.  Experiments  at  the 
Bureau  have  shown  how  to  produce  them  and 
to  use  them  for  communication  as  well  as  for 
measurements. 

The  method  of  harmonics  has  been  used 
to  step  down  from  the  very  high  frequencies 
thus  produced  and  measured  to  radio  frequen- 
cies in  the  whole  range  down  to  340  kilocycles. 
This  is  done  by  placing  between  generators  I 
and  II  (Fig.  5)  a  receiving  set  tuned  to  the 
frequency  of  generator  I  which  produces  the 
current  in  the  parallel  wires.  Generator  1 1  is 
an  auxiliary,  the  frequency  of  which  is  varied 
until  one  of  its  harmonics  approaches  the 
frequency  of  generator  I.  The  frequency  of 
Generator  II  is  adjusted  until  the  beat  note 
heard  in  the  receiving  set  becomes  zero.  The 
wavemeter  is  meanwhile  tuned  to  the  frequency 
of  the  generator  1 1 .  The  frequency  for  that 
setting  of  the  wavemeter  is  then  the  frequency 
obtained  from  the  wavelength  measured  on  the 
parallel  wires,  divided  by  the  number  of  the 


244 


Radio  Broadcast 


fig.  4 

Generator,  detecting  instrument,  and  end  of  paral- 
lel wires  used  to  measure  very  high  frequencies 


harmonic.  The  measurement  of  these  very 
high  frequencies  and  establishment  of  the 
frequency  basis  by*  this  method  is  described  in 
a  paper  prepared  by  Messrs.  F.  W.  Dunmore 
and  F.  H.  Engel  entitled,  "A  Method  of 
Measuring  Very  Short  Wave  Lengths  and  Their 
Use  in  Frequency  Standardization." 

The  step  down  from  the  very  high  frequen- 
cies to  some  of  the  more  commonly  used  radio 
frequencies  can  also  be  made  by  the  cathode- 
ray  oscillograph,  as  described  above,  obtaining 
a  Lissajous  figure  directly  between  the  very 
high  frequency  and  a  lower  one  from  an  aux- 
iliary generator,  the  latter  frequency  being 
measured  by  the  wavemeter.  The  method 
is  difficult  at  such  high  frequencies,  and  the 
work  is  still  in  progress. 

The  results  of  the  independent  establishment 
of  the  frequency  basis  by  methods  A,  B,  C,  and 
D  have  been  intercompared  and  the  order  of 
agreement  is  o.i  per  cent,  to  0.2  per  cent. 
When  the  present  series  of  measurements  is 
completed,  the  Bureau  of  Standards  frequency 
basis  will  be  certainly  accurate  well  within  0.1 
per  cent.  This  frequency  basis  extends  from 
3.5  to  33,000  kilocycles. 

While  an  accuracy  of  o.  1  per  cent,  is  all  that 
has  been  sought,  for  present  needs,  this  will 
clearly  not  be  adequate  for  the  future.  I't  is 
highly  desirable  for  some  purposes  to  place  a 
heterodyne  receiving  set  on  a  definite  pre- 


determined frequency  with 
great  accuracy.  It  would  be 
possible  to  recognize  trans- 
mitting stations  by  the  beat 
note  produced  in  such  a  het- 
erodyne receiving  set.  This 
is  important  for  certain  Navy 
requirements.  In  order  that 
the  beat  note  may  not  vary 
from  the  pre-determined 
value  by  more  than,  say  100 
per  second,  this  means  that 
the  station  which  it  is  desired 
to  receive  should  have  its  fre- 
quency adjusted  accurately 
to  tV  of  a  kilocycle  which  is 
0.0 1  per  cent,  for  a  frequency 
of  1,000  kilocycles.  It  will 
be  quite  possible  in  the  next 
year  or  two  to  attain  this 
accuracy  (0.0 1  per  cent.) 
through  further  series  of  care- 
ful measurements  and  partic- 
ularly by  improvements  in 
the  frequency  standards  and  methods  of  indi- 
cating resonance. 

The  frequency  standards  have  in  past  years 
been  made  available  to  the  country  only 
through  the  standardization  of  wavemeters  at 
the  Bureau  of  Standards.  This  service  is  now 
extended  through  the  transmission  of  standard 
frequency  signals  and  through  measurements 
at  the  Bureau  of  the  frequency  of  various 
transmitting  stations.  Only  a  small  amount 
of  direct  wavemeter  standardization  can  be 
done  by  the  Bureau.  Because  of  the  Bureau's 
limited  personnel,  it  has  been  necessary  to 
restrict  tests  of  wavemeters  and  other  appa- 
ratus solely  to  important  standards.  The 
transmission  of  signals  of  standard  frequency, 
however,  which  was  begun  in  March  of  this 
year,  places  the  frequency  standards  in  the 
hands  of  all  who  care  to  use  them.  These 
signals  are  sent  out  approximately  monthly, 
with  special  repetitions  weekly  during  May 
and  June,  1923.  Starting  at  1 1  p.  m.,  so  as  not 
to  disturb  broadcast  programs,  some  eight  or 
ten  standard  frequencies  are  transmitted,  the 
intervals  between  transmissions  on  the  particu- 
lar frequencies  being  approximately  1 5  minutes. 
Announcements  are  given  both  in  radio  tele- 
phony and  in  continuous-wave  telegraphy,  and 
the  standard  frequency  is  transmitted  as  a 
series  of  long  dashes  and  the  letters  WWV. 
Methods  by  which  these  waves  can  be  received 


Reducing  the  Guesswork  in  Tuning 


245 


and  wavemeters  standardized  are  very  simple. 
Information  on  this  matter  is  given  in  Bureau 
of  Standards  Letter  Circular  No.  92,  a  limited 
supply  of  which  is  available  at  the  Bureau  of 
Standards,  Washington,  D.  C.  The  standard 
frequency  signals  are  transmitted  with  an 
electron  tube  set  rated  at  1  KW,  having  a 
radiation  of  approximately  1 50  meter-amperes. 
The  schedules  of  transmission  are  announced 
in  the  newspapers  and  in  the  Radio  Service 
Bulletin.  The  transmission  and  utilization 
of  the  standard  frequency  signals  are  further 
described  by  an  article  in  preparation  by  Mr. 
H.J.  Walls,  entitled,  "  Radio  Signals  of  Stand- 
ard Frequency." 

These  signals  are  received  and  used  through- 
out the  United  States  east  of  the  Mississippi 
River.  No  permanent  means  have  as  yet 
been  provided  for  extending  this  range  to  cover 
the  western  part  of  the  United  States.  One 
method  that  may  be  used  is  the  transmission 
of  signals,  the  frequency  of  which  is  kept  con- 
stant for  a  certain  number  of  minutes,  by  a 
Mid-Western  broadcasting  station.  Measure- 
ments of  this  transmission  can  then  be  made 
by  any  one,  using  the  same  methods  as  are 
used  for  receiving  the  Bureau  of  Standards 
signals  of  standard  frequency.  The  measure- 
ments will  simultaneously  be  made  by  the 
Bureau  of  Standards  and  the  values  so 
measured  will  be  announced  by  the  Bureau. 

A  final  method  of  supplying  frequency 
standards  uses  the  ether  itself  as  a  wavemeter. 
The  transmitting  stations  operating  on  definite 
frequencies  are  the  points  on  this  wavemeter. 
Broadcasting  and  other  stations  will  more  and 
more  from  now  on  utilize  a  radio  frequency 
indicator  to  assure  operation  on  the  assigned 
frequency  every  time  they  transmit.  Measure- 
ments of  the  actual  transmitted  frequencies  of 
various  stations  are  made  from  time  to  time 
at  the  Bureau  of  Standards.  When  these 
measurements  for  a  given  station  show  great 


DLFLE.CTING  PLATtS 
OF  CATHODE. -RAY 
OSCILLOGRAPH 


FIG.  5 

Arrangement  of  apparatus  for  step- 
ping down  from  very  high  frequencies 

constancy,  and  the  station  is  known  to  use  a 
suitable  frequency  indicator,  so  that  the 
Bureau  is  convinced  that  the  station's  operat- 
ing wave  can  be  used  as  a  frequency  standard, 
the  Bureau  will  so  announce.  These  announce- 
ments will  probably  be  made  in  the  Radio 
Service  Bulletin.  The  transmissions  from  such 
stations  can  then  be  used  as  known  points  on 
the  ether  wavemeter. 

Summarizing,  means  have  been  provided 
whereby  accurate  frequency  adjustment  of 
radio  stations  is  possible.  Great  improve- 
ments have  been  made  in  the  primary  fre- 
quency standards  and  in  their  availability  to 
the  public.  This  will  of  itself  remove  a  large 
portion  of  existing  radio  interference  and  make 
it  possible  to  realize  the  benefits  of  the  new 
frequency  allocations  recommended  by  the 
Second  National  Radio  Conference.  It  seems 
quite  certain  that  before  long  the  ether  itself 
will  be  a  standard  wavemeter  with  the  frequen- 
cies of  a  number  of  the  transmitting  stations 
as  its  fixed  points. 


Next  Month!    The  Ultimate  Receiver 

Mr.  Walter  Van  B.  Roberts,  whose  articles  "A  Single-Tube  Loop  Set  in  a  Brief  Case"  and  "Operating 
a  Loud  Speaker  on  One  Tube,  Without  Batteries"  appeared  in  our  May  and  June  issues,  respectively,  is  pre- 
paring another  article — just  as  interesting  and  even  more  important — for  our  August  number.  In  building 
the  particular  kind  of  super-heterodyne  receiver  which  he  is  going  to  describe,  Mr.  Roberts  has  incor- 
porated suggestions  from  the  best  technicians  of  to-day.  Although  having  but  two  wavelength  controls, 
this  receiver  is  to  combine  the  best  there  is  in  the  super-heterodyne,  the  neutrodyne  and  inverse-duplex 
methods.  With  a  laboratory  model,  Mr.  Roberts  is  hearing  KFI  and  KHJ  (from  Princeton,  N.  J.)  on  a  loop 
and  five  tubes.  We  know  of  no  receiver  that  exists  which  will  compare  in  selectivity,  long  range  and  ease 
of  operation  with  the  one  which  Mr.  Roberts  will  describe  in  Radio  Broadcast  for  August. — The  Editor. 


Recent  Broadcasters  in  New  York  Studios 


S.  L.  ROTHAPFEL  FILLING  THE  AIR  WITH  FUN 

He  receives,  on  an  average,  1500  letters  a  week  from 
listeners-in  who  enjoy  his  witty  announcements  between 
selections  broadcasted  from  WEAF  via  the  Capitol 
Theatre,  of  which  he  is  the  Director 


©  Underwood  &  Underwood 

FRIEDA  HEMPEL  SINGS  "HOME  SWEET  HOME" 

As  part  of  the  celebration  of  the  100th  anniversary 
of  John  Howard  Payne,  creator  of  the  best-known 
song  in  the  world.    In  the  picture  Miss  Hempel  is  shown 
at  WIZ's  Waldorf  Astoria  studio 


THREE  RADIO  CORPORATION   PRINCIPALS  AT  THE  OPENING  OF  RADIO  BROADCAST  CENTRAL 
Left  to  right:    Mr.  Owen  D.  Young,  Chairman  of  the  Board  of  Directors;  Dr.  Alfred  N.  Goldsmith,  Director  of 
Research,  and  Major-General  James  G.  Harbord,  President  of  the  Radio  Corporation  of  America.    Their  speeches  marked 
the  opening  of  the  Aeolian  Hall  stations,  WJZ  and  WJY,  on  May  14th 


Dry  Cells  and  UV-199's 


By  E.  E.  HORINE 

National  Carbon  Company,  Inc. 


THE  UV-199  vacuum  tube  is  the 
latest  and  smallest  member  of  the 
Radiotron  family.  The  men  respon- 
sible for  its  development,  realizing 
the  handicaps  of  the  storage  battery 
for  radio  receiving,  have  made  it  a  dry  cell 
tube.  And  while  the  voltage  required  to  oper- 
ate this  tube  is  higher 
than  for  other  dry-cell 
tubes,  it  is  so  sparing 
of  current  that  under 
certain  circumstances 
it  is  entirely  feasible 
to  operate  it  from  an 
A  battery  made  up  of 


flashlight  cells! 

This  remarkable  de- 
crease in  filament  en- 
ergy, compared  with 
storage  battery  tubes, 
has  not  been  accom- 
plished at  a  sacrifice 
of  other  desirable  fea- 
tures. As  a  matter 
of  fact,  the  electron 
emission  from  the  tiny 
UV-199  filament  is 
greater  than  from  the 
husky  filament  used  in 
the  UV-201 ,  which  re- 
quires 1  ampere  at  5 
volts  for  normal  oper- 
ation. This  gives  the 
UV-199  somewhat 
better  characteristics 
as  an  amplifier,  be- 
cause with  greater 
electron  emission, 
larger  B  battery  en- 
ergy is  made  available 

for  the  operation  of  the  telephone  receivers. 

Prior  to  the  introduction  of  the  UV-199, 
about  the  only  dry-cell  vacuum  tube  available 
to  the  public  was  the  WD-i  1 .  This  was  really 
the  first  tube  put  out  which  gave  successful 
results  on  dry  cells.  The  phenomenal  popular- 
ity of  the  WD- 1 1  is  due  to  its  ability  to  use 
dry  cells,  with  advantages  of  low  cost,  relia- 


Do  You  Know 


Why  it  is  more  economical  to  use  three  dry 
cells  rather  than  two,  to  operate  a  UV-199 
tube,  although  the  rated  filament  voltage  of 
the  tube  is  3,  and  three  dry  cells  in  series  de- 
liver 4§  volts? 

Why  it  is  more  economical  to  use  three  dry 
cells  than  four,  even  though  four  permit  each 
cell  to  be  used  for  a  longer  period? 

Why,  with  199's,  it  is  best  to  use  large  B 
batteries,  except  for  portable  sets,  in  which 
lightness  comes  first  in  importance  and  oper- 
ating cost  comes  second? 

What  the  "cut  off"  voltage  of  dry  cells  is, 
and  how  it  governs  your  operating  expense? 

Why  it  is  more  economical  to  use  large  dry 
cells  than  those  of  the  flashlight  variety  for 
your  A  battery,  although  the  voltage  rating 
of  each  is  the  same? 

Why,  when  operating  one,  two,  or  three  199's 
from  three  cells,  you  should  use  a  30-,  20-, 
or  10-ohm  rheostat  respectively? 

These  facts  and  others  are  thoroughly  and 
interestingly  described  in  this  article.  In 
presenting  this  work  of  Mr.  Horine's  to  you, 
Radio  Broadcast  believes  it  is  performing 
a  valuable  service.  This  is  the  type  of  article 
you  will  want  to  read  at  once,  to  be  thoroughly 
posted  on  the  UV-199  tube;  and  you  will  do 
well  to  keep  it  handy  for  future  reference.— 
The  Editor. 


bility,  freedom  from  attention,  and  ease  of 
renewal.  It  is  not  surprising,  therefore,  that 
the  WD- 1 1  should  prove  to  be  the  forerun- 
ner of  the  dry-cell  class  of  tubes. 

The  filament  of  the  UV-199  differs  somewhat 
from  that  of  the  WD-i  1  in  its  electrical  char- 
acteristics, in  that  the  UV-199 1S  what  we  might 
call  a  high-voltage, 
low-current  tube, 
while  the  WD-i  1  is 
a  low-voltage,  high- 
current  tube.  Al- 
though both  tubes 
were  designed  to  uti- 
lize the  energy  of  dry 
cells,  this  outstanding 
difference  in  filament 
characteristics  makes 
it  necessary  to  employ 
different  battery  con- 
nections for  the  two 
tubes. 

The  current  required 
by  the  UV-199  tube  is 
.060  ampere  (60  milli- 
amperes).  The  voltage 
necessary  to  force  this 
current  through  the 
filament  is  3.0  volts, 
and  in  order  to  get 
this  voltage,  three  dry 
cells  connected  in  se- 
ries must  be  employed. 
Herein  lies  what  to 
some  is  considered  a 
discrepancy.  It  is  gen- 
erally known  that  the 
voltage  of  an  unused 
dry  cell  is  1.5  volts. 
Actually,  it  is  usually 
in  excess  of  this  figure,  sometimes  running  as 
high  as  1.6  volts  in  new  cells,  but  for  conven- 
ience, and  to  employ  round  numbers,  it  is 
usually  stated  as  being  1.5  volts.  Since  the 
UV-199  requires  only  3.0  volts,  the  question 
naturally  arises,  "Why  is  it  necessary  to  use 
three  dry  cells?    Why  not  two?" 

It  must  be  remembered  that  one  of  the  char- 


248 


Radio  Broadcast 


< 


5 


1 

I 

J 

tO 

1 

g 

CD 

> 

\ 

\ 

2Mou 

1 — M — h- 

_4Hours  per  doy. 

0       .05       .10       .15      .20      .25      .30      .35     .40      .45      .SO  .55 

Current  Drain  -  Ai^pcrc&. 


FIG.  I 

Illustrating  how  different  current 
drains  affect  the  capacity  of  a  dry  cell 

acteristics  of  dry  cells  is  that  the  voltage  drops 
slightly  when  current  is  drawn  from  them.  The 
nominal  figure  of  1.5  volts  per  cell  is  what  is 
known  as  the  "open  circuit  voltage";  that  is, 
the  voltage  of  the  cell  when  delivering  no  cur- 
rent. As  soon  as  the  cell  is  connected  to  any 
device  which  draws  current  from  it,  a  different 
voltage,  called  the  "closed  circuit  voltage"  is 
obtained.  The  closed  circuit  voltage  of  a  dry 
cell  is  always  less  than  the  open  circuit  voltage. 

Obviously,  it  is  the  closed  circuit  voltage  of 
the  cell  that  we  are  primarily  interested  in. 
And  while  a  battery  made  v:  of  two  dry 
cells  connected  in  series  will  have  an  open 
circuit  voltage  of  3  volts,  the  minute  such  a 
battery  begins  delivering  current  to  one  or 
more  UV-199  tubes  the  voltage  will  drop  to 
something  under  3  volts,  which  is  less  than  that 
required  by  the  tube  for  satisfactory  operation. 

Another  important  reason  for  using  a  battery 
of  three  cells  connected  in  series  for  UV-199 
tubes  lies  in  the  matter  of  service  obtainable 
from  the  cells.  As  more  and  more  energy  is 
drained  day  after  day  from  them,  the  voltage 
gradually  drops,  until  eventually  the  available 
closed  circuit  voltage  is  just  equal  to  that  re- 
quired by  the  tube.  Any  further  withdrawal 
of  energy  will  reduce  the  cell  voltage  to  a  point 
lower  than  that  required  by  the  tube,  and  un- 
satisfactory operation  will  result.  It  is  evident 
that  the  lower  this  permissible  minimum  voltage 
(called  the  "cut-off  voltage"),  the  more  energy 
may  be  obtained  from  the  cells.  The  cut-off 
voltage  is  determined  by  the  electrical  charac- 
teristics of  the  filament,  which,  in  the  case  of 
the  UV-199,  's  3-°  volts. 

Therefore,  when  three  cells  are  used,  the 
range  through  which  they  can  be  worked  is  the 


difference  between  the  initial  4.5  volts  and  the 
final  3.0  volts,  which  is  1 . 5  volts  for  the  battery, 
or  .5  volt  per  cell.  On  light  current  drains,  a 
cut-off  of  1 .0  volt  per  cell  is  sufficiently  low  to 
insure  obtaining  a  major  portion  of  the  total 
energy  originally  stored  in  the  cell,  whereas,  if 
the  cut-off  is  made  1.5  volts,  which  would  be 
the  case  if  only  two  cells  were  used,  the  amount 
of  service  obtainable  would  be  very  small, 
indeed. 

On  account  of  the  extremely  small  current 
taken  by  the  UV-199  tube,  filament  rheostats 
having  much  more  resistance  than  common 
must  be  employed.  If  the  voltage  of  a  new 
dry-cell  battery  is  4.5  volts,  the  rheostat  must 
be  able  to  absorb  1.5  volts  with  a  current  of 
only  60  milliamperes  flowing  through  it.  This 
immediatelyestablishes  theminimum  resistance 
necessary  at  25  ohms,  but  in  order  to  provide 
a  reasonable  factor  of  safety,  and  to  allow  for 
flexibility  in  making  adjustments,  a  rheostat 
having  at  least  30  ohms  should  be  used. 

The  greatest  amount  of  service  from  the  bat- 
tery will  be  obtained  by  always  adjusting  the 
filament  rheostat  as  close  to  the  '"off"  position 
as  possible,  consistent  with  good  performance. 
Incidentally,  this  method  of  control  will  also 
result  in  prolonging  the  life  of  the  tube. 

When  so  used,  the  filament  rheostat  can  be 
looked  on  as  a  rough  indicator  of  the  condition 
of  the  battery.  With  new  cells,  it  will  be  neces- 
sary to  move  the  rheostat  only  a  very  short 
distance  away  from  the  "off"  position.  As  the 
voltage  of  the  cells  is  reduced  through  service, 
the  handle  must  be  moved  farther  and  farther 
over  to  obtain  good  results,  until  finally,  it 
must  be  thrown  all  the  way  over.  This  is  an 
indication  that  the  voltage  of  the  dry  cells  has 
fallen  to  the  voltage  of  the  tube,  and  when  this 
happens,  the  cells  are  exhausted  and  should  be 
discarded  and  new  ones  installed. 

The  capacity  of  a  dry  cell  is  measured  in 
ampere-hours,  the  same  as  a  storage  battery. 
An  ampere-hour  is  the  amount  of  electricity 
taken  from  a  battery  when  a  current  of  one 
ampere  flows  for  one  hour,  or  f  ampere  for  four 
hours,  or  §  ampere  for  eight  hours,  etc.  It  is 
always  obtained  by  multiplying  the  time  in 
hours  by  the  current  in  amperes. 

It  is  impossible  to  state  the  capacity  of  a  dry 
cell,  unless  all  the  conditions  under  which  the 
cell  will  work  are  known.  The  question, 
"What  is  the  capacity  of  a  dry  cell?"  is  quite 
similar  to  that  old  one,  "  How  high  is  up?"  It 
is  as  easy  to  answer  one  as  the  other. 


Dry  Cells  and  UV-199's 


249 


There  are  three  major  factors,  each  having 
an  important  bearing  on  the  capacity  of  a  dry 
cell,  and  all  three  are  under  the  control  of  the 
user.  They  are:  the  cut-off  voltage,  the  cur- 
rent drain,  and  the  average  number  of  hours 
the  cells  are  used  daily. 

just  how  can  the  user  control  these  factors? 
Take  the  cut-off  voltage.  This,  in  connection 
with  the  UV-199  tube,  is  determined  by  the 
number  of  cells,  connected  in  series,  used  to 
operate  the  tube.  For  example,  the  tube  volt- 
age is  3.0  volts.  If  two  cells  are  used,  the  cut- 
off for  the  two  cells  is  3.0  volts,  or  1.5  volts 
per  cell.  With  three  cells,  the  cut-off  becomes 
1 .0  volt  per  cell,  and  with  four  cells  it  is  f  of  a 
volt  per  cell.  In  general,  the  lower  the  cut-off 
voltage,  the  greater  the  capacity  of  the  cell,  but 
in  this  case,  it  is  inadvisable  to  reduce  the  cut- 
off of  I  of  a  volt  by  using  four  cells,  for  two 
reasons.  First,  the  cost  of  a  fourth  cell  is  a 
33^  per  cent,  increase  over  the  cost  of  three 
cells,  while  the  extra  amount  of  service  obtained 
by  using  four  cells  is  less  than  33^  per  cent, 
greater  than  from  three  cells.  In  other  words, 
it  is  not  economical.  Secondly,  there  are  no 
filament  rheostats  generally  available  having 
sufficient  resistance  to  absorb  the  extra  voltage 
of  the  additional  cell.  As  far  as  the  UV-199 
tube  is  concerned,  therefore,  the  cut-off  be- 
comes established  at  1.0  volt  per  cell. 

The  effect  of  different  current  drains  on  the 
capacity  of  a  dry  cell  is  somewhat  involved. 
In  general,  the  smaller  the  current,  the  greater 
the  capacity,  but  this  is  true  only  within  certain 
limits.  If  the  current  taken  from  the  cell  is 
too  small,  the  time  required  to  exhaust  it  is  so 
great  that  the  factor  of  natural  depreciation 
becomes  active,  thereby  reducing  the  capacity. 
If  the  current  is  too  great,  the  capacity  is  again 
reduced,  due  to  the  lowered  battery  voltage. 
So,  in  choosing  a  current  drain  for  dry  cells, 
one  must  be  taken  which  is  somewhere  between 
these  two  extremes.  It  is  necessary  to  choose 
between  a  heavy  current,  which  discharges  the 
cell  rapidly,  but  reduces  its  capacity,  and  a  very 
light  drain  which  prolongs  the  time  of  service, 
but  also  reduces  the  capacity.  On  radio  loads, 
where  current  is  drawn  from  the  cells  for  an 
average  of  two  or  more  hours  per  day,  this 
happy  medium  occurs  somewhere  in  the  neigh- 
borhood of  f  ampere. 

The  two  curves  shown  herewith  (Fig.  1)  serve 
to  illustrate  how  different  current  drains  affect 
the  capacity  of  a  dry  cell.  The  solid  curve 
shows  the  capacity  of  dry  cells  when  delivering 


current  two  hours  per  day,  and  the  dotted  curve 
the  capacity  when  the  cells  were  operated  four 
hours  per  day.  Both  curves  represent  the 
capacity  of  a  dry  cell  to  a  cut-off  of  1.0  volt, 
and  are  the  average  results  obtained  by  testing 
a  large  number  of  different  makes  of  cells.  It 
is  not  intended  that  the  figures  given  on  this 
chart,  or  in  the  discussion  of  it,  be  taken  liter- 
ally as  an  absolute  measure  of  the  capacity  of  a 
dry  cell.  They  are  merely  intended  to  give 
an  approximate  idea  of  what  the  average  user 
may  expect  from  the  usual  general-purpose  dry 
cells  when  used  to  operate  UV-199  tubes. 
Some  operators  will  obtain  greater  capacity 
than  indicated,  and  others  will  obtain  less,  de- 
pending on  their  skill  and  the  conditions  of 
operation. 

It  will  be  seen  that  in  both  cases,  maximum 
capacity  is  obtained  at  a  current  drain  of  about 
one-eighth  (.125)  ampere.  At  smaller  drains 
than  this,  the  capacity  falls  off,  due  to  the 
natural  depreciation  of  the  cell,  and,  as  is  to 
be  expected,  the  decrease  in  capacity  is  greater 
for  the  cells  which  were  in  use  only  two  hours 
per  day,  because  the  length  of  time  required 
to  exhaust  them  was  so  much  greater.  Thus, 
at  a  current  drain  of  .06  ampere  (the  current 
taken  by  one  UV-199  tube)  the  capacity  at 
2  hours  per  day  was  21  ampere-hours,  which 
means  that  the  number  of  hours  service  ob- 
tained was  350.  Since  the  cells  were  discharged 
only  two  hours  per  day,  it  required  175  days, 
or  approximately  six  months  to  complete  the 
test.  In  the  case  of  the  4  hour  per  day  cells, 
the  capacity  was  26.4  ampere-hours,  which  was 
440  hours  of  service.  But  since  these  cells 
were  in  use  4  hours  per  day,  the  test  only 
lasted  1 10  days,  or  about  3§  months  instead  of 
six,  and  it  is  this  shorter  time  which  explains 
the  increase  in  capacity. 

Although  it  is  in  the  power  of  the  user  of  a 


TO  RECEIVING  SET 


FIG.  2 

Three  dry  cells  connected  in  series.    This  is  the  most 
economical  A  battery  for  sets  employing  from  one  to 
three  UV-199  tubes 


25° 


Radio  Broadcast 


radio  set  to  regulate  the  number  of  hours  of 
service  each  day,  it  is  unreasonable  to  expect 
him  to  do  it.  Under  certain  conditions,  greater 
capacity  will  be  obtained  from  dry  cells  by 
reducing  the  number  of  hours  they  are  in  use 
daily,  but  can  you  imagine  a  radio  enthusiast 
shutting  down  his  set  at  8:57  p.  m.,  right  in  the 
middle  of  a  good  program,  merely  because 
by  so  doing  he  will  be  adding  a  possible  5  per 
cent,  or  10  per  cent,  to  the  life  of  his  A  battery? 
It  is  to  laugh. 

The  number  of  hours  the  average  set  is  used 
daily  is  a  moot  question.  At  one  time,  it  was 
generally  felt  that  two  hours  a  day  was  fairly 
representative  of  average  performance.  But 
of  late,  loud  speakers  are  coming  into  more 
general  use,  and  because  of  this,  the  amount 
of  time  put  in  by  the  average  set  has  gone  up 
considerably.  Eventually,  of  course,  all  re- 
ceiving sets  will  employ  loud  speakers.  A 
receiving  set  without  a  loud  speaker  will  some 
day  be  as  much  of  a  curiosity  and  excite  as 
much  comment  as  an  automobile  without  a 
top.  Because  of  the  tendency  toward  universal 
loud-speaker  operation,  it  is  felt  that  the  time 
the  average  set  is  used  daily  is  closer  to  four 
hours  than  two.  There  are  some  individual 
cases  known  where  the  set  is  used  an  average 
of  eight  hours  a  day! 

The  most  economical  current  drain  on  the 
dry  cells  used  as  an  A  battery  can  be  obtained 
by  connecting  the  proper  number  of  cells  in 
multiple.  When  this  is  done,  the  total  drain  is 
equally  divided  between  the  cells,  so  that  each 
one  delivers  only  a  fraction  of  the  total.  In 

TO  RECEIVING  SET 

_U  f  b  


FIG.  3 

From  sets  employing  four  or  five  tubes,  maximum 
economy  will  be  obtained  by  using  six  dry  cells,  connected 
three  in  series  and  two  in  multiple,  as  shown  here.  When 
flashlight  cells  are  used,  this  last  arrangement  forms  the 
most  economical  A  battery  for  one  tube 


connection  with  UV-199's,  however,  the  situa- 
tion is  somewhat  complicated,  because  of  the 
necessity  of  using  three  cells  connected  in 
series  to  obtain  the  correct  voltage.  This  is 
not  so  bad  as  it  appears,  for  it  is  only  necessary 
to  consider  three  cells  connected  in  series  as  a 
battery.  Then  any  number  of  such  three-cell 
batteries  may  be  connected  in  multiple  to  get 
the  most  economical  drain  on  each. 

The  curves  (Fig.  1)  will  be  useful  in  determin- 
ing the  most  economical  battery  for  any  given 
radio  set.  As  an  example,  assume  a  set  having 
three  UV-199  tubes.  The  total  drain  there- 
fore is  3  x  .060  =  .180  amperes.  Reference  to 
Fig.  1  shows  that  the  corresponding  capacity 
is  23  ampere-hours  when  used  two  hours  per 
day.  If  the  drain  is  reduced  by  using  two 
three-cell  batteries  connected  in  multiple,  the 
total  drain  of  .180  amperes  is  equally  divided 
between  the  two  batteries,  so  that  the  drain 
on  each  is  only  .090  amperes.  But  at  this 
drain,  the  capacity  of  each  battery  is  only  22 
ampere-hours,  which  is  less  than  when  the  drain 
is  .180  amperes.  Therefore,  for  sets  employing 
one  to  three  UV-199  tubes,  the  most  economical 
"A"  battery  is  one  made  up  of  three  six-inch 
dry  cells,  connected  in  series  (Fig.  2). 

Now,  take  the  case  of  a  four-tube  set.  Here 
the  total  drain  is  .240  amperes,  and  the  corres- 
ponding capacity  is  19  ampere-hours.  By 
using  two  three-cell  batteries  connected  in 
multiple  the  drain  on  each  is  reduced  to  .120 
amperes,  with  a  corresponding  capacity  of  26 
ampere-hours  for  each  battery,  or  a  combined 
capacity  of  52  ampere-hours.  This  is  by  far 
the  most  economical  battery  to  use,  for  while 
it  requires  double  the  number  of  cells,  the 
amount  of  service  is  considerably  more  than 
doubled. 

Applying  the  same  method  of  calculation  to 
different  numbers  of  UV-199  tubes,  the  most 
economical  battery  is  found  to  be  as  follows: 

For  one  to  three  tubes,  use  three  cells  con- 
nected in  series  (Fig.  2). 

For  four  or  five  tubes,  use  two  three-cell 
batteries  connected  in  multiple  (Fig.  3). 

For  six  or  more  tubes,  use  three  three-cell 
batteries  connected  in  multiple  (Fig.  4). 

Because  of  its  ability  to  operate  from  an  A 
battery  made  up  of  flashlight  cells,  the  UV-199 
lends  itself  admirably  to  the  construction  of 
small  portable  sets.  Such  a  battery  is  much 
smaller  and  lighter  than  a  six-inch  dry  cell, 
and,  taking  advantage  of  these  properties,  it  is 
possible  to  design  a  complete  receiving  set, 


What  Radio  Holds  for  Boy  Scouts 


251 


including  all  the  necessary  batteries  in  a  re- 
markably small  amount  of  space.  It  should  be 
remembered,  however,  that  electrical  energy 
in  the  form  of  flashlight  cells  is  somewhat  more 
expensive  than  in  six-inch  dry  cells.  There 
fore,  when  designing  a  portable  set,  it  is  ad- 
visable to  provide  terminals  to  which  an  ex- 
ternal A  battery  of  six-inch  dry  cells  may  be 
connected.  Then,  when  the  set  is  to  be  used 
at  home,  use  the  large  battery,  and  depend  on 
flashlight  batteries  only  when  the  set  is  to  be 
taken  away  on  a  trip. 

Only  the  largest  size  flashlight  cells,  which 
are  approximately  2 J  in.  long  and  if  in.  in 
diamater,  should  be  used.  They  take  up  very 
little  more  room  than  the  smaller  sizes,  but 
they  last  a  great  deal  longer. 

The  current  drain  which  gives  maximum 
capacity  for  the  large  size  flashlight  cell  is  .030 
ampere.  This  is  one  half  the  drain  caused  by 
one  UV-199  tube,  therefore,  the  most  econo- 
mical [flashlight  A  battery  is  one  using 'six 
cells  for  each  tube,  connected  as  in  Fig.  3. 
However,  a  single  three-cell  battery  will  give 
remarkable  results,  considering  its  size.  When 
used  between  one  and  two  hours  per  day,  such 
a  battery  of  reliable  manufacture  will  give 
approximately  30  hours  of  service,  which  is 
sufficient  for  most  vacation  trips. 

Never  attempt  to  operate  more  than  one 
UV-199  tube  from  a  battery  of  three  flashlight 
cells.  Use  at  least  as  many  such  batteries  as 
there  are  tubes  in  the  set,  otherwise  the  current 
drain  on  the  cells  will  be  so  heavy  that  the 
amount  of  service  obtainable  from  them  will  be 
seriously  reduced. 


TO  RECEIVING  SET 


FIG.  4 

When  six  or  more  UV-199's  are  used,  it  is  best  to 
employ  nine  dry  cells  connected  as  shown  above 


In  planning  the  construction  of  a  small 
portable  set,  the  designer  will  naturally  util- 
ize the  smallest  size  B  battery,  to  conserve 
space  and  cut  down  weight.  But  for  home  use, 
it  is  inadvisable  to  depend  on  these  tiny  bat- 
teries, primarily  because  their  capacity  is 
extremely  limited.  Provision  should  be  made 
for  connecting  a  large  external  B  battery  to 
the  set,  just  as  in  the  case  of  the  A  battery. 
The  large  size  B  battery  has  many  times  the 
capacity  of  the  small  one,  but  costs  less  than 
twice  as  much. 


What  Radio  Holds  for  Boy  Scouts 

A  Brief  Outline  of  Some  of  the  More  Important  Possibilities  of  Radio  in  Their 
Application  to  One  of  the  Biggest  and  Best  Games  America  has  Ever  Gone  in  For 

By  ARTHUR  H.  LYNCH 


A  S  MOST  of  us  know,  the  Boy  Scout 
/\      is  pledged  to  "  Do  a   good  turn 
L  \     daily."    Let   us    consider  briefly 
/     %    some  of  the  aspects  of  radio  as  they 
may  be  applied  to  Scouting  to  make 
it  possible  for  a  number  of  good  turns  to  be 
done.    One  of  the  best  troop  activities  I  know 
of  is  the  building  of  complete  receiving  sets 
by  troops  for  installation  in  hospitals.  Scout 


leaders  throughout  the  country  should  ap- 
preciate some  of  the  direct  benefits  which  will 
come  to  their  troop  following  a  campaign  of  this 
sort.  First  of  all,  it  will  indicate  quite  clearly 
to  the  citizens  of  the  community  that  the  par- 
ticular Scout  troop  engaged  in  this  work  is 
not  only  interested  in  its  own  welfare  but  in 
the  welfare  of  the  community.  And  what 
better  activity  could  any  of  us  engage  in  than 


252 


Radio  Broadcast 


doing  our  small  part  to  make  life  more  pleasant 
for  those  in  hospitals? 

In  order  to  put  a  radio  set  in  a  hospital  sat- 
isfactorily, it  is  generally  necessary  to  arrange 
for  two  types  of  reception.  As  a  rule  a  com- 
plete receiving  set  provided  with  suitable 
amplifiers  is  all  that  is  necessary.  If  this  outfit 
is  of  the  loop  variety,  it  may  be  mounted  on  a 
"tea-wagon"  and  wheeled  about  from  one 
room  to  another  without  difficulty.  If  it  is 
taken  into  a  convalescent  ward  it  is  unlikely 
that  a  loud  speaker  would  prove  disturbing 
to  any  of  the  patients,  but  in  those  rooms  or 
wards  where  the  patients  are  very  sick,  a  better 
arrangement  is  to  have  a  telephone  receiver  or 
pair  of  receivers  attached  to  a  plug  and  placed 
beside  each  bed.  In  this  instance,  the  tuning 
equipment  would  be  controlled  by  a  hospital 
attendant  and  the  incoming  signals  would  be 
sent  through  the  hospital  on  a  set  of  wires  with 
plugs  at  each  bed.  Patients  who  desired  to 
listen-in  would  then  only  have  to  place  the 
plug  attached  to  their  telephones  in  the  socket 


to  hear  whatever  was  going  on,  without  an- 
noying their  neighbors  in  any  way. 

In  a  community  of  any  size  it  should  not  be 
difficult  for  an  active  Scout  troop  to  secure  an 
appropriation  large  enough  to  pay  for  the  wiring 
if  the  troop  itself  would  undertake  to  furnish 
the  radio  equipment,  and  it  is  likely  that  those 
who  enjoy  this  broadcasting  brought  to  them 
by  the  Scout  troop  will  look  with  favor  upon 
other  activities  that  this  particular  troop 
undertakes. 

IN  THE  CONTAGIOUS  SICK  ROOM 

ANOTHER  very  important  work  that  lends 
itself  particularly  to  Scouting  is  the  instal- 
lation of  receiving  outfits  in  the  homes  of  people 
who  are  quarantined  because  of  contagious 
diseases.  Scarlet  fever,  for  example,  is  some- 
times followed  by  serious  complications,  and 
in  order  to  ward  off  complications  of  this 
nature  it  may  be  necessary  for  the  patient  to 
be  kept  in  a  dark,  or  partly  dark,  room.  In 
order  that  the  eyes  may  not  be  strained,  reading 


— ■•'  -  r~  """" 


CONVALESCING  HOSPITAL  PATIENTS  FIND  RADIO  A  GREAT  BOON 
It  helps  to  pass  pleasantly  the  time  they  must  lie  in  bed  or  stay  indoors.  A  whole  troop  of  scouts  should  have  little  dif- 
ficulty in  earning  enough  to  pay  for  the  installation  and  up-keep  of  a  set  such  as  this  in  the  hospital  in  their  community 


What  Radio  Holds  for  Boy  Scouts 


253 


is  not  allowed  and  where  a 
contagious  disease  exists, 
the  patient  is  not  even  al- 
lowed the  privilege  of  an 
occasional  visit  from  his 
friends.  Naturally,  a  person 
who  is  ordinarily  active  and 
in  touch  with  the  affairs  in 
the  world,  when  confined  to 
bed  under  conditions  of  this 
sort  finds  the  rest  particu- 
larly irksome.  A  radio  set, 
in  such  a  case,  will  undoubt- 
edly win  for  the  Scout  or 
Scout  troop  that  installs  it 
the  everlasting  apprecia- 
tion of  the  patient. 

In  making  an  installation  of  this  character 
however,  every  precaution  should  be  taken  to 
safeguard  oneself  against  the  possible  contrac- 
tion of  the  disease,  and  it  is  not  advisable  for 
those  who  supply  the  equipment  to  make  the 
installation  personally  because  it  would  be 
possible  to  carry  the  disease  to  others  even 
though  they  did  not  contract  it  themselves.  It 
is  always  better  to  make  an  installation  of  this 
character  in  strict  accordance  with  the  dictates 
of  the  local  Board  of  Health.  For  example, 
a  set  might  best  be  assembled  out  of  the  sick 
room,  and  its  operation  explained  to  someone 
in  charge  of  the  patient. 

in  veterans'  hospitals 

MOST  of  us  hear  very  little  to-day  of  those 
war  veterans  who  are  patients  in  hos- 
pitals maintained  by  the  Government,  but  there 
are  a  great  many  of  them.  Would  it  not  be 
well  for  the  Scouts  of  the  country  to  undertake 
a  campaign  to  secure  radio  outfits  for  these 
men?  In  many  instances  some  of  those  in  the 
hospitals  are  quite  familiar  with  radio  receiving 
equipment  and  would  be  able  to  install  and 
operate  outfits  if  they  had  them.  In  this  way 
they  would  be  able  to  bring  entertainment  to 
the  fellows  who  are  still  confined  to  their  cots. 

A  great  many  radio  sets  have  been  bought  that 
are  not  at  present  being  used.  Many  people 
who  purchased  crystal  outfits  have  gradually 
put  them  aside  in  favor  of  tube  sets.  These 
crystal  outfits  are  performing  the  rather  useless 
function  of  collecting  dust  in  attics  or  closets. 
The  number  of  broadcasting  stations  in  the 
country  has  increased  so  rapidly  that  very  few 
veterans'  hospitals  are  now  out  of  range  of  all 
stations,  with  a  crystal  receiver.  Receiving 


SCOUTS  LEARN  TO  MAKE  THINGS  WITH  THEIR  HANDS 
An  up-and-doing  crowd  of  boys  such  as  this  could  do  a  good  turn, 
size  extra  large,  by  combining  to  build  radio  receivers  for  invalids 


outfits  would  be  particularly  appreciated  at 
this  time  of  year  when  most  of  the  stations  in 
the  country  are  broadcasting  the  baseball 
scores.  Most  of  these  men  are  baseball  fans 
and  follow  the  game  as  closely  as  they  can.  One 
of  the  best  ways  to  help  put  some  fun  and  diver- 
sion into  the  lives  of  these  fellows  is  to  get  them 
to  think  about  baseball.  A  radio  set  will  help 
them  to  do  it. 


1  co 


IN  SCOUT  CAMPS 

[ERE  are  many  Scout  camps  in  this 
country  at  present,  and  it  is  more  than 
likely  that  the  majority  of  these  camps  will 
have  at  least  one  good  radio  outfit  this 
summer.  The  large  set  may  be  used  in  the 
evening  to  entertain  the  gang  and  the  various 
small  sets  may  be  used  in  field  communication 
activities.  Simple  low-powered  telephone  and 
telegraph  transmitters  will  make  the  signaling 
course  particularly  attractive  this  summer.  A 
good  transmitting  station  at  camp  headquarters 
will  serve  to  transmit  all  kinds  of  messages  to 
troops  in  the  field,  and  maneuvers  may  be 
engaged  in  that  would  be  entirely  impossible 
otherwise.  Radio  as  a  means  of  signaling  is 
very  much  superior  to  wigwagging  or  even 
wire  telegraphy;  and  another — and  perhaps  the 
best — application  of  radio  in  camp  is  a  course 
in  the  building  of  receiving  equipment  under 
the  guidance  of  a  Scoutmaster  who  is  thor- 
oughly capable  of  carrying  on  this  work.  For 
instance,  it  is  well  for  a  camp  to  offer  as  part 
of  its  curriculum,  a  course  in  simple  receiver 
design.  The  experience  the  boys  get  in  build- 
ing their  own  receivers  is  not  only  helpful  to 
them  in  securing  a  knowledge  of  radio  but  it 
gives  them  an  intimate  knowledge  of  wood- 


254 


Radio  Broadcast 


working,  soldering  and  the  use  of  various 
tools. 

That  the  boys  of  this  country  are  interested 
in  this  sort  of  work  is  very  apparent  from  the 
fact  that  in  a  single  camp  last  year  seventy-six 
per  cent,  of  the  boys  who  attended  constructed 


radio  receiving  sets— and  the  fun  didn't  end 
with  the  boys:  it  gave  them  something  with 
which  to  entertain  the  whole  family. 

Radio  really  has  something  to  offer  Scouting. 
Let  all  Scouts  make  the  best  of  it  this  sum- 
mer. 


Radio  Broadcast  Central 

The  Radio  Corporation's  Station  at  Aeolian  Hall,  New  York  — The  Dream  of  the  Pioneer  of 
1903,  the  Vision  of  the  Engineer  of  1913,  a  Reality  for  the  Betterment  of  Mankind  in  1923 

By  PIERRE  BOUCHERON 

Director  of  Advertising  and  Publicity  of  the  Radio  Corporation  of  America 


A  MID  the  hustle  and  bustle  of  the 
/%      world's  greatest  metropolis,  a  new 
/jk     broadcasting  station  has  been  estab- 
J      %    lished.     It  is  different   from  any 
^  station  we  have  seen,  so  far,  in 
that  it  is  made  up  of  a  quadruple  personality, 
so  to  speak.    Except  for  the  fact  that  it  em- 
ploys but  two  antennas,  it  incorporates  four 
complete  broadcasting  stations.    There  are, 


WHEN  A  TUBE  BLOWS 


It  is  necessary  for  the  operator  in  the  operating  room  on  the  roof  merely  to  cut 
out  the  transmitter  thus  crippled  and  switch  in  another.  There  are  two  separate 
broadcasting  "  channels,"  one  for  WJZ  and  one  for  WJY,  and  each  channel  is 
equipped  with  two  transmitters.  Besides  the  operating  crew,  there  is  a  man 
constantly  listening-in  for  vessels  in  distress.  If  he  hears  an  SOS,  the  broad- 
casting is  immediately  suspended 


to  be  sure,  only  two  studios,  but  in  these  days  of 
out-of-the-studio  broadcasting,  two  are  quite 
sufficient,  and  the  arrangements  for  this  sort 
of  broadcasting  made  at  Radio  Broadcast  Cen- 
tral are  in  keeping  with  the  great  advance 
marked  by  the  station  itself. 

For  instance,  a  permanent  group  of  wire 
lines  has  been  run  along  Sixth  Avenue  for 
several  miles,  beginning  at  14th  Street.  There 
are  permanent  lines  from 
this  central  cable  to  the 
Town  Hall,  the  Waldorf 
Astoria  Hotel  and  Aeolian 
Hall.  By  running  short, 
temporary  lines  to  theatres 
or  other  important  gather- 
ing places,  it  is  possible  to 
supply  the  radio  audience 
with  the  best  of  music, 
drama,  humor,  lectures,  re- 
ligious services,  and  the  like 
that  New  York  can  furnish. 
In  opening  Radio  Broadcast 
Central,  Mr.  Owen  D. 
Young,  Chairman  of  the 
Board  of  the  Radio  Cor- 
poration of  America, 
summed  up  this  phase  of 
the  enterprise  in  the  follow- 
ing words: 

"Broadcasting  has  ap- 
pealed to  the  imagination 
as  no  other  scientific  de- 
velopment of  the  time.  Its 
ultimate  effect  upon  the 
educational,  social,  politi- 
cal, and  religious  life  of  our 


Radio  Broadcast  Central 


255 


country  and  of  the  world  is 
quite  beyond  our  ability  to 
prophesy. 

"Already  it  is  bringing  to 
the  farmer,  market,  weather, 
and  crop  reports  as  well  as 
time  signals,  which  cannot 
help  but  be  of  economic 
value:  in  remote  communi- 
ties, where  the  country  par- 
son is  no  longer  in  attend- 
ance at  Sunday  morning 
services,  it  is  filling  a  great 
need  in  the  spiritual  life;  its 
educational  possibilities  are 
being  investigated  by  our 
foremost  national  and  state 
educators;  it  is  taking  en- 
tertainment from  large 
centres  to  individual 
homes;  to  the  blind  and 
sick  it  has  unfolded  a  new 
and  richer  life.  For  the 
purpose  of  communication 
it  has  destroyed  time  and 
space." 

There  are  two  stations 
at  Radio  Broadcast  Central, 
which  may  be  operated  sim- 
ultaneously or  individually. 
WJZ  is  the  455-meter  sta- 
tion, used  to  broadcast 
music  and  entertainment  of 
the  lighter  kind,  while  WJ  Y, 
operated  on  405  meters,  is 
used  for  broadcasting  opera, 
classical  music,  and  lectures 
on  more  serious  subjects. 

At  Aeolian  Hall,  where  this  super-station  is 
located,  WJZ  and  WJY  are  characterized  as 
channels  A  and  B  respectively,  and  each  is 
equipped  with  two  complete  sets  of  equipment 
in  order  to  prevent  any  break  in  the  program 
being  broadcasted,  regardless  of  any  mechan- 
ical trouble  that  may  develop.  There  are 
two  pick-up  devices  in  each  studio,  as  well  as  a 
system  of  dual  wiring  from  the  studio  to  the 
control  station  on  the  roof  where  two  complete 
transmitters  are  used  on  each  channel. 


AEOLIAN  HALL,  NEW  YORK 
From  40th  Street,  with  the  Public  Library  in  the  Foreground 


The  broadcasting  from  Aeolian  Hall  is 
already  recognized  as  being  of  the  highest 
character.  In  dedicating  the  station  to  the 
people  of  America,  General  Harbord,  President 
of  the  Radio  Corporation,  said:  "This  station 
will  gather  from  every  part  of  New  York  City 
and  from  all  available  sources  all  that  will 
instruct  and  entertain,  and  hurl  it  over  millions 
of  square  miles  of  territory."  It  is,  as  the 
General  expressed  it,  "  the  world's  first. national 
theatre." 


The  Grid 


QUESTIONS  AND  ANSWERS 

The  Grid  is  a  Question  and  Answer  Department  maintained  especially  for  the  radio  amateurs.  Full 
answers  will  be  given  wherever  possible.  In  answering  questions,  those  of  a  like  nature  will  be  grouped 
together  and  answered  by  one  article.  Every  effort  will  be  made  to  keep  the  answers  simple  and  direct, 
yet  fully  self-explanatory.  Questions  should  be  addressed  to  Editor,  "  The  Grid,"  Radio  Broadcast, 
Garden  City,  N.  Y. 


AUDIO  AMPLIFYING  CIRCUITS 

/  have  a  two-step  receiver  of  my  own  const r  ction,  using 
Cunningham  detector  and  two  Cunningham  amplifiers. 

This  arrangement  is  not  giving  satisfaction,  and  I  should 
appreciate  your  publishing  what  you  consider  to  be  the  best 
amplifying  hook-up. 

— E.  E.  B.,  Itta  Bene,  Miss. 

AUDIO-FREQUENCY  amplification  has  become  so 
standardized  that  the  various  transformer  coupled 
k>  hook-ups  have  resolved  themselves  into  a  single- 
conventional  circuit,  which  may  be  applied  to  any  receiv- 
ing set.  This  fact  is  at  variance  with  the  impression  under 
which  many  of  our  readers  labor,  that  different  receiving 
circuits  require  different  systems  of  audio-frequency  am- 
plification. 

Figure  I  shows  the  usual  circuit  for  a  two-step  ampli- 
fier. The  three  telephone  jacks  make  it  possible  to  plug 
in  at  the  detector,  first  or  second  stage.  The  last  jack 
(J2)  may  be  an  open-circuit  jack,  as  in  the  diagram,  or  a 
closed-circuit  one  simliar  to  Jd  and  Ji,  the  inner  contacts 
running  to  binding  posts  for  a  loud-speaker.  Thus,  when 
the  plug  is  removed  (the  headset  eliminated)  the  loud- 
speaker is  automatically  thrown  into  the  circuit. 

No  amplifier  will  operate  properly  on  poor  tubes  or 
transformers,  nor  will  satisfactory  amplification  be  secured 
on  a  plate  voltage  under  sixty.  The  bulb  should  be  a  hard 
one,  i.  e.,  there  should  be  no  blue  or  purple  haze  about  the 
elements  when  the  plate  voltage  is  applied  and  the  filament 
lighted.  The  amplifying  transformers  should  be  of  a 
reliable  manufacture,  and  the  experimenter  is  advised 
to  expend  from  four  to  seven  dollars  in  procuring  them, 
rather  than  purchase  transformers  of  doubtful  value  for 
half  that  price. 

The  transformers  should  be  mounted  with  at  least  four 


inches  between  cores,  and  many  experimenters  make  a 
practice  of  placing  the  transformers  with  the  cores  at  right 
angles  to  each  other.  Careful  separating  of  instruments 
and  wiring  in  amplifying  circuits  eliminates  feed-back  with 
resulting  howls  and  squeals. 

Rheostats  of  the  wire  or  compression  types,  vernier  or 
otherwise,  may  be  used.  The  1^  volt  tubes  are  also  adapt- 
able to  amplification  circuits,  and  will  give  very  good  re- 
sults when  used  in  con  junction  with  transformers  designed 
to  balance  their  impedance. 

The  only  restrictions  on  panel  layout  are  those  con- 
current with  adequate  spacing,  and  the  experimenter 
may  build  the  amplifier  so  that  it  will  conform  in  appear- 
ance with  his  present  apparatus.  However,  before  con- 
structing the  set,  it  is  suggested  that  the  builder  familiarize 
himself  with  the  interior  details  of  some  standard  manu- 
factured amplifier. 

Connections  should  be  well  soldered,  using  soldering 
paste  rather  than  acid  or  rosin,  and  all  superfluous  flux 
should  be  wiped  away,  washing  the  joints  if  necessary 
with  wood  alcohol.  This  precaution  is  particularly  im- 
portant on  the  lugs  of  the  jacks,  where  messy  soldering  will 
result  in  annoying  clicks  and  extraneous  sounds. 

Such  an  amplifying  installation  (Fig.  1)  may  be  added  to 
any  receiving  set  by  disconnecting  the  telephone  receivers,  and 
replacing  them  by  the  primary  of  the  first  stage,  amplifying 
transformer  {input).  Condenser  C,  indicated  in  the  dia- 
gram, is  a  telephone  shunt  condenser  of  .002  mfd.  capac- 
ity. It  is  possible  that  such  a  condenser  is  already  in- 
cluded in  the  experimenter's  present  receiving  equipment, 
in  which  case  the  extra  capacity  will  not  be  necessary. 

MULTI-LAYER    COILS   AND  INDUCTION 

Can  you  tell  me  what  si^e  honeycomb  DL  coils,  according 
to  catalogue  numbers,  are  best  for  receiving  broadcasts  on  360 


T0+  OF  DETECTOR 

"B"  BAT.  ~ 

FIG.  I 

The  usual  circuit  for  a  two-step  amplifier.  The  lead  from  the  second  amplifier  rheostat  should,  of  course,  go  to  "+  A' 


RADIO  BROADCAST  ADVERTISER 


Get  Long  Range 

with  RCA  radio- 
frequency  transformers 


Model  UV-1714 
$6.50 


Model  UV-1716 
$8.50 


—To  make  a  small  inside 
loop  reach  as  far  as  an  out- 
side antenna. 

— To  increase  tremendously 
the  range  of  an  outdoor 
aerial  without  distortion. 

—To  amplify  singly  or  in  cas- 
cade; complete  shielding 
prevents  interaction  of 
fields. 

— To  cover  a  broad  band  of 
wave  lengths  and  pick  up 
stations  of  every  class. 

Particularly  Adapted  for  Use 
with  RCA  Radiotron  Tubes 


Insist  on  RCA  audio  and  radio-frequency 
transformers  at  your  dealer 


This  symbol  of  quality 
is  your  protection 


Corporation 

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Sales  Dept.,  Suite  2066 
233  Broadway 
New  York,  N.  Y. 


District  Sales  Offices 
10  South  LaSalle  Street,  Chicago,  III. 
433  California  Street,  San  Francisco,  Cal. 


•jf  Tested  and  approved  by  Radio  Broadcast  -jc 


258 


Radio  Broadcast 


l|l|l|l|l|l|l|H 

22jV. 


FIG.  2 

The  "Flivver"  Circuit 

and  400  meters,  i.  e.,  the  si\ei  to  use  in  primary,  secondary, 
and  tickler?    What  do  the  numbers  mean? 

1  would  also  like  to  know  what  causes  the  humming  noise 
in  my  receivers  when  I  am  using  two  steps  of  audto-frequency 
amplification.  It  sounds  like  a  generator  hum,  and  it  is 
present  over  the  entire  tuning  range  of  the  set. 

L.  T.,  Cincinnati,  Ohio. 

THE  DL35,  DL50,  and  DL75  are  the  correct  sizes  for 
broadcast  reception,  primary,  secondary,  and  tickler 
being  respectively  indicated. 
On  the  original  honeycomb  coils,  the  numerals  referred 
to  the  number  of  turns  of  wire  wound  on  thex  designated 
coil.  Thus,  an  L50  was  wound  with  fifty  turns  of  wire. 
However,  a  slightly  different  method  of  winding  was  shortly 
discovered,  which  resulted  in  coils  superior  to  the  original 
honeycombs;  and  it  was  found  that  the  number  of  turns 
on  the  new  coils,  called  the  Duolateral  or  DL,  neces- 
sary to  secure  a  certain  value  of  inductance,  differed 
from  the  number  of  turns  required  by  the  honeycomb 
for  the  same  effect.  The  numeral  following  the  intials 
"  DL"  indicates  that  the  duolateral  coil  may  be  substituted 
for  a  honeycomb  coil  of  that  number  of  turns. 

The  humming  heard  in  the  telephone  receivers  is  prob- 
ably due  to  induction  from  near-by  electric  light  wires.  A 
reading  lamp  on  the  operating  table  is  often  sufficient  to 
give  rise  to  such  a  disturbance,  and  usually  the  trouble  can 
be  remedied  by  merely  moving  the  lamp  farther  from  the 
instruments,  particularly  from  the  detector  and  amplifying 
cabinet.  If  ordinary  care  is  taken  to  keep  unnecessary 
electric  light  wires  away  from  the  apparatus,  and  to  run 
those  essential  to  its  operation  in  armored  cable,  the  hum 
will  be  eliminated. 

However,  if  our  correspondent  is  using  a  single-circuit 
tuner,  it  is  possible  that  the  sound  is  induced  from  the  street 
lines  to  his  antenna. If  such  is  the  case,  an  inductively 
coupled  tuner  will  rectify  matters. 

Farm  Lighting  Plants  and  Radio 

/  am  located  on  a  farm  which  is  equipped  with  a  32-volt 
lighting  plant.  Can  this  be  used  in  any  way  for  radio  re- 
ception? B.  O.  Z„  Bouck's  Falls,  N.  Y. 

A FARM  lighting  plant  can  be  used  very  nicely  for 
the  lighting  of  receiving  filaments,  it  being  only 
necessary  to  include  sufficient  resistance  in  the 
circuit  to  drop  the  voltage  and  protect  the  tubes. 


A  series  of  6-  or  10-ohm  porcelain-base  rheostats  is  a 
convenient  resistance  for  this  purpose.  Using  a  single 
tube  drawing  one  ampere,  such  as  the  UV-200  and  UV-201, 
a  variable  resistance  with  a  maximum  of  30  ohms  will  be 
sufficient  to  drop  the  32  volts  to  the  working  potential  of 
the  bulb.  However,  if  the  WD-11,  201-A  or  a  similar 
quarter-ampere  tube  is  used,  the  resistance  must  be  con- 
siderably higher,  using  not  less  than  125  ohms  for  a  single 
bulb. 

If  two  tubes  are  to  be  used  constantly,  the  external  re- 
sistance may  be  halved,  and  if  three  tubes,  it  may  be 
lowered  two  thirds  the  total  resistance  given  for  a  single 
tube.  This  is  due  to  the  fact  that  the  voltage  drop  is 
directly  proportional  to  the  current  consumed.  Therefore, 
all  tubes  must  be  turned  off  by  a  common  switch,  and  the 
circuit  through  amplifying  filaments  never  broken  until 
the  resistance  is  increased  to  the  required  value  for  the 
remaining  detector  bulb. 

In  all  cases  where  bulbs  are  lighted  from  a  comparatively 
high  voltage  dropped  through  a  common  resistance,  each 
tube  should  be  separately  fused,  in  order  to  protect  the 
remaining  bulbs  when  the  filament  of  one  burns  out  in  the 
course  of  time.  Unless  this  precaution  is  taken,  the  sound 
tubes  will  necessarily  be  blown  in  the  sudden  rise  of  the 
applied  voltage. 

In  some  types  of  farm  lighting  equipment  one  side  of  the 
line  will  be  found  grounded.  While  this  will  not  affect 
reception  with  certain  receivers,  on  the  majority  of  circuits 
it  will  result  in  undesirable  complications  and  probably 
decrease  selectivity.  When  this  ground  is  not  effected 
through  the  frame  of  the  engine  and  the  exhaust  pipe,  it  is 
easily  eliminated  by  removing  the  ground  wire. 

The  "  Flivver  Set" 

Will  you  please  give  me  the  circuit  of  the  so-called  "  Flivver 
Set"?  I  am  anxious  to  construct  this  apparatus  which  I 
understand  is  a  very  simple  and  excellent  regenerative  receiver. 

The  required  parts  are,  I  believe,  43-plate  condenser  {vari- 
able), 1  Duolateral  coil  of  fifty  turns,  detector  tube,  dc. 

R.  W.  W.,  Wilkes  Barre,  Pa. 

THE  accompanying  diagram  (Fig.  2)  indicates  the 
connections  for  the  "Flivver  Set."  The  single  tube 
"super"  is  also  called  the  "flivver." 
However,  Radio  Broadcast  does  not  recommend  the 
use  of  this  circuit  in  its  unmodified  form  in  other  than 
isolated  radio  districts.  The  flivver  system,  which  oscil- 
lates almost  continually  during  the  process  of  tuning,  is 
nothing  more  than  the  Colpitts  transmitting  circuit  used 
extensively  in  continuous-wave  transmission.  Even  when 
employed  as  a  receiver,  with  a  soft  tube  and  low  plate 
voltage,  it  is  capable  of  radiating  an  interfering  wave 
which  may  be  often  picked  up  with  annoying  consequences 
over  a  mile  away.  Out  of  consideration  for  other  listeners 
this  circuit,  as  shown,  should  never  be  used  in  cities  or 
even  small  towns. 

However,  in  such  congested  localities,  the  undesirable 
radiation  may  be  eliminated  by  the  addition  of  one  step 
of  tuned-plate  radio-frequency  amplification.  There  are 
several  excellent  sets,  using  this  system,  on  the  market. 
However,  when  this  pound  of  cure  is  resorted  to,  the  total 
expense  of  the  apparatus,  which  is  now  a  two-bulb  set,  and 
the  comp'exity  of  the  installation  are  such  that  the  original 
purchase  or  building  of  a  selective  three-circuit  tuner  is 
recommended  as  preferable. 


RADIO  BROADCAST  ADVERTISER 


1  ill  f*H 

I  ^ 

!r  f  1 

i  1  :  •  ■;  .  ; 

I :     | ]  i  '<, 
(■_._  IM  -j 

Magnavox  keeps  the  "stay-at-homes"  happy 


THE  "boys"  just  naturally  make  their  headquarters 
in  proximity  to  the  receiving  set  whose  owner  has 
been  wise  enough  to  add  a  Magnavox  Reproducer  and 
Power  Amplifier.  When  "Magnavox  invites  you."  the 
Radio  party  is  sure  to  be  a  success. 

Magnavox  R2  Reproducer  and  2  stage    Model  C  Magnavox  Power  Amplifier 


Power  Amplifier  (as  illustrated)  $115.00 

R2  Magnavox  Reproducer  with  18-inch 
horn:  the  utmost  in  amplifying  power; 
requires  only  .6  of  an  ampere  for  the 
field  $60.00 

R3  Magnavox  Reproducer  with  14-inch 
curvex  horn:  ideal  for  homes,  offices, 
etc  $35.00 


insures  getting  the  largest  possible  power 
input  for  your  Magnavox  Reproducer 

2  stage  $55.00 

3  stage  75.00 
Magnavox  Products  can  be  had  from  good 
dealers  everywhere.  Write  for  new  booklet. 

THE  MAGNAVOX  COMPANY 

Oakland,  California 
New  York  Office:  370  Seventh  Avenue 


7-R 


Magnavox  Products 

No  Radio  Receiving  Set  is  complete  without  them 


■jt  Tested  and  approved  by  Radio  Broadcast  -fa 


Supplemental  List  of  Broadcasting  Stations  in  the  United  States 

LICENSED  FROM  APRIL  21  TO  MAY  17  INCLUSIVE 


CALL 
SIGNAL 


FREQUENCY 

(Kilocycles) 


WAVE- 
LENGTH 


KFEX  Augsburg  Seminary,  Minneapolis,  Minn   1 1 50  261 

KFGC  Louisiana  State  University,  Baton  Rouge,  La   1180  254 

KFGJ  138th  Inf.,  National  Guards,  St.  Louis,  Mo   1130  266 

KFGM  Abilene  Daily  Reporter,  Abilene,  Texas   1290  233 

KFGP  Cheney  Radio  Co.,  Cheney,  Kans   13 10  229 

KFGQ  Crary  Hardware  Co.,  Boone,.  Iowa   1330  226 

KFGV  Heidbreder  Radio  Supply  Co.,  Utica,  Nebr   1340  224 

KFGX  First  Presbyterian  Church,  Orange,  Tex   1200  250 

KFGY  Gjelhaug's  Radio  Shop,  Baudette,  Minn   1340  224 

KFGZ  Emmanuel  Missionary  College,  Berrien  Springs,  Mich   1120  268 

KFFX  The  McGraw  Co.,-  Omaha,  Nebr   1080  278 

KFHC  University  of  Oklahoma,  Norman,  Okla   1180  254 

KFHD  Utz  Electric  Co.,  St.  Joseph,  Mo   1330  226 

KFHF  Central  Christian  Church,  Shreveport,  La  ■   1 130  266 

KFHI  Chas.  V.  Dixon,  Wichita,  Kans   1340    s  224 

KFHL  Penn  College,  Oskaloosa,  Iowa   1320  ':  227 

KFIB  Franklin  W.  Jenkins,  St.  Louis,  Mo.  .     :   1230  244 

KFIC  Philip  Laskowitz,  Denver,  Colo   134°  224 

KFID  Ross  Arbuckle's  Garage,  Iola,  Kans   1220  246 

KFIQ  Yakima  Valley  Radio  Broadcasting  Assn.,  Yakima,  Wash  .    ,  1240  224 

WABC  Fulwider-Grimes  Battery  Co.,  Anderson,  Ind.     1310  229 

WABD  Parker  High  School,  Dayton,  Ohio  .'  .  .    1   1060  283 

WABE  Y.  M.  C.  A.,  Washington,  D.  C   1060  283 

WABF  Mt.  Vernon  Register-News  Co.,  Mt.  Vernon,  111   1280  234 

WABG  Arnold  Edwards  Piano  Co.,  Jacksonville,  Fla   1210  248 

WABH  Lake  Shore  Tire  Co.,  Sandusky,  Ohio   1250  240 

WBBA  Newark  Radio  Club,  Newark,  Ohio  •   1250  240 

WBBC  Sterling  Radio  Equipment  Co.,  Sterling,  111   1310  229 

WCBB  K  &  K  Radio  Supply  Co.,  Greenville,  Ohio  .   1250  240 


DELETIONS  FROM  MARCH  19  TO  APRIL  30 


KDYB   Salt  Lake  City,  Utah 

KDYY   Denver,  Colo. 

KDZA   Tucson,  Ariz. 

KDZL   Ogden,  Utah 

KDZM   Centralia,  Wash. 


KDZZ 

KFAS 

KFBV 

KFCC 

KFGG 

KHD 

KLP 

KOG 

KON 

KQP 

KXS 

KZC 

KZI 

WAH 


Everett,  Wash. 
Reno,  Nev. 

Colorado  Springs,  Colo. 
Wallace,  Idaho 
Astoria,  Oreg. 
Colorado  Springs,  Colo. 
Los  Altos,  Calif. 
Los  Angeles,  Calif. 
San  Diego,  Calif. 
Hood  River,  Oreg. 
Los  Angeles,  Calif. 
Seattle,  Wash. 
Los  Angeles/Calif. 
EI  Dorado,  Kans. 


WBAG  Bridgeport,  Pa. 


WCAP 


Decatur,  II 


WEAC   Terre  Haute,  Ind. 

WEAE   Blacksburg,  Va. 

WEAW   Anderson,  Ind. 

WFAD   Salina,  Kans. 

WFAS   Fort  Wayne,  Ind. 

WFAY   Independence,  Kans. 

WGAB   Houston,  Tex. 

WGAK   Macon,  Ga. 

WGAT   Lincoln,  Nebr. 

WIAZ    Miami,  Fla. 

WLAM   Springfield,  Ohio 

WMB    Auburn,  Me. 

WNAK   Manhattan,  Kans. 

WNO    Jersey  City,  N.  J. 

WOAQ   Portsmouth,  Va. 

WOAY   Birmingham,  Ala. 

WOZ    Richmond,  Ind. 

WPAV   Laurium,  Mich. 

WPAX   Thomasville,  Ga. 

WRAJ   Pittsburgh,  Pa. 

WSAS   Lincoln,  Nebr. 


What  Would  You  Like  to  Have  in  Radio  Broadcast? 

The  editors  would  he  pleased  to  hear  from  readers  of  the  magazine  on  the  following  {or  other)  topics: 

1.  The  kind  of  article,  or  diagram,  or  explanation,  or  improvement  you  would  like  to  see  in 
Radio  Broadcast. 

2.  What  has  interested  you  most,  and  what  least,  in  the  numbers  you  have  read  so  far. 


Eighteen  Years  of  Amateur  Radio 


In  Touch  with  the  World  from  the  Arctic 


Published  by  DOUBLEDAY,  PAGE  &  CO.  Garden  City,  N.  Y. 


One  of  the  World's 
Largest  Manufacturers 
with  unlimited  resources 
Builds  Cunningham  Tubes 

FORTY-THREE   years   ago  the  carbon   filament  electric  lamp, 
at  that  time  considered  the  finest  development  in  the  electrical 
art,  came  into  general  use. 
The  important  and  ever-growing  demand  resulted  in  the  building 
and  expansion  of  mighty  factories,  and  the  improvement  of  factory 
methods,    until  to-day  the   tungsten  filament   gas-filled   lamp  yields 
eight  times  the  candle  power  for  the  same  electric  input. 

In  recent  years  these  same  highly  skilled  manufacturers  have  been 
devoting  a  part  of  their  factories,  and  applying  their  engineering 
talent  gained  through  years  of  experience,  to  the  production  of 
vacuum  tubes. 

The  new  Cunningham  type  C-301-A,  Amplifier  and  Detector 
represents  a  combination  of  these  years  of  manufacturing  expe- 
rience, and  the  engineering  ability  contributed  by  that  great  scien- 
tific organization,  the  Research  Laboratory  of  the  General  Electric 
Company. 

The  low  filament  current  of  only  one-fourth  of  an  ampere  and 
the  extremely  high  mutual  conductance  of  700  micro-mhos,  make 
the  C-301-A  the  most  efficient  vacuum  tube  ever  built  for  amateur 
and  entertainment   use  in  radiu. 

Paf^nf   Mrtfr  !ro  •   Cunningham  tubes  are  cov- 

raient  i^once.  errd  by  paUnts  dated  w-i- 

05,  1-1  5-07,  2-18-08.  and  others  issued  and  pending. 
Licensed  for  amateur,  experimental  and  entertainment 
use  in  radio  communication.  Any  other  use  will  be 
an  infringemetit. 


A  Specially 
Designed  Tube 
For  Every 
Radio  Use 


Home  Offices: 
248  First  Street 
San  Francisco,  Calif. 


Eastern  Representatives: 
145  West  Lake  Street 
Chicago,  Illinois 


■jt  Tested  and  approved  by  Radio  Broadcast  -jr 


RADIO  BROADCAST  ADVERTISER 


mm. 


Perfect  Performance  Guaranteed 


Ace  Type  V,  Armstrong  Regenerative  Receiver — $20 — Formerly  known  as 
Crosley  Model  V.    For  performance  no  receiver  at  its  price  can  equal  it. 

A  man  writing  from  Evansville,  Ind.  says,  "The  other  night  I  tuned  in 
Kamach,  Hawaii  and  held  the  concert  for  one  hour.  The  music  was  clear 
and  the  speaking  distinct."    Quite  a  tribute. 

Ace  Receivers  are  licensed  under  Armstrong  U.  S.  Patent  1,113,149.  All 
Ace  sets  are  equipped  with  the  Crosley  multistat,  the  universal  filament  con- 
trol rheostat  for  all  makes  of  tubes. 

Wave  length  range  200  to  600  meters. 


Announcement 
A      TYPE  3  B 
A£E  $50. 


a  new  3  tube  Armstrong  Regen- 
erative set  with  filament  switch, 
jack,  new  Crosley  molded  sock- 
ets and  new  Crosley  Condensers  with  molded  plates.  This  is  one  of  the  latest  and  most  effi- 
cient sets  on  the  market  for  steady  performance.  Battery  cabinet  and  bench  can  be  fur- 
nished as  extra  equipment  if  desired.  There  is  also  a  Model  3  B  portable  for  camping  trips 
and  outings. 

Live  Jobbers  and  Dealers  are  taking  advantage  of  the  sales  these  instruments  and  other  Pre- 
cision instruments  and  parts  are  bringing  them. 

Free  Catalogue  on  Request 

The  Precision  Equipment  Company 


POWEL    CROSLEY,  Jr.,  President 


820  Gilbert  Ave. 


Cincinnati,  O. 


WW  % 

n  w 


it  Tested  and  approved  by  Radio  Broadcast  Vkr 


Radio  Broadcast 

ARTHUR  H.  LYNCH,  Editor 


CONTENTS  FOR  AUGUST,  1923 

An  Aid  in  the  Fight  Against  Crime  -    --    --    --    --    --    --    --    --    --  Frontispiece 

THE  MARCH  OF  RADIO  ------  ---------    J.  H.  M.  269 

IN  TOUCH  WITH  THE  WORLD  FROM  THE  ARCTIC  -----     Burnham  McLeary  282 

A  DRY-CELL  TUBE  LOOP  SET  FOR  LOCAL  RECEPTION    -   -   -   -     Alex.  V.  Polson  288 

EIGHTEEN  YEARS  OF  AMATEUR  RADIO    --------       George  E.  Burchard  290 

"SELLING"  THE  PUBLIC  ON  BETTER  CITY  GOVERNMENT  -    -    -    -     J.L.Simpson  299 

ADVENTURES  IN  RADIO— When  Messina  was  Destroyed  ------------  303 

PORTO  RICO  FAN  WINS  "HOW  FAR?"  CONTEST 

A  Neighbor  at  Three  Thousand  Miles  -    --   --    --    --    -     Richard  Bartholomew  304 

UNLOADING  THE  MAIL  FROM  THE  TRANSATLANTIC  LINERS     -   -     M.G.Carter  311 

THE  GRIMES  CIRCUIT  WITH  OUTDOOR  ANTENNA  AND  COUNTERPOISE 

Herbert  E.  Dill  314 

RADIO  ANGLING  AND  FISHERMAN'S  LUCK  -   -------  The  Rev.  H.  F.  Huse  316 

CRYSTAL  RECEIVERS  ARE  WELL  WORTH  WHILE  -   -     Zeh  Bouck  319 

POWEL  CROSLEY,  JR.    "THE  HENRY  FORD  OF  RADIO"-   -    Alvin  Richard  Plough  323 

RECEPTION  DE  LUXE     ------------------      A.  R.  Boscow  325 

TEACHING  SCHOOL  FROM  A  BROADCASTING  STATION    -----    Lloyd  Jacquet  331 

A  TABLET  DEDICATED  TO  THE  RADIO  CONGREGATION     ----------  332 

ALL  BOY  SCOUTS,  ATTENTION!  ---------------------  335 

SETS  FOR  THE  GREAT  OUTDOORS     ---------------    A.  Henry  336 

A  PRACTICAL  SUPER-HETERODYNE  WITH  109'S   -    -    -    -    -  Walter  Van  B.  Roberts  340 

A  NEW  REGENERATIVE  RADIO-FREQUENCY  COMBINA  TION    -    -    Roger  A.  Weaver  346 

THE  GRID— QUESTIONS  AND  ANSWERS     -----------------  350 

ADDITIONAL  BROADCASTING  STATIONS  IN  THE  UNITED  STATES      ------  352 

NEW  EQUIPMENT  -   -  ------  _   .   .  354 

AMONG  OUR  AUTHORS  -   -   -   -   -   -   -   -   356 

Copyright,  1923,  by  Doubleday,  Page  &  Co.    All  rights  reserved 
TERMS:  $3.00  a  year;  single  copies  25  cents 
F.  N.  Doubleday,  Pres.  Arthur  W.  Page,  Vice-Pres.  Nelson  Doubleday,  Vice-Pres. 

Russell  Doubleday,  Sec'y.  S.  A.  Everitt,  Treas.  John  J.  Hessian,  Asst.  Treas. 

DOUBLEDAY,  PAGE  &  CO. 

The  World's  Work       Country  Life       The  Garden  Magazine       Short  Stories       Educational  Review 

CHICAGO:  People's  Gas  Bldg.                             GARDEN  CITY,  N.  Y.                          NEW  YORK:  120  W.  32nd  Street 
BOSTON;  Tremont  Bldg.                  LOS  ANGELES:    Van  Nuys  Bldg. 


RADIO  BROADCAST  ADVERTISER 


/gadio-Bli 


i  t 

/  CKOck  Market  Report 

*  - 


ans  Buff" 


feather 


Picking  your  program  with  a  single  circuit  receiver  is  a  whole  lot 
like  playing  blind-man's  buff.  You're  not  sure  what  you'll  catch — 
nor  how  long  you'll  hold  it. 

In  the  midst  of  the  entertainment  you  selected  some  other  broad- 
casting station  is  quite  likely  to  cut  in  and  spoil  the  fun. 

Selecting  your  radio  equipment  with  your  eyes  open  avoids  this 
nuisance  of  jamming  and  scrambled  messages. 

Any  radio-wise  amateur  will  tell  you  that  there's  no  comparison  in  genuine 
satisfaction  between  a  single  circuit  instrument  and  the  Paragon  three-circuit 
receiver. 

PARAGON 


Reg.  U.  S.  Pat.  Off. 


RADIO  PRODUCTS  * 


The  amateur  will  tell  you  that  the 
Paragon  three-circuit  receiver,  because 
of  its  great  superior  selectivity  and 
sensitivity,  can  pick  and  choose  be- 
tween broadcasting  stations  of  about 
the  same  signal  strength  with  less  than 
one  per  cent  differential. 

This  means  that  with  a  Paragon  re- 
ceiver you  get  what  you  want  when  you 
want  it — complete  messages  and  clear 
music  from  the  station  you  tune  in  on, 
without  interruption  and  jamming. 
Until  you  have  listened  in  with  a 
Paragon  three-circuit  receiver,  you 
cannot  guess  the  real  pleasure  and  fas- 
cination of  radio. 


Also  Manufacturers  o/  PARAGON 

Radio  Telephone  Amplifier 

Transmitters  Transformers 

V.  T.  Control  Units  Control  Dials 

Rheostats  Amplifiers 

Potentiometers  Receivers 

V.  T.  Sockets  Switches 

Detectors  Variometers 


Long  before  broadcasting  popular- 
ized radio  with  the  general  public, 
Paragon  equipment  was  the  choice  of  the 
experienced  amateur.  He  will  tell  you 
today  that  if  you  want  quality  and  satis- 
faction, Paragon  Radio  Products  are 
the  best  and  safest  buy  on  the  market. 

An  illustrated  Catalog  of  Paragon 
Radio  Products  Is  Yours  For  the  Asking 

DEALERS — The  Adams-Morgan  Company 
has  an  interesting  proposition  to  make  to  rep- 
utable radio  dealers  who  believe  in  quality 
merchandise.     Details  on  request. 

ADAMS-MORGAN  COMPANY 
10  Alvin  Ave.,  Upper  Montclair,  N.  J. 


Type   RD-5   Regenerative  Receiver 

and  Detector — S75.00 
Type  A-2  Two- Stage  Amplifier— $50.00 
(Licensed  under  Armstrong  Patents.) 


if  Tested  and  approved  by  Radio  Broadcast 


JUL  20  1323 


(^C1B  581481 


RADIO 
BROADCAST 


Vol.  3    No.  4 


August,  1923 


The  March  of  Radio 

BUYING  SETS  ON  THE  INSTALLMENT  PLAN 

THERE  are  undoubtedly  many  homes 
where  a  good  receiving  set  would  be 
welcome,  which  have  up  to  now 
missed  the  evening's  radio  entertain- 
ment because  of  the  rather  high  cost 
of  a  good  radio  outfit.  To  get  the  sort  of  appa- 
ratus which  will  operate  a  loud  speaker  satis- 
factorily requires  in  the  neighborhood  of  S200, 
including  a  good  loud  speaker.  For  the  set 
alone  it  will  be  necessary  to  give,  perhaps,  f  125, 
if  stations  a  thousand  miles  distant  are  to  be 
picked  up  with  any  degree  of  ease  and  cer- 
tainty. 

Now  such  an  expenditure  is  often  impossible 
in  the  form  of  a  cash  payment  and  one  wide- 
awake company — The  American  Radio  and 
Research  Corporation — has  realized  this  and 
by  associating  itself  with  a  reputable  credit 
house,  has  arranged  to  sell  its  sets  so  that  they 
are  available  to  the  public  on  the  partial  pay- 
ment plan.  A  10  per  cent,  deposit  for  the  set, 
and  time  payments  extending  over  a  year,  will 
enable  the  family  to  enjoy  radio  while  they 
are  paying  for  the  set.  Of  course  many  people 
feel  that  if  they  cannot  afford  to  pay  cash  for 
an  article,  they  cannot  afford  it  at  all;  to  these, 
the  scheme  offers  nothing.  But  there  are 
thousands  of  families  willing  to  go  into  a  con- 
tract to  pay  for  some  luxury,  who  would  have 
to  do  without  it  if  the  contract  plan  were  not 
in  existence.  This  fact  is  evidenced  by  the 
tremendous  popularity  of  the  partial  payment 
plan  in  the  automobile  industry;  probably 


more  than  half  the  cars  purchased  to-day  are 
obtained  in  this  manner.  And,  we  may  ask, 
how  many  of  us  pay  cash  for  our  . homes? 

Those  who  depend  upon  the  small  boy  of  the 
family  to  buy  the  parts  and  assemble  the  set 
are  probably  fairly  well  "sold"  by  this  time; 
but  a  purchasing  public,  numbering  millions,  is 
still  to  be  equipped  with  radio.  With  new 
stations  going  up,  and  the  programs  of  the 
older  ones  continually  increasing  in  excellence, 
this  part  of  the  public  is  waiting  to  purchase 
radio  sets  which  require  no  tinkering  nor 
complicated  adjustments  before  they  are  ready 
to  provide  entertainment.  These  sets  will,  for 
some  time  to  come,  probably  be  sufficiently 
expensive  to  warrant  the  use  of  the  policy  of 
delivering  the  goods  to  the  customer  for  a  very 
small  payment  and  relying  on  the  pleasure 
which  is  had  by  the  purchaser,  to  keep  further 
payments  coming  in  on  time. 

Incidentally,  this  will  do  much  to  help  kill  off 
the  pour  trash  on  the  market,  because  if  such 
apparatus  is  bought 
on  the  installment 
plan,  the  family 
will  sacrifice  the 
first  payment  and 
give  back  the  set 
rather  than  con- 
tinue to  pay  for 
something  which  is 
not  what  it  is  rep- 
resented to  be. 


270 


Radio  Broadcast 


PREPARING  MESSAGES  TO  BE  SENT  AT  80  WORDS  A  MINUTE 
This  operator,  on  the  S.  S.  Majestic,  is  using  a  perforating  machine  to  make  records  of  radio  messages  on  a  tape.  The 
work  is  done  at  a  time  when  traffic  is  slack.    When  the  ship  nears  port  and  a  great  deal  of  business  has  to  be  rushed 
through,  the  tape  is  fed  into  an  automatic  transmitting  apparatus  and  buzzed  off  in  short  order 


Music  Publishers  With  Vision 

WE  HAVE  several  times  had  occasion 
to  express  our  disapprobation  of 
the  action  of  the  popular  music 
writers  in  prohibiting  the  broadcasting  of  any 
of  their  compositions  without  the  payment  of 
rather  large  license  fees.  The  recent  action 
of  the  Radio  Corporation  in  cutting  out 
from  their  programs  all  compositions  con- 
trolled by  the  Society,  evidently  verified  our 
guess  that  this  grasping  after  revenues,  where 
none  was  in  sight,  would  react  to  the  de- 
triment of  these  composers  and  publishers. 
It  is  with  real  pleasure  that  we  now  record 
the  action  of  another  group  of  music  com- 
posers and  publishers;  producers  of  the  so-called 
"standard"  music,  as  contrasted  to  the  "popu- 
lar" variety. 

In  a  report  on  the  subject  of  broadcasting,  a 


committee  of  the  Music  Publishers'  Association 
of  the  United  States  says:  "Our  committee 
has  been  carefully  investigating  the  broadcast- 
ing of  copyrighted  music  since  last  November. 
In  our  report,  just  adopted  by  the  Association, 
we  point  out  that  music  publishers  are  vitally 
interested  in  radio  broadcasting  as  a  great 
future  user  of  music  and  that  our  rights  in  the 
use  of  copyrighted  music  in  public  performances 
must  be  protected.  However,  we  appreciate 
the  fact  that  radio  broadcasting  is  still  in  a 
chaotic  and  experimental  state,  and  that  while 
ultimately  it  will  have  to  be  placed  on  a  com- 
mercial basis  if  it  is  to  develop  its  potentialities, 
nevertheless  the  commercial  side  of  the  broad- 
casting problem  has  not  yet  been  solved. 

"  In  view  of  these  facts,  and  also  because  we 
desire  to  cooperate  in  developing  the  music  pos- 
sibilities of  radio,  we  believe  that  we  should 
allow  the  use  of  our  copyrighted  compositions 


SOME  OF  THOSE  RESPONSIBLE  FOR  THE  NATIONAL  ASSOCIATION  OF  BROADCASTERS 

Left  to  right:  J.  E.  Jenkins,  of  WDAP,  Drake  Hotel,  Chicago;  Frank  J.  Elliot,  WOC,  Davenport,  Iowa;  Henry  Ramsey, 
Chicago  Board  of  Trade;  Thorne  Donnelly,  WDAP;  E.  F.  McDonald,  Jr.,  WJAZ,  Edgewater  Beach  Hotel,  Chicago;  and 

W.  Johnson,  WFV 


for  broadcasting  without  charge  for  the  present 
and  without  prejudice  in  our  rights." 

In  another  part  of  the  report  the  musical 
possibilities  of  radio  are  hinted  at  and  present 
defects  mentioned ;  altogether  the  report  shows 
keen  analysis  and  liberal  judgment  of  the 
members  of  this  organization,  and  we  heartily 
recommend  its  perusal  (especially  the  italicized 
part)  by  the  more  short-sighted  members  of 
the  American  Society  of  Composers,  Authors, 
and  Publishers. 

Will  the  Composer  Pay  for  Broadcasting? 

MANY  and  varied  have  been  the  sug- 
gestions volunteered  to  solve  the 
question — who  is  going  to  pay  for 
broadcasting?  This  was  the  subject  of  our 
first  editorial  in  the  very  first  number  of  our 
magazine;  it  seemed  at  that  time  the  one 
important  question  involved  in  the  future 
development  of  radio,  to  which  no  satisfactory 
workable  answer  had  been  given .  To-day,  more 
than  ever,  this  question  is  uppermost  in  the 


minds  of  those  concerned  with  the  future  of 
broadcasting. 

There  are  two  large  organizations  interested 
in  the  question  which  can  get  along  indefinitely 
with  conditions  as  they  are:  undoubtedly  the 
Radio  Corporation  has  a  large  income  from  the 
sales  of  tubes  and  sets,  and  the  American  Tele- 
phone and  Telegraph  Company  can  charge  up 
its  broadcasting  expense  to  development  with- 
out seriously  reducing  its  dividend.  But  there 
are  scores,  or  even  hundreds,  of  broadcasting 
stations  which  cannot  continue  in  this  fashion. 
Their  future  is  not  promising  unless  some  source 
of  revenue  is  found  and  found  soon.  This  is 
especially  true  since  the  popular  music  writers 
have  begun  to  insist  on  their  royalty  rights  and 
want  to  collect  money  where  there  is  none. 

Now,  the  American  Society  of  Composers, 
Authors,  and  Publishers  undoubtedly  numbers 
among  its  members  many  of  the  better  writers 
and  composers  of  popular  music,  but  we  have 
wondered  of  late  if  it  were  not  possibly  adopt- 
ing tactics  like  those  of  some  labor  unions,  sup- 
pressing potential  talent  so  that  those  in  the 


272 


Radio  Broadcast 


Society  might  better  control  the  dividend 
sources.  Although  we  have  never  tried  the 
experiment  (not  having  sufficient  gift  along 
musical  lines)  we  imagine  that  a  new  song  and 
score  writer,  not  in  the  Society,  and  not  wanted 
in  it,  might  have  quite  a  difficult  time  getting 
his  wares  on  the  market.  If  this  is  so,  the 
scheme  outlined  in  the  pamphlet  before  us 
may  succeed  very  well,  and  in  succeeding, 
indicate  at  least  one  way  in  which  broadcast- 
ing may  be  made  self-supporting. 

A  group  of  broadcast  managers  have  com- 
bined to  form  the  nucleus  of  the  National  As- 
sociation of  Broadcasters.  The  proposed  con- 
stitution and  by-laws  are  well  drawn  up  and 
show  the  executive  ability  of  the  organizers. 
Membership  in  the  Association  is  suitably  di- 
vided into  classes,  and  other  formalities  are 
taken  care  of  properly,  such  as  membership 
fees,  schedules  for  broadcasting,  and  care  of 


surplus  funds.  The  mention  of  this  last  item 
started  us  thinking.  Surplus  funds  from  the 
operation  of  a  broadcasting  station! 

Well,  here's  the  idea.  Musical  genius  is  to 
turn  over  its  compositions,  properly  copy- 
righted, to  the  Association — for  nothing.  The 
Association  will,  through  its  members,  put  the 
composition  "on  the  air"  and  so  bring  it  at 
once  to  the  public's  attention  and  if  the  listen- 
ers think  the  stuff  is  good  the  composer's  pro- 
duct is  "sold."  The  composer  begins  to  reap 
his  royalties  from  the  publication  and  sale  of 
his  music,  and  the  Association,  as  its  reward 
for  putting  the  music  before  the  public,  is  to 
get  the  mechanical  royalties — those  reaped 
from  phonograph  records  and  roll  music. 
When  the  composer  turns  his  work  over  to  the 
Association  to  broadcast,  these  mechanical . 
royalties  are  conveyed  to  it  in  the  contract. 

This  looks  like  a  very  good  scheme,  and  we 


RESERVE  OFFICERS  AT  CAMP  VAIL.  NEW  JERSEY 
Using  an  outfit  with  a  collapsible  loop.    With  this  little  machine  it  is  possible  to  send  and  receive, 
even  though  located  deep  in  a  dug-out.    This  set  was  developed  by  William  Preiss  during  the  War 


The  March  of  Radio 


273 


shall  watch  its  development  with  interest. 
All  stations  represented  in  the  Association  will 
send  out  the  compositions  contracted  for  by  the 
society,  on  a  schedule  arranged  by  the  Board  of 
Directors,  so  that  a  definite,  known  advertising 
campaign  is  assured  to  the  composer.  It  is 
for  the  best  interests  of  both  parties  to  the 
contract  that  the  new  piece  be  "put  over", 
because  both  benefit  from  large  sales.  As 
far  as  we  can  see,  composers  and  broadcasters 
alike  have  everything  to  gain  and  nothing  to 
lose  in  trying  out  the  scheme.  If  it  works,  as 
we  hope  it  will,  societies  like  the  A.  S.  C.  A.  P., 
which,  have  been  so  insistent  on  radio  royal- 
ties, will  have  to  look  elsewhere  for  funds  to  pay 
their  eminent  counsel. 

In  outlining  the  need  for  this  society,  one  of 
its  organizers  informed  us  of  the  following  in- 
cident, which,  he  maintains,  is  but  one  of  a 
number: 

An  author  sold  one  of  his  compositions  to  a 
Chicago  music  house.  It  remained  dormant 
for  a  long  time.  Later,  arrangements  were 
made  with  a  broadcasting  station  to  have  the 
author  sing  his  own  song.  It  made  quite  a 
hit  and  has  enjoyed  a  good  sale.  Radio  has 
actually  brought  this  author  out  of  obscurity. 
Then,  because  the  author  had  made  an  arrange- 
ment with  the  A.  S.  C.  A.  P.,  he  was  prevented 
from  singing  his  own  song  at  all  radio  stations 
that  failed  to  pay  royalties  to  his  society. 

The  new  Association  is  made  up  of  some  of 
the  leading  broadcasters  in  the  country  and 
they  have  very  good  ground  for  the  belief  that 
they  are  in  a  position  to  popularize  their  own 
songs.  Powel  Crosley,  Jr.,  a  member  of  the  As- 
sociation, has  already  started  a  music  publish- 
ing company  and  the  first  song  to  be  popular- 
ized by  radio  is  now  being  put  on  the  air.  Is 
this  the  handwriting  on  the  wall? 

The  Effect  of  Broadcasting  on  the 
Churches 

ON  TWO  recent  occasions  we  have  com- 
mented on  the  effect  of  broadcasting 
upon  church  attendance.  It  is  evi- 
dent that  effects  of  considerable  importance 
may  be  looked  for.  We  had  ventured  the 
guess  that  the  smaller  churches  would  prob- 
ably lose  in  attendance  as  the  worshippers  at 
these  small  country  churches,  with  their  itin- 
erant pastors,  came  more  directly  in  contact 
with  services  at  the  larger  metropolitan  church 
with   their  wonderful   music   and  inspiring 


THE  HONORABLE  ERNEST  LAPOINTE 
Canadian  Minister  for  Radio.  He  is  to  supervise  the 
activities  of  the  twenty-odd  broadcasting  stations  and 
arrange  for  the  collection  of  the  $  1 .00  tax  levied  on  every 
broadcast  receiver.  It  is  estimated  that  there  are  more 
than  1 50,000  receiving  sets  in  use  in  Canada  at  the 
present  time 

preachers.  It  seemed  to  us,  also,  that  an 
argument  might  be  found  on  the  other  side  of 
the  question:  the  country  pastor,  ordinarily 
having  but  little  contact  with  the  larger 
churches,  administered  by  the  more  capable 
preachers  of  his  denomination,  might  himself 
install  a  receiving  set,  and  so  gain  ideas  and 
inspiration  for  his  own  services.  Ordinarily, 
he  is  dependent  upon  the  printed  word  for  his 
sermons,  but  by  radio  he  is  put  directly  into 
the  audience  of  the  best  thinkers  and  speakers 
of  his  church.  In  this  way,  we  believed,  he 
must  improve  himself,  and  this  improvement 
might  result  in  the  increased  interest  of  his 
own  little  band  of  worshippers. 

These  were  only  guesses,  as  most  of  the 
opinions  on  the  effect  of  radio  broadcasting 
must  be  for  some  time;  but  that  the  guesses 
come  somewhere  near  the  mark  would  appear 
from  a  recent  letter  in  which  an  Episcopal 
bishop  voices  his  ideas  on  radio.  The  letter 
is  from  Bishop  Steady,  and  reads  as  follows: 


Radio  Broadcast 


USING  A  YOUNG  BLIMP  TO  SUSPEND  THE  ANTENNA 

Mr.  Roy  Knabenshue,  of  Burbank,  Calif.,  a  pioneer  aeronaut,  constructed  this  14-foot  balloon,  filled  it  with  hydrogen,  and 
sent  it  up  with  200  feet  of  antenna  wire  attached.    Using  a  commercial  two-stage  receiver,  he  claims  to  have  received 
various  broadcasting  programs  with  greater  clearness  than  when  using  a  horizontal  antenna  suspended  in  the  ordinary 
way.    Mrs.  Knabenshue  and  Mr.  R.  W.  Coburn  (on  either  side  of  Mr.  Knabenshue)  assisted  in  the  experiments 


The  wide-spread  use  in  private  homes  of  the  wire- 
less apparatus  lays  a  fresh  responsibility  upon  the 
clergy  and  laity  in  regard  to  services  of  the  church. 
It  is  debatable  whether  the  broadcasting  of  sermons 
of  popular  preachers  and  of  entire  church  services 
will  act  as  a  stimulant  or  a  deterrent  to  church- 
going. 

Why  go  to  your  parish  church  when  you  can  sit 
at  ease  in  your  parlor  and  hear  the  heavenly  music 
of  a  capable  choir  and  be  charmed  by  the  fervid  elo- 
quence of  a  magnetic  preacher? 

There  seems  to  have  entered  into  our  crowded  and 
throbbing  life  another  ally  of  those  forces  which 
make  difficult  the  assembling  of  the  faithful  for 
praise  and  prayer.  The  habit  of  church-going  has  a 
hard  time  in  the  face  of  Sunday  excursions,  movies, 
sacred  concerts,  automobiling,  and  broadcasting. 

What  this  means  to  us,  I  suspect,  is,  at  the  bottom, 
a  challenge  to  our  ingenuity,  wisdom,  and  de- 
votion. None  of  these  things,  nor  all  of  them  to- 
gether, can  fill  the  deepest  need  of  the  spirit  in  man, 


and  in  the  church,  in  its  worship  and  teaching  and 
work  and  fellowship,  are  the  potencies  capable  of 
bring  to  men  the  highest  satisfaction,  the  deepest 
and  most  abiding  joys. 

Now  it  becomes  necessary  for  the  clergy  to  make 
the  church  more  attractive  than  the  world's  enter- 
tainments, to  discover  to  men  the  possibilities 
within  it  for  strength  and  refreshment,  and  the  gifts 
of  grace  in  its  bestowing,  more  precious  than 
earthly  things. 

Broadcast  Central,  Comprising  WJZ 
and  WJY 

THE  past  month  saw  the  opening  of 
probably  the  best  equipped  radio  broad- 
casting station  in  America,  the  Radio 
Broadcast  Central  of  the  Radio  Corporation 
of  America.  It  is  located  on  the  top  of  Aeolian 
Hall,  one  of  New  York's  tall  buildings  in  the 


The  March  of  Radio 


275 


centre  of  the  city.  Trouble  from  power  ab- 
sorption in  the  neighboring  buildings,  and  poor 
radiation,  might  have  been  anticipated,  but 
from  results  so  far  reported  the  station  seems 
to  function  excellently. 

The  Radio  Corporation's  previous  broad- 
casting station,  WJZ,  located  in  Newark,  a 
dozen  miles  from  New  York,  was  extremely 
inaccessible  to  lecturers  and  performers.  This 
drawback  was  partially  remedied  by  fitting  up 
a  studio  in  New  York  City,  and  sending  the 
voice  currents  by  wire  to  the  radio  station. 
But  this  scheme  gave  much  trouble;  the  wires 
used  were  leased  from  the  Western  Union 
Telegraph  Company,  and  in  spite  of  assurances 
that  they  were  "as  quiet  as  it  was  possible  to 
make  them,"  noises  of  all  sorts  were  picked  up 
by  them  between  the  studio  and  the  trans- 
mitting station.  In  fact,  on  the  night  when 
they  were  first  put  in  commission,  while  the 


Western  Union  official  was  telling  us — via 
radio — how  quiet  his  wires  were,  they  were 
picking  up  so  much  extraneous  noise,  unknown 
to  him,  that  his  words  were  scarcely  intelligible. 

A  studio  and  radio  transmitter  should  be  as 
close  together  as  it  is  possible  to  make  them, 
because  wire  connections  between  them  even 
under  the  best  conditions  will  pick  up  some 
disturbing  "electrical  noises."  Broadcast  Cen- 
tral's studios  (there  are  two  of  them)  are  di- 
rectly under  the  antenna,  so  that  trouble  from 
this  source  has  been  eliminated. 

Two  antennas,  suspended  from  the  same 
masts,  lead  to  two  entirely  separate  trans- 
mitting sets,  each  of  which  has  its  own  control 
equipment.  Each  studio  controls  one  of  the 
antennas,  and  as  these  and  their  respective 
transmitters  are  tuned  for  different  wave- 
lengths, both  studios  and  antennas  may  oper- 
ate simultaneously  without  interference.  This 


A  PLACE  FOR  EVERYTHING  AND  EVERYTHING  IN   ITS  PLACE 

Amateur  station  2ABT,  owned  by  Mr.  George  Freisinger  of  New  York.  It  is  one  of  the  most  elaborate  in  the  East,  and  its 
performance  is  in  keeping  with  its  appearance,  as  Mr.  Freisinger  (at  right  of  picture)  has  heard  stations  in  Europe  as  well 
as  all  over  America.  The  300-watt  transmitter  is  not  shown,  but  the  combination  transmitter  and  receiver  of  the  navy 
type,  using  20-watt  Singer  tubes  for  transmitting,  and  a  standard  honeycomb  regenerative  hook-up  with  two  stages  of 
amplification  for  receiving,  is  mounted  on  the  desk  at  the  left.  In  the  centre  is  a  special  type  amateur  receiving  unit 
with  two  stages  of  A.  F.  amplification.    At  the  right,  is  a  three-stage  power  amplifier 


276 


Radio  Broadcast 


is  the  first  time  such  a  system  has  been  intro- 
duced into  the  broadcasting  game. 

These  paragraphs  do  not  pretend  to  give  a 
technical  description  of  WJY  and  WJZ,  but 
one  very  ingenious  scheme  of  control  does 
warrant  mention  here;  the  visual  control  of 
the  amount  of  modulation  of  the  antenna  cur- 
rent. The  high-frequency  antenna  current  is 
rectified  by  a  tube  outfit  and  thrown  on  to  an 
oscillograph  screen,  and  a  wavy  line  of  light 
shows  the  operator  exactly  how  much  the 
antenna  current  is  being  varied  by  the  singer's 
voice.  Moreover,  this  operator  has  at  his  im- 
mediate command  the  control  of  the  amount  of 
modulation  sent  to  the  antenna — if  a  singer 
puts  too  much  fortissimo  into  her  voice  so 
that  the  entenna  current  would  be  modulated 
too  much  to  sound  well,  the  effect  of  the  voice 
on  the  antenna  current  can  be  at  once  (and 
unknown  to  the  singer)  cut  down,  thus  tem- 


pering the  singer's  effect  on  the  transmitter. 
The  idea  is  very  much  like  having  an  or- 
chestra perform  in  a  room  enclosed  by  shutters 
which  could  be  opened  or  closed  by  a  listener 
outside;  if  the  performers  put  too  much  in- 
tensity into  their  playing  the  outside  listener 
could  close  the  shutters  when  they  played  too 
loudly  and  open  them  when  the  softer  passages 
were  being  executed. 

Some  such  control  over  radio  modulation  is 
absolutely  essential  if  the  quality  of  the  re- 
ceived signal  is  to  be  good.  While  one  per- 
former will  sing  with  tremendous  volume,  and 
stand  close  to  the  microphone,  the  next,  stand- 
ing farther  from  the  microphone  and  singing 
with  less  force,  may  scarcely  affect  the  antenna 
current.  The  engineers  of  the  Radio  Corpora- 
tion are  to  be  congratulated  on  the  method 
which  they  have  developed  to  solve  this 
problem. 


THE  FIRST  DEMONSTRATION  OF  THE  RADIO  TAI L-E-PHON E 

The  scene  is  laid  in  Leadville,  Colorado,  in  1905,  when  Mr.  C.  B.  Cooper  (sitting  on  the  apparatus)  was  Superintendent 
of  Construction  for  the  United  Wireless  Company.  Mr.  Cooper  is  now  a  member  of  the  Hoover  Conference  Committee, 
the  Board  of  Governors  of  the  National  Radio  Chamber  of  Commerce,  and  Chairman  of  its  Broadcasting  and  Finance  Com- 
mittees, and  Treasurer  of  the  Radio  Broadcasting  Society  of  America.  In  1917,  he  left  construction  work  to  organize 
the  Ship  Owners'  Radio  Service,  in  Seattle.  Recently  he  started  the  C.  B.  Cooper  Company,  Factory  Representatives. 
His  company  acts  as  New  York  representative  for  the  Crosley  Manufacturing  Company 


The  March  of  Radio 


277 


LISTENING  TO  WJAZ  FROM  JUST  OUTSIDE  THE  STUDIO 
Guests  at  the  Edgewater  Beach  Hotel,  Chicago,  can  see  the  broadcasters  through  the  windows  at  the  left  and  the  control 
room  operators  through  the  windows  at  the  centre.    At  the  same  time,  they  can  listen  to  the  program  by  means  of  a 

receiver  and  loud  speaker 


Secretary  Hoover  Acts 

WE  BEMOANED  the  failure  of  Con- 
gress to  act  on  the  White  bill,  by 
which  the  broadcast  situation  was 
to  be  remedied;  but  before  the  echo  of  our 
moans  had  died  away  we  found  the  situation 
suddenly  remedied  without  the  White  bill! 
Apparently  feeling  that  it  already  had  sufficient 
authority,  and  that  the  situation  was  bad 
enough  to  warrant  immediate  action,  the  De- 
partment of  Commerce,  acting  in  accord  with 
the  opinion  of  the  radio  experts  and  authori- 
ties of  the  country,  has  reassigned  frequencies 
to  practically  all  the  broadcasting  stations 
in  the  country  and  has  done  it  so  well  that  we 
no  longer  have  any  cause  for  complaint.  In- 
stead of  the  bedlam  of  noise  to  which  we  had 
become  almost  accustomed,  there  is  practically 
no  interference  at  all.  With  a  good  receiving 
set,  one  can  go  through  the  range  of  wave- 
lengths assigned  to  broadcasting  and  pick  up 
perhaps  twenty  stations  with  no  appreciable 
interference. 


To  be  sure,  it  was  possible  for  the  expert, 
even  under  previous  conditions,  to  get  rid  of 
much  of  the  interference,  because  no  two  sta- 
tions sent  on  exactly  the  same  wavelength, 
and  by  using  two-  and  three-circuit  tuners  with 
just  the  right  amount  of  regeneration,  he  was 
able  to  cut  out  many  of  the  disturbing  stations. 
Most  of  us,  however,  were  not  sufficiently  ex- 
pert, and  didn't  have  sufficiently  complicated 
sets  (and  didn't  want  them,  either)  to  do  such 
fine  tuning.  But  now  no  such  skill  is  required. 
Even  the  novice  can  eliminate  practically  all 
interference;  and  the  concerts,  ever  improving 
in  quality,  are  really  worth  while  staying  at 
home  to  hear.  The  finer  passages  are  not 
spoiled  by  the  whining  beat  note  of  a  competing 
station,  as  they  formerly  were. 

With  this  re-assignment  of  wavelengths,  a 
big  step  has  been  taken  in  forwarding  the 
interests  of  radio  broadcasting;  considering  the 
apparent  ease  with  which  it  was  accomplished 
we  wonder  more  than  ever  why  the  Depart- 
ment of  Commerce  delayed  its  good  work  so 
long. 


278 


Radio  Broadcast 


THE   BOOM  IS  ON  IN  ENGLAND 
And  manufacturers  are  hard-put  to  supply  the  increasing  demand  for  broadcast  receivers. 
These  women  are  doing  light  assembly  work  at  the  Marconi  Works  in  Chelmsford 


The  Interdepartmental  Radio  Advisory 
Committee 

FROM  the  Department  of  Commerce  we 
have  received  a  bulletin  describing  the 
successful  functioning  of  the  committee 
of  representatives  from  all  governmental  de- 
partments having  a  serious  interest  in  radio 
communication.  For  some  time  past  various 
departments  have  been  doing  more  or  less 
broadcasting,  and  as  it  seemed  only  con- 
sistent with  the  Federal  Government's  activi- 
ties in  other  branches  of  coordinating  the  work 
of  various  government  sub-divisions  to  cut 
down  expense  and  interference,  Secretary 
Hoover  brought  about  in  April,  1922,  the  for- 
mation of  the  Interdepartmental  Radio  Ad- 
visory Committee,  which  we  discussed  in  these 
columns  about  a  year  ago.  The  scope  of  the 
Committee's  activities  was  widened  in  Jan- 
uary of  this  year  to  include  not  only  questions 
of  methods  of,  and  material  for,  broadcasting, 
but  all  other  radio  matters  in  which  the  several 
departments  may  be  interested. 

The  Chairman  of  the  Committee  is  Acting 
Assistant  Secretary  S.  B.  Davis  of  the  Depart- 
ment of  Commerce,  and  he  has  with  him  repre- 


sentatives of  the  Departments  of  Agriculture, 
Interior,  Justice,  Labor,  State,  Treasury,  War. 
and  Navy,  Bureau  of  the  Budget,  Interstate 
Commerce  Commission,  Post  Office,  and  the 
Shipping  Board.  Whereas  the  power  of  this 
committee  is  purely  advisory,  its  members 
have  cooperated  so  harmoniously  that  no  mat- 
ter has  yet  been  brought  up  for  consideration 
which  has  not  been  amicably  solved.  As  its 
fundamental  principle  in  controlling  the  ex- 
tension of  governmental  radio  activities,  the 
committee  has  wisely  concluded  "that  radio 
broadcasting  should  not  be  used  where  wire 
telegraphy  or  telephony  or  printed  publication 
would  be  as  satisfactory." 

In  the  words  of  the  bulletin,  "the  several 
departments  feel  that  the  committee  has  been 
a  satisfactory  clearing  house  for  government 
radio  matters.  While  the  experimental  broad- 
casting system  has  operated  satisfactorily  to 
date,  the  experience  which  has  been  had  with 
it  should  be  used  as  a  basis  of  a  rational  plan 
for  a  government  broadcasting  system.  The 
question  is,  of  course,  intimately  related  with 
the  existing  and  prospective  privately  owned 
broadcasting  stations  throughout  the  country. 
If  radio  is  to  become  of  maximum  benefit  to 


The  March  of  Radio 


the  people,  the  Government  must  continue  to 
study  the  question  of  properly  organized  broad- 
casting and  other  services.  There  are  con- 
stant occasions  for  the  curtailment  or  ex- 
pansion of  the  Government's  radio  plant  and 
the  committee's  effort  is  to  coordinate  these 
needs  and  fulfill  them  with  maximum  econ- 
omy." 

Radio  Repays  its  Genius 

TO  THOSE  who  have  followed,  even  su- 
perficially, the  development  of  radio  in 
America,  the  name  of  Alexanderson  is 
well  known.  The  contributions  which  have 
come  from  him  and  his  co-workers  are  many 
and  varied;  his  work  is  not  apparent  in  the 
receiving  sets  with  which  most  of  us  are  fa- 
miliar but  deals  rather  with  the  engineering 
features  of  radio.  The  reduction  of  losses  in 
the  huge  insulators  used  in  suspending  the  large 
antennas  of  the  Radio  Corporation's  trans- 
mitting stations,  the  ingenious  scheme  for  re- 
ducing earth  losses  of  an  antenna  by  his 
"multiple  tuning"  method,  the  magnetic  be- 
havior of  iron  at  the  excessively  high  frequencies 
used  in  radio,  and  the  design  and  construction 
of  the  immense  high-frequency  alternators 
which  bear  his  name,  serve  to  illustrate  the 
type  of  work  which  this  engineer  is  contribut- 
ing to  the  advancement  of  this  branch  of  elec- 
trical engineering. 

He  now  undoubtedly  feels  repaid  a  thousand- 
fold for  the  energy  he  has  devoted  to  radio 
research,  as  will  be  evident  from  the  following 
narrative  from  the  News  Bureau  of  the  General 
Electric  Company: 

Monday,  April  30,  Verner,  six-year-old  son 
of  Dr.  Alexanderson,  was  lured  from  his  home 
by  the  promise  of  a  gift  of  rabbits,  and  kid- 
napped. The  police  had  practically  no  clue  to 
work  on;  in  spite  of  the  active  work  and  close 
cooperation  of  the  newspapers,  police,  and  radio 
broadcasting  stations,  the  case  appeared  to  be 
at  a  standstill  and  the  whereabouts  of  the  boy 
remained  a  mystery  for  three  days. 

Bert  Jarvis,  of  Theresa,  Jefferson  County, 
N.  Y.,  a  village  of  a  thousand  inhabitants, 
listening-in  Monday  night  on  his  home-made 
radio  set,  heard  WGY,  the  Schenectady  broad- 
casting station  of  the  General  Electric  Com- 
pany, announce  the  kidnapping  of  Verner 
Alexanderson.  Jarvis  rents  boats  to  fishermen 
and  acts  as  caretaker  for  numerous  summer 
cottages  in  the  vicinity  of  Theresa.  A  few 
days  before  the  kidnapping,  he  had  rented  an 


279 


DR.  ALEXANDERSON   AND  HIS  SON 


isolated  cottage  to  a  man  who  was  bringing  his 
family  up  from  the  city  for  the  season. 

After  hearing  the  radio  description  of  the 
missing  boy  and  the  kidnapper,  Jarvis's  sus- 
picions were  aroused.  Tuesday  he  met  the 
owner  of  the  cottage  and  asked  him  who  had 
taken  possession.  The  owner  explained  that 
it  was  only  an  old  woman,  a  little  boy,  and  one 
man. 

It  so  happened  that  the  man  when  renting  the 
cottage  had  said  that  he  was  going  to  bring  his 
daughter.  Jarvis's  suspicions  grew  and  Wed- 
nesday he  decided  to  ride  out  to  the  vicinity 
of  the  cottage  in  his  motor  boat.  He  stopped 
at  the  cottage  and  asked  the  old  woman  who 
came  to  the  door  for  a  glass  of  water.  He 
entered  the  house  and  saw  a  child  on  the  bed. 
Jarvis  returned  to  the  cottage  later  and  asked 
for  candle  wicking  for  his  motor.  On  this 
visit  he  waved  to  the  boy  and  the  boy  waved 
at  him. 

Thursday  morning,  Jarvis  saw  a  photograph 
of  the  kidnapped  boy  in  the  Syracuse  Post 
Standard  and  this  picture  tallied  with  the  boy 
in  the  cottage.  Now  sure  of  his  ground,  Jarvis 
reported  to  the  Deputy  Sheriff  and  a  few  hours 


280 


Radio  Broadcast 


HOMEWARD  BOUND  WITH  THE  CAVE-MAN  SET 

HE  MADE  AT  SCHOOL 
This  English  youngster  is  eager  to  see  what's  on  the  air 
down  in  London.    The  apparatus  looks  a  bit  primitive 
hut  it's  easy  to  "get  at,"  at  least 


later  Verner  talked  over  the  long  distance 
telephone  to  his  father  and  mother. 

The  successful  use  of  radio  in  the  Alexander- 
son  case  has  convincingly  proved  the  value  of 
broadcasting  as  a  publicity  factor  when  far- 
reaching  results  are  desired  in  a  short  time. 
WGY  announced  the  kidnapping  within  two 
hours  after  it  had  been  reported  to  the  police. 
Other  broadcasting  stations  joined  their  voices 
to  the  voice  of  WGY,  and  the  story,  with  a 
description  of  the  missing  boy,  went  over  the 
entire  country.  Radio  fans  were  everywhere 
enlisted  in  the  search.  The  newspapers  kept 
them  posted  on  the  progress  of  the  case  and  also 
furnished  them  with  pictures  of  the  boy. 
Through  Hudson  Maxim,  the  members  of  the 
Amateur  Relay  League  took  up  the  case  and 
hundreds  of  spark  sets  flashed  the  story  through 
the  air. 

Dr.  Alexanderson  made  a  personal  appeal 
from  the  Schenectady  broadcasting  station. 
After  the  boy  had  been  found  he  again  ad- 
dressed the  radio  audience  thanking  everyone 
for  his  interest,  sympathy,  and  assistance.  He 
placed  special  emphasis  on  the  cooperation  of 
the  press  and  police. 


West  Coast  to  Have  a  New  Station 

TH  E  General  Electric  Co.  has  started  work 
on  a  new  broadcasting  station  to  be 
located  in  Oakland,  Cal.  Most  of  the 
broadcasting  stations  to  date  have  been  fitted 
up  in  more  or  less  makeshift  quarters  in  build- 
ings already  erected,  but  this  new  Western  sta- 
tion is  to  be  built  for  radio  from  the  ground  up. 

Research  is  being  carried  on  to  determine  how 
reverberatory  an  ideal  studio  should  be ;  a  room 
having  no  echoes  at  all  gives  the  transmission 
a  peculiar  empty  quality,  whereas  too  much 
echo  from  walls  and  ceiling  makes  the  speech 
unintelligible  and  accentuates  severely  certain 
musical  notes. 

A  small  power  house  for  the  radio  apparatus 
will  be  built  below  the  antenna,  which  will  be 
of  the  multiple  tuned  type.  An  interesting  fea- 
ture of  the  new  station  is  the  use  of  water- 
cooled  triodes  for  the  oscillator  and  modu- 
lator; although  the  normal  antenna  power  from 
these  tubes  will  be  only  iooo  watts,  the  possible 
output,  to  be  used  for  test  purposes,  will  be 
many  times  as  much. 

It  is  expected  that  the  programs  will  be 
broadcasted  not  only  from  artists  in  the  station 
studios,  but  that  also,  by  suitable  wire  con- 
nections provided  by  the  Pacific  Telegraph  and 
Telephone  Company,  any  of  the  interesting 
events  taking  place  in  San  Francisco,  the 
West's  metropolis,  will  be  put  on  the  air! 

The  U.  S.  Health  Service  Functioning  by 
Radio 

THAT  radio  is  surely  becoming  one  of  the 
very  necessary  factors  in  our  every-day 
life  is  evidenced  by  the  following  recent 
note  from  the  U.  S.  Public  Health  Service: 

The  steamship  West  Cahous,  lying  at  anchor  in 
Baltimore  harbor,  about  nine  miles  from  the  city, 
needed  medical  help  at  about  3  a.  m.  recently  and 
needed  it  quickly.  A  member  of  the  crew  had 
fallen  into  the  hold  and  injured  himself  seriously. 
So  the  captain  of  the  ship  sent  a  wireless  broadcast 
asking  help. 

The  call  was  picked  up,  not  in  Baltimore,  nine 
miles  away,  but  at  Cape  May,  about  100  miles  due 
east  of  Baltimore.  As  Cape  May  was  separated 
from  the  West  Cahous  by  parts  of  New  Jersey;  and 
Delaware  and  by  the  eastern  shore  of  Maryland,  not 
to  mention  Delaware  and  Chesapeake  bays,  no 
direct  help  from  it  was  possible. 

But  the  operator  was  on  the  job.  Promptly  he 
consulted  the  long  distance  list  in  the  Baltimore 
telephone  directory  and  called  up  the  residence  of 


The  March  of  Radio 


the  Public  Health  Service,  Surgeon-in-Charge  of  the 
Marine  Hospital  in  Baltimore — 100  miles  to  the 
west.  The  surgeon,  roused  from  sleep  to  receive 
the  message,  asked  him  to  radio  certain  emergency 
treatment  to  the  West  Cahous  and  to  direct  the 
captain  to  send  a  boat  to  a  certain  pier  in  Baltimore, 
where  he  would  find  a  surgeon  waiting  to  go  to  the 
ship  with  him.  And  so,  in  the  middle  of  the  night, 
in  less  than  an  hour  from  the  time  the  call  for  help 
was  sent,  a  sea-going  ambulance  carrying  a  Public 
Health  Service  officer  reached  the  side  of  the  in- 
jured sailor. 

Good  News  For  Our  Readers 

EVERY  one  really  interested  in  the  de- 
velopment of  radio  realizes  that  to 
understand  its  problems  a  knowledge 
of  its  more  technical  features  is  most  desirable. 
Of  course,  we  cannot  all  expect  to  be  radio  ex- 
perts, but  we  can  learn  to  read,  intelligently 
and  with  reasonable  comprehension,  papers 
dealing  with  the  technical  progress  on  radio. 

Those  of  you  who  look  at  radio  in  this  light 
will  appreciate  our  good  fortune  in  having  been 
chosen  by  the  executive  committee  of  the 


Radio  Club  of  America  as  the  magazine  to 
publish  the  papers  presented  at  its  meet- 
ings. 

In  the  membership  of  this  club  are  included 
nearly  all  the  best-known  amateurs  in  the 
vicinity  of  New  York.  Not  only  do  the  mem- 
bers themselves  contribute  interesting  and 
valuable  papers  on  the  various  phases  of  radio, 
but  well  known  workers  in  the  field  from  the 
research  laboratories  of  the  large  manufactur- 
ing companies  have  always  appreciated  the 
honor  of  being  invited  to  speak  before  the 
members,  and  have  gladly  done  so.  We  have 
frequently  attended  the  meetings  of  the  Club 
and  have  always  come  away  with  added 
knowledge  and  renewed  enthusiasm  for  the 
radio  game. 

Radio  Broadcast  is  to  be  congratulated  on 
having  been  selected  by  the  Radio  Club  of 
America  for  the  publication  of  its  papers.  We 
believe  that  the  class  of  readers  to  whom 
Radio  Broadcast  appeals  is  such  that  the 
Radio  Club  may  feel  sure  that  its  papers  are 
reaching  an  intelligent  and  appreciative  audi- 
ence. —J.  H.  M. 


AT  CAMP — FOR  THE  TIME   BETWEEN  SUPPER  AND  SLEEP 
The  large  home  set  can  be  taken  over  the  hills  and  far  away,  when  the  family  chariot  does  the  toting 


THE      MONARCH  OF  ALL  HE  SURVEYS,      IN   ETAH,  NORTH  GREENLAND 


In  Touch  with  the  World  from  the 

Arctic 

How  Dr.  Mac  Millan  Came  to  Take  Radio  with  Him  to  the  Far  North.  The 
Question  of  Communication  Through  the  "Auroral  Band."  How  Broadcasts 
from  Civilization  will  Relieve  the  Greatest  Hardship  of  the  Expedition,  and 
How  the  Explorers  will  Flash  Back  Weekly  Code  Messages  to  Civilization 

By  BURNHAM  McLEARY 


WHILE  you  lounge  in  your 
easy  chair  this  winter,  listen- 
ing to  violins  in  some  distant 
city,  give  a  thought  to  the 
brave  ship  Bowdoin,  cap- 
tained by  Donald  B.  MacMillan,  the  Arctic 
explorer;  for  he  and  his  seven  ship-mates  will 
likely  enough  be  listening  to  that  same  orches- 
tra and  perhaps  be  dancing  to  its  music  on  the 
sparkling  ice-fields  of  the  Frozen  North. 

For  radio  is  on  its  way  to  meet  the  Eskimo. 
About  a  month  ago  it  set  out  from  Wiscasset, 
Maine,  ensconced  in  the  forward  end  of  Captain 
MacMillan's  89-foot  schooner  and  bound  for 
the  northernmost  limits  of  Eskimo  Land, 
hardly  three  hundred  miles  from  the  Pole  itself. 

And  while  you  are  picturing  the  pleasures 
which  radio  will  bring  to  these  Arctic  explorers, 


stand  by  and  listen  for  the  signals  of  their  far- 
off  station.  For  under  the  ice-battened  hatches 
of  the  Bowdoin,  there  is  a  wireless  operator, 
Donald  H.  Mix  by  name,  who  hails  from  Bris- 
tol, Connecticut;  and  his  hand  on  the  key  will 
be  flashing  each  week  a  five-hundred  word  story 
of  adventure  (in  a  special  code  prepared  for  the 
purpose  by  the  Government)  to  seventy  of  the 
leading  newspapers  and  magazines  of  America. 
He  will  transmit,  also,  coded  diagrams  of  all 
new  lands  and  harbors  found  and  charted  by 
the  expedition.  Each  message  will  be  signed 
with  the  letters  WNP.  The  full  name  of  the 
sending  station,  happily  christened  by  the 
Government,  is  Wireless  North  Pole. 

It's  a  great  thing  for  radio,  this  adventur- 
ing into  the  land  of  perpetual  stillness,  un- 
doubtedly the  greatest  from  the  standpoint  of 


284 


Radio  Broadcast 


DONALD    H.    MIX,    RADIO    OPERATOR    ON  THE 
PRESENT  EXPEDITION 

He  was  selected  from  a  group  of  many  applicants  to  take 
charge  of  the  Bowdoin  s  communication  with  the  outside 
world.  He  is  21  years  old,  a  graduate  of  the  Bristol  High 
School,  Bristol,  Conn.,  and  an  amateur  operator  of  six 
years'  standing 

popular  appeal  that  has  yet  taken  place ;  and  the 
story  of  how  it  all  came  about  adds  an  interest- 
ing chapter  to  radio  history. 

On  March  21,  1923,  Captain  Donald  B. 
MacMillan,  F.R.G.S.,  was  guest  of  honor  at  a 
dinner  given  by  U.  J.  ("Sport")  Herrmann  at 
the  Hotel  Sherman,  Chicago,  and  attended  by 
prominent  officers  of  the  Naval  Reserve.  At 
this  dinner  Captain  MacMillan  told  of  the  true 
hardships  of  the  Arctic — not  the  cold,  not  the 
lack  of  food,  but  the  awful  solitude,  so  terrible 
indeed  that  men  go  mad  because  of  it.  He  re- 
called one  expedition  in  particular  when  this 
tragic  fate  befell  a  number  of  the  crew  and  the 
only  way  the  remainder  of  the  party  could  get 
back  to  safety  was  to"  shoot  them. 

Seated  next  to  Captain  MacMillan  was  E.  F. 
MacDonald,  Jr.,  radio  fan  and  owner  of  the  pow- 
erful Edgewater  Beach  Broadcasting  Station. 

"Why  in  the  world  don't  you  take  along  a 
radio  receiving  set?"  was  MacDonald's  im- 
mediate question. 

"Haven't  room,"  replied  MacMillan. 


"Great  goodness,  man,"  said  MacDonald, 
"do  you  realize  how  little  space  a  radio  set 
would  take  up — and  don't  you  see  what  it 
would  do?  1  don't  mean  a  radio  equipped  with 
ear-phones,  but  a  set  with  a  big  loud-speaker 
that  could  be  heard  in  all  parts  of  the  ship. 
Why,  at  a  single  stroke  you  would  eliminate, 
by  your  own  testimony,  the  most  terrible  hard- 
ship of  your  entire  voyage.  Your  men  could 
listen  to  the  same  concerts,  the  same  orchestras, 
which  they  would  be  hearing  if  they  were  at 
home,  could  get  all  the  news  of  the  day,  could 
even  receive  direct  messages  from  their  families 
back  in  civilization.  Give  me  space  no  bigger 
than  that" — MacDonald  measured  the  limits 
with  his  two  hands — "and  I'll  not  only  furnish 
the  radio  that  will  do  all  this  but  have  it  in- 
stalled and  let  you  try  it  out." 

"  All  the  space  1  've  got  left,"  said  MacMillan, 
"is  four  cubic  feet.  If  you  can  do  it  in  that, 
go  ahead." 

This  conversation  took  place  in  March. 
Two  months  later  the  idea  of  radio  communica- 
tion had  made  such  appeal  to  the  explorer  that 
he  had  arranged  to  take  with  him  not  only  a 
standard  Zenith  receiving  set  but  also  a  500- 
watt  Zenith  transmitter,  and  had  told  the  car- 
penter to  rip  out  four  bunks  in  the  forward 
end  of  the  forecastle  to  make  room  for  it. 

The  set  selected  was  located  in  the  labora- 
tory on  the  second  floor  of  the  Zenith 
plant  on  the  outskirts  of  Chicago.  The  motor 
generator  was  placed  on  skids  approximately 
eight  feet  from  the  transmitting  unit.  Leads 
were  run  across  the  floor  in  a  temporary  manner 
and  the  set  was  then  ready  for  test.  The 
aerial  consisted  of  4,  wires  No.  22,  7  strand, 
52  feet  long,  an  exact  duplicate  of  the  antenna 
which  was  subsequently  used  on  the  ship. 
One  porcelain  insulator  was  used  at  the  opposite 
end.  The  lead-in  was  composed  of  two  wires 
connected  to  the  outside  wires  and  came  down 
over  the  side  of  the  building  spaced  five  feet 
away,  and  in  through  the  top  of  a  window 
through  a  formica  tube,  to  the  set,  the  total 
length  of  the  lead-in  being  approximately 
thirty-eight  feet.  The  free  end  of  the  aerial 
was  supported  on  top  of  an  electric  sign  approx- 
imately twenty-five  feet  above  the  roof  of  the 
building.  The  opposite  end  was  supported 
by  a  long  wire  attached  to  the  flagstaff  which 
is  located  in  the  center  of  the  front  of  the 
building  and  was  approximately  fourteen  feet 
above  the  roof.  All  rheostats  and  controls  for 
the  motor  generator  were  temporarily  bolted 


In  Touch  with  the  World  from  the  Arctic 


285 


to  the  floor  in  order  to  save  time  in  the  installa- 
tion for  trial  purposes. 

When  the  test  was  started  at  10:30  p.m.,  the 
operators  immediately  started  to  get  in  touch 
with  amateur  station  iAW.  However,  iAW 
did  not  find  the  wavelength  until  1 130  in  the 
morning  when  communication  was  established 
through  the  means  of  a  relayed  message  from 
3JJ.  Immediately  afterward,  Hartford 
switched  their  wavelength  and  caught  the  test- 
ing station  and  worked  for  approximately  1^ 
hours  with  the  ease  of  being  in  the  same  town. 
At  the  time  the  lower  wavelength  (220  meters) 
was  used,  the  radiation  was  3!  amperes,  and 
on  310  meters  5  amperes.  Under  full  load,  the 
machine  delivered  5!  amperes  into  the  antenna 
on  220  meters,  and  6|  amperes  on  310  meters. 

The  tV  K.  W.  motor  generator  was  driven 
by  storage  batteries  of  32  volts,  each  an  exact 
duplicate  of  conditions  on  board  the  Bowdoin. 
Two  50-watt  power  tubes  were  used.  During 
the  test  the  following  stations  were  worked: 
1  AW,  Hartford,  Conn.;  8Q,  Freeport,  Pa.; 
3  J  J ,  Washington,  D.  C;  6KA,  Los  Angeles, 
Calif. ;  9BXA,  Denver,  Colo. ;  8AWT,  Syracuse, 
N.  Y.;  9ZT,  Minneapolis,  Minn,  (daylight); 
9CWB,  Columbia,  Mo. 


Meanwhile,  the  adventure  had  so  appealed 
to  Mac  Donald  that  the  explorer  invited  him  to 
go  part  way  with  him  and  the  invitation  was 
accepted;  so  that  even  while  you  read  this 
article,  MacMillan  and  MacDonald  are  headed 
toward  the  North  Pole.  The  latter,  however, 
plans  to  end  his  northward  journey  at  the 
Eskimo  village  of  Hopedale.  Labrador,  the 
farthest  point  from  which  he  can  get  a  mailboat 
back  before  ice  closes  navigation  for  the  winter. 

Incidentally,  Mr.  MacDonald  will  return  to 
the  United  States  with  information  of  real 
importance  to  the  success  of  the  expedition,  for 
his  personal  contact  with  the  crew  will  have 
shown  him  exactly  what  kind  of  radio  pro- 
gram most  appeals  to  the  men  and  will  enable 
him  to  put  on  just  such  a  program  once  a  week 
at  the  Edgewater  Beach  Broadcasting  Station 
in  Chicago. 

The  selection  of  the  operator  to  accompany 
radio  on  its  first  adventure  in  the  Arctic,  forms 
a  story  in  itself.  Strangely  enough,  it  is  not 
physique  and  ability  that  are  the  most  impor- 
tant qualifications  for  success  in  the  Arctic, 
but  personality — the  faculty  for  making  one- 
self congenial  in  the  close  quarters  of  an  ice- 
bound ship.    In  the  search  for  the  right  man, 


THE  CREW  OF  THE      BOWDOIN      ON  HER   I92I-22  CRUISE 


286 


Radio  Broadcast 


Hiram  Percy  Maxim,  President  of  the  Amer- 
ican Radio  Relay  League,  was  appealed  to,  and 
his  aid  was  readily  enlisted.  Mr.  Maxim  sent 
out  a  call  for  volunteers.  Hundreds  responded. 
From  this  group,  five  were  picked  as  candidates, 
the  final  choice  being  made  by  Captain  Mac- 
Millan. 

WILL  RADIO   PENETRATE  THE  AURORAL  BAND? 

WITH  a  single  powerful  radio  station  send- 
ing messages  from  Farthest  North, 
opportunity  will  be  afforded  for  studying  cer- 
tain phases  of  radio  transmission  in  a  way  that 
has  never  before  been  possible.  For  example, 
there  is  a  period  of  141  days  during  which  a 
message  sent  at  midnight  must  traverse  hun- 
dreds of  miles  of  sunlight  before  it  reaches 
darkness.  How  will  this  unusual  condition 
affect  the  reception  of  the  message? 

Again,  a  request  will  be  issued  to  all  members 
of  the  American  Radio  Relay  League  to  stand 
by  on  a  certain  evening  of  each  week  and  tune 
in  for  Station  WNP.  What  portions  of  the 
American  continent  will  receive  these  messages? 
Where  will  they  come  through  clearest?  If  a 
line  be  drawn  on  the  map  through  the  stations 
that  succeed  in  picking  them  up,  what  sort 
of  an  arc — if  it  be  an  arc — will  that  line  de- 
scribe? Of  especial  significance  is  this  latter 
question,  for  the  reason  that  never  before  has 


THE      BOWDOIN      FROZEN   IN   FOR  THE  WINTER 
Note  the  snow  igloos  built  on  the  deck  of  the 
ship,  covering  the  hatches  to  retain  the  warmth 


a  scientific  attempt  been  made  to  transmit 
wireless  messages  through  the  "auroral  band" 
which  encircles  the  North  Pole,  and  which,  it  is 
believed,  will  act  as  a  powerful  deterrent.  In 
this  connection  it  is  hoped  that  these  experi- 
ments will  shed  new  light  of  a  purely  scientific 
nature  upon  that  great  mystery  of  the  heavens, 
the  Aurora  Borealis. 

Of  the  nature  of  the  news  that  will  be  flashed 
to  us  from  out  the  Arctic,  we  may  gain  some 
inkling  from  the  talks  which  Captain  Mac- 
Millan  has  given  in  recent  months.  He  tells, 
for  example,  of  the  marvelous  Arctic  summer, 
when  the  weather  is  mild  and  emerald  fields 
are  agleam  with  myriads  of  little  twinkling 
flowers.  He  tells,  also  of  vast  mineral  deposits 
— a  twenty-foot  vein  of  coal,  for  instance,  ut- 
terly exposed  and  waiting  only  for  the  great 
airships  of  the  future.  Doubtless,  too,  he  will 
have  interesting  reports  to  make  of  the  glaciers 
of  the  Far  North,  now  known  to  be  advancing 
rather  than  receding,  and  believed  by  many 
to  foreshadow  for  this  thriving  continent  of 
ours,  a  return  engagement  for  the  Age  of  Ice. 

AN  APPRECIATION  OF  THE  ESKIMO 

MOST  interesting  of  all,  however,  will  be 
his  studies  of  the  Eskimo — in  many  ways 
the  only  remaining  specimen  to  whom  human- 
ity can  point  with  pride !  Devoted  to  his  wife  or 
wives,  kind  to  his  children, 
reverent  always  toward  his 
elders,  ready  always  to 
bring  up  the  orphan  as  his 
own,  the  Eskimo  is  so  free 
from  guile  that  he  may 
well  thank  his  lucky  stars 
that  he  has  no  money,  for 
the  white  man  would  surely 
go  after  it. 

Very  naive  is  the  Es- 
kimo. Shown  a  telephone 
set  by  Captain  MacMillan, 
one  of  them  jabbered  into 
one  end  of  it,  just  as  he  had 
seen  the  white  man  do  and 
then  ran  as  fast  as  he  could 
to  the  other  end,  to  see  if 
he  could  hear  his  own  voice 
coming  through.  Failing  in 
that,  he  cut  the  wire,  puz- 
zled over  it  for  a  while,  and 
then  averred  that  the  whole 
business  was  impossible  as 
the  wire  had  no  hole  in  it! 


In  Touch  with  the  World  from  the  Arctic 


287 


Shown,  in  motion  pictures,  the  traffic  on 
Fifth  Avenue,  he  exclaimed,  "Oh,  see  the  dog 
sleds  that  move  without  dogs. 

Naive,  indeed,  the  Eskimo,  but  a  rather 
good  sort,  for  all  that — and  he  doesn't  have 
such  a  bad  time  of  it,  either,  according  to 
MacMillan. 

If  an  Eskimo  baby  lives  five  days,  it  is  almost 
certain  to  be  good  for  sixty  years — unless  it 
falls  through  the  ice,  or  gets  killed  by  a  bear 
or  a  walrus.  Except  for  heart  disease  and 
rheumatism,  sickness  in  the  Arctic  is  practically 
unknown.  No  good  Eskimo  would  ever  think 
of  having  such  a  thing  as  a  "cold." 

Time,  too,  is  practically  unknown  to  the 
Eskimo.  He  keeps  no  calendar,  has  no  weeks 
or  months  or  years.  No  Eskimo  woman  knows 
her  age. 

Although  the  Eskimo  is  deeply  religious,  he 
would  never  think  of  praying  to  God  for  help, 
because  he  holds  that  it  is  not  necessary; 
God  is  his  friend.  His  only  prayers  are  to 
evil  spirits,  begging  them  to  let  him  alone. 
He  is  sure  of  a  future  life;  to  his  mind  no  one 
with  any  sense  would  question  it.  Some  day 
he  will  go  to  heaven,  a  place  where  it's  warmer, 
and  the  hunting's  good. 

What  will  the  Eskimo  say  when  he  listens  to 
the  radio?  Something  about  spirits,  you  can  be 
mighty  sure;  for  the  Eskimo's  explanation  of 
motion  pictures,  which  Captain  MacMillan  in- 
troduced him  to  last  year,  was,  in  effect,  that  the 
white  man  had  cleverly  conjured  up  the  spirits 
of  people  in  distant  lands  and  put  them  through 
their  tricks!  Doubtless  he  will  say  now  that 
the  white  man  has  found  out  a  way  to  make 
those  "spirits"  talk  and  sing! 

FOURTEEN  MONTHS — OR   FOUR  YEARS? 

HOW  many  months  shall  we  be  privileged 
to. entertain  our  guests  in  the  Arctic  and 
how  long  will  they  be  able  to  send  us  instal- 
ments of  life  in  the  great  white  solitudes? 

Fourteen  months,  if  all  goes  well — but  one 
never  knows. 

In  the  year  19 13,  for  instance,  Captain  Mac- 
Millan headed  an  expedition  to  "Crocker 
Land,"  which  Peary  reported  having  seen  on 
his  successful  dash  to  the  Pole  in  1908.  Inci- 
dentally, Captain  MacMillan,  who  up  to  that 
time  had  been  a  professor  at  Bowdoin  College, 
his  Alma  Mater,  accompanied  Peary  on  his 
earlier  expedition,  being  third  in  relief  when 
the  final  dash  was  made.  On  this  "  Crocker 
Land"  Expedition  MacMillan  journeyed  300 


HAPPY  LAUGHING  AL-NING-WA  OF  THE  SMITH 

SOUND  TRIBE 
Eskimos  do  not  keep  a  calendar,  and  no  Eskimo  woman 
knows  her  age.    But  that  is  the  least  of  Al-ning-wa's 
worries 


miles  across  a  field  of  solid  ice  to  a  point  100 
miles  beyond  the  supposed  location  of  "  Crocker 
Land."  It  was  nowhere  to  be  seen.  He  then 
turned  back  and  ascended  the  exact  elevation 
from  which  Commander  Peary  had  sighted 
'  Crocker  Land,"  and  there,  at  a  distance  of 
100  miles,  he  beheld  this  imaginary  country — 
rugged  hills  and  wooded  stretches,  a  perpetual  and 
permanent  mirage  ! 

In  1913,  as  I  said,  Captain  MacMillan  set 
out  on  this  expedition  to  be  gone  only  fourteen 
months.  Four  years  later  the  ice  of  the  Arctic 
gave  up  a  ship,  and  a  band  of  weary  explorers 
made  their  way  back  to  "civilization,"  there  to 
learn  for  the  first  time  that  practically  the  en- 
tire world  was  at  war! 

Great  changes  have  come  about  since  then. 
Radio  may  not  have  made  the  whole  world 
kin — but  at  least  it  has  placed  its  people  all  on 
speaking  terms. 

War  smolders,  and  at  present  writing,  the 
only  terrible  thing  that  impends  is  another 
presidential  contest.  This  time,  however,  the 
men  of  the  Bowdoin — happily  enough — will  not 


288 


Radio  Broadcast 


IF  AN   ESKIMO  BABY   LIVES  FIVE  DAYS,   HE  IS  GENERALLY  GOOD  FOR  SIXTY  YEARS 
This  most  northern  Eskimo  boy  in  the  world  is  taking  a  sun  bath  twelve 
degrees  from  the  North  Pole  on  the  northern  shores  of  Greenland 

be  kept  in  darkness.    For  better  or  worse,  they  that  they  may  not  indeed  prefer  to  stay  four 

shall  have  the  news — and  no  man  quicker  than  years  and  perchance  find  out  the  answer  to  that 

they!    Thus,  betwixt  wars  and  rumors  of  wars,  question  the  Eskimo  is  always  asking:  "Why 

these  men  up  North  shall  have  full  opportunity  do  you  and  all  the  other  white  people  like  it  better 

to  size  this  old  world  up — and  who  shall  say  to  live  so  far  from  our  home  ?" 

A  Dry-Cell  Tube  Loop  Set  for  Local 

Reception 

By  ALEX  V.  POLSON,  E.  E. 


A    l^~"^HE  receiving  set  here  described  is 
one  which  was  built  after  a  few  weeks' 
experimenting  with  loop  aerial  sets, 
and  it  is  primarily  designed  for  re- 
JL     ception  from  broadcasting  stations 
that  are  not  over  a  hundred  miles  away. 

This  set  has  operated  satisfactorily,  signals 
being  clear  and  loud,  while  it  was  being  carried 
around  the  house.  As  the  detector  tube  used 
is  a  i§-volt  tube,  the  set  may  be  made  very 
compact  and  may  therefore  be  used  as  a  port- 
able outfit  which  will  prove  convenient  where 
a  ground  connection  cannot  easily  be  made. 


A  feature  of  this  set  that  is  a  little  unusual 
is  the  double  loop  aerial,  one  loop  being  used  z.-^ 
a  regular  loop  aerial  and  the  other  being  used  as 
a  tickler  coil.  The  diagonals  for  the  frame  con- 
sist of  two  pieces  of  dry  wood  2\  x  §  x  18  inches, 
mortised  at  the  centre  and  mounted  as  shown 
in  the  accompanying  diagram  (Fig.  i).  Two 
sets  of  binding  posts  are  mounted  on  the  face 
of  the  frame  as  shown.  The  loop  aerial  proper 
consists  of  i  5  turns  of  No.  20  D.  C.  C.  magnet 
wire  spaced  one  eighth  of  an  inch  apart  and 
held  in  place  by  saw  cuts  made  in  the  ends  of 
the  diagonals.    The  ends  of  the  wire  should 


A  Dry-Cell  Tube  Loop  Set  for  Local  Reception 


be  connected  to  two  of  the  binding  posts. 
The  tickler  loop  consists  of  14  turns 
of  No.  20  D.  C.  C.  magnet  wire  spaced 
one  quarter  of  an  inch  apart  and  held  in 
place  on  the  face  of  the  frame  by  small 
brads.  The  ends  of  this  coil  are  con- 
nected to  the  other  two  binding  posts. 

The  inductance  coil  shown  consists 
of  60  turns  of  No.  24  D.  C.  C.  magnet 
wire  wound  on  a  cardboard  tube  4 
inches  in  diameter  and  inches  long. 
Taps  are  taken  off  at  every  tenth  turn. 
The  variable  condenser  is  an  1  i-or  23- 
plate  one,  with  a  vernier  for  best  re- 
sults. In  mounting  the  condenser  and 
inductance  it  was  found  that  consider- 
able space  could  be  saved  by  putting 
the  condenser  inside  the  inductance  tube. 
The  rheostat  should  preferably  be  one 
with  a  vernier,  as  very  close  regulation 
of  the  filament  temperature  is  advisable 
with  the  peanut  or  other  ij-volt  tubes. 
The  grid  condenser  may  be  of  either 
.0005  or  .00025  mfd.  and  should  be  used 
in  conjunction  with  a  variable  grid  leak. 
The  phone  condenser  may  have  a  capac- 
ity of  .001  or  .002  mfd.  The  panel  used 
by  the  writer  is  of  mahogany,  one  quar- 
ter of  an  inch  thick,  but  any  one  of  the  sev- 
eral radio  panel  materials  may  be  used  satis- 
factorily.   Tin  foil  was  stuck  on  the  rear  of  the 


OUTSIDE.     LOOT      IS  TURMS 


panel  and  con- 
nected to  the  nega- 
tive side  of  the  B 
battery  to  cut  out 
body  capacity  ef- 
fects. Care  should 
be  taken  that  the 
tin  foil  does  not 
touch  any  of  the 
metallic  parts  such 
as  binding  posts  or 
contact  points  as 


fig.  2 

The  hook-up  which  Mr. 
Poison  uses  for  loop  re- 
ception on  one  tube 


this  may  short  circuit  some  of  the  apparatus. 
About  eighteen  or  twenty  will  probably  be  the 
best  B  battery  voltage  to  use. 

To  operate  the  set,  it  is 
only  necessary  to  point  the 
loop  so  that  its  edge  points 
toward  the  broadcasting  sta- 
tion, turn  on  the  filament,  set 
the  inductance  switch  to 
about  50  turns  and  vary  the 
condenser  until  signals  or  a 
whistling  sound  .  is  heard. 
Further  adjustment  of  the 
rheostat  and  vernier  con- 
denser will  then  clear  up  and 
binding  bring  the  signals  in  at  their 
^51^  best.  If  it  is  impossible  to 
get  signals  at  all,  the  tickler 
should  be  reversed  at  the 
binding  posts,  as  the  tickler 
must  be  connected  in  the 
proper  direction.  If  the 
ground  connection  shown  by 
the  dotted  lines  (Fig.  2.)  is 
used  in  addition  to  the  loop, 
signals  will  be  much  improved 
in  intensity. 


JUNK  WORTH  A  MILLION  ! 

With  this  very  equipment,  Edwin  H.  Armstrong  discovered  regeneration — the  receiv- 
ing system  that  revolutionized  radio  reception  and  made  the  inventor  famous 


Eighteen  Years  of  Amateur 

Radio 


The  Days  When  Hams  Could  Send  on  Any  Wave.    The  "Junior  Wireless 
Club  Limited,"  Which,  in  1911,  Became  the  "Radio  Club  of  America." 
Pioneer  Experiments  and  Inventions.    Early  Measures  to  Reduce 
Interference.     Recent   Activities   Sponsored    by   the    Radio  Club 

By  GEORGE  E.  BURGHARD 

President  of  the  Radio  Club  of  America 

It  is  with  pleasure  that  we  present  this  paper  on  amateur  radio,  prepared  by  one  of  the  foremost  Ameri- 
can amateurs.  This  paper  has  just  been  read  before  the  Radio  Club  of  America  at  the  close  of  a  successful 
season  of  lectures. 

We  feel  sure  that  the  readers  of  Radio  Broadcast  will  be  glad  to  learn  that  the  Radio  Club  of  America 
has  chosen  our  magazine  for  the  exclusive  publication  of  its  papers,  and  we  wish  to  express  our  appreciation 
of  the  compliment  paid  us. 

Such  solons  as  Professor  M.  I.  Pupin,  Professor  L.  A.  Hazeltine,  Professor  J.  H.  Morecroft,  E.  H.  Arm- 
strong, W.  C.  White  and  many  others,  present  to  this  Club  papers  of  importance,  in  which  we  feel  sure  that 
you  will  find  great  interest. 

The  second  of  these  papers,  which  will  appear  in  our  September  issue,  deals  with  the  latest  of  all  the  vacuum 
tubes — those  employing  thoriated  filaments — and  is  the  work  of  Mr.  W.  C.  White,  of  the  General  Electric 
Company,  who  helped  develop  the  tubes. — The  Editor. 


Eighteen  Years  of  Amateur  Radio 


291 


IN  AN  attempt  to  create  a  precedent  which 
it  is  earnestly  hoped  will  be  followed  as 
long  as  the  Radio  Club  of  America  exists, 
this  paper  is  presented  as  the  first  of  a 
series  of  papers  by  the  Chief  Executive, 
describing  the  activities  of  the  organization 
and  its  members  during  the  last  twelve 
months.  As  this  is  the  first  of  the  series, 
however,  it  may  be  well  to  review  the  achieve- 
ments of  the  Club  from  the  time  of  its  incep- 
tion, and  even  the  work  of  its  members  before 
the  idea  of  organization  had  materialized. 
In  this  way  it  is  possible  to  gain  a  good  idea  of 
the  beginnings  of  amateur  radio  as  well  as  the 
early  strivings  of  the  art  in  general,  since  the 
Club  numbers  among  its  members  many  of 
the  radio  pioneers. 

It  is  the  earnest  hope  of  the  writer  that  the 
aforementioned  precedent  will  be  followed 
closely  and  that  each  succeeding  President  of 
the  Club  will  prepare  and  read  a  paper  cover- 
ing its  accomplishments  during  his  period  of 
office.  Thus,  an  accurate  record  of  Radio 
Progress  can  be  maintained  and  should  prove 
of  considerable  interest  and  value  both  to  the 
present  and  future  radio  generations. 


The  early  days  of  radio  were  indeed  days  of 
darkness  and  pioneering — days  when  traffic 
had  to  be  handled  with  a  coherer  and  a  straight 
gap  spark  transmitter.  This  meant  that  the 
personnel  was  really  the  most  important 
factor,  and  operators  were  developed  who 
could  copy  coherent  messages  under  conditions 
when  the  average  mortal  could  distinguish 
nothing  but  crashes  and  noises.  These  men, 
who  learned  their  lessons  in  a  very  hard 
school,  learned  them  well  and  are  in  many 
cases  the  prime  factors  in  radio  to-day. 

At  the  same  time  that  the  commercial 
companies  were  making  their  initial  stand,  the 
fascination  of  sending  messages  through  space 
without  wires  began  to  take  hold  of  the  younger 
generation,  and  we  have  the  beginning  of  ama- 
teur radio,  about  1905.  Of  course,  there  had 
been  private  experimenters  prior  to  this,  but 
the  real  radio  amateur  had  his  beginning  in  the 
end  of  1904  to  1905.  Small  boys  began  to  in- 
veigle their  parents  into  giving  them  money 
with  which  to  buy  wire  and  other  material  to 
build  their  own  sets  in  imitation  of  those  used 
by  the  commercial  companies.  Their  efforts 
were  gallant  indeed,  for  there  were  no  books 


BACK  IN    191O,  WHEN  THE  WRITER  WAS  AN  ARDENT  FAN 
George  Burghard  operating  one  of  his  first  transmitters,  located  at  1  East  93rd  Street,  New  York  City 


292 


Radio  Broadcast 


THE  RECEIVER 
AT  2  PM 
Not  the  time  of  day  but 
the  call  letters  of  the  sta- 
tion owned  by  John 
Grinan  and  Adolph  Fa- 
raon.  Amplifiers  were  al- 
most unknown  when  this 
station,  in  New  York, 
heard  the  "Coast,"  and 
the  two  tubes  were  both 
used  as  detectors,  with 

individual  controls 


to  guide  them.  But  the  results  proved  successful 
in  some  cases,  where  the  frequency  of  the  transmit- 
ter happened  by  chance  to  be  within  the  range  of 
the  receiver,  or  someone  had  gained  expert  knowl- 
edge from  the  operators  at  Manhattan  Beach  or  the 
Waldorf  Astoria  where  the  main  commercial  land 
stations  were  located.  With  the  crude  apparatus 
and  the  embryo  knowledge  available,  it  was  really 
remarkable  that  those  boys  could  communicate  at 
all,  but  almost  any  night  one  could  hear  messages 
being  exchanged  between  stations  in  New  York  City 
covering  distances  of  approximately  a  mile  or  two. 

At  that  time  there  were  perhaps  a  handful  of  these 
amateurs  in  New  York  City,  but  they  grew  rapidly  in 
numbers  and  by  1909  they  had  already  organized  into 
the  "Junior  Wireless  Club  Limited."  This  organiza- 
tion, which  was  really  the  first  of  its  kind,  held  regular 
monthly  meetings  at  the  Hotel  Ansonia  where  the 
President,  W.  E.  D.  Stokes,  Jr.,  was  living  at  that 
time.  The  original  membership  consisted  of  eleven 
men  who,  it  may  be  said,  were  the  founders  and 
charter  members  of  the  Radio  Club  of  America: 
W.  E.  D.  Stokes,  Jr.,  George  Eltz,  Jr.,  Faitoute 
Munn,  Ernest  Amy,  Frank  King,  Graham  Lowe, 
Frank  Whitehouse,  Lyman  Butler,  and  George  E. 
Burghard.  These  young  boys  were  the  leaders  of 
amateur  radio  at  that  time  and  soon  drew  all  the 
live  operators  into  their  organization. 


2   PM  S  TRANSMITTER 

This  was  the  first  amateur  station 
to  transmit  across  the  continent 


In  1 910,  under  the  auspices  of  the  Radio 
Club,  the  father  of  all  radio  call-books  was 
born.  It  consisted  of  a  single  mimeo- 
graphed sheet  with  some  thirty-odd  names. 
Later  this  was  increased  to  two  sheets, 
then  four  blue  printed  sheets,  and  so  on  un- 
til the  task  became  too  ponderous  and  had 
to  be  undertaken  by  real  publishers. 


Eighteen  Years  of  Amateur  Radio 


293 


The  following  list  is  copied  from  the  original 
typewritten  sheet.  (The  question  marks  indi- 
cate names  or  addresses  that  could  not  be 
made  out) : 

BB  Max  Bamberger,  16  W.  70th  St. 

GX  Harlow  Hardinge,  331  W.  101  st  St. 

9  ?        Melly,  328  W.  96th  St. 

HB  Doctor  Besser,  SE  Cor.  Bdwy  &  144th  St- 

DR  Dr.  W.  G.  Hudson,  312  VV.  109th  St. 

VD  Randolph  Runyon,  Yonkers,  N.  Y. 

C  George  Cannon,  Mount  Vernon 

SK  G.  Skinner,  Mount  Vernon 

GE  George  Eltz,     ?     W.  47th  St. 

WR  W.  Russell,  242  W.  104th  St. 

VN  Irving  Vermilya,  Mount  Vernon 

BB  Louis  Schulman,     ?    W.  106th  St. 

K9  Francis  C.  Knochel,     ?    W.  1 59th  St. 

YN  G.  Popper,  763  Beck  St.,  Bronx 

PC  Percy  Corwing,  5  West  107th  St. 

DG  Harry  Johnson,  Patterson,  N.  J. 

1Y  Fred  Tracy,  4  W.  129th  St. 

BF  Brace  Fitler,     ?    W.  129th  St. 

RG  Alfred  Roebling,  Far  Rockaway 

UH  Ernest  Hubner,  1657  First  Ave. 

WL  Walter  Lemon,  94th  St.  &  Bdwy. 

GW  G.  Bartlett,  8  W.  108th  St. 

EA  Ernest  Amy,  48  W.  70th  St. 

DX  Elmer  Ayers,  235  W.  103rd  St. 

SG  Vincent  Lamarche,  70  W.  46th  St. 

CH  John  Myers.  315  W.  40th  St. 

GH  Doctor  Goldhorn,  Mount  Vernon 

KH  K.  Harries  (2) 

QW  C.  D.  Winslow,  1985  Amsterdam  Ave. 

PX  P.  H.  Boucheron,  303  E.  48th  St. 

JB  Louis  Bahr,  1929  Amsterdam  Ave. 

JF  John  Farrington,  467  W.  139th  St. 

TR  George  Post,  292  Riverside  Drive 

CP  Clarence  Pfeiffer,  Ridgewood,  N.  J. 

AH  Arthur  Herbert,  138  W.  123rd  St. 

CS  Charles  Schaffer,  459  E.  147th  St. 

YP  Fred  Parsons,  764  Beck  St.,  Bronx 

BO  Massey  Wireless  Co.,  170th  St.  &  Jerome  Ave. 

FK  Frank  King,  326  West  107th  St. 

In  191 1  the  membership  had  increased 
considerably,  and  the  name  was  changed  to 
The  Radio  Club  of  America,  which  is  the 
name  it  bears  to-day.  By  this  time  books  and 
other  literature  on  various  radio  topics  began 
to  appear,  so  that  the  knowledge  of  the  Club 
members  was  greatly  increased  and  papers 
were  delivered  at  their  monthly  meetings, 
which  were  held  at  the  home  of  Frank  King, 
who  was  elected  first  President  of  the  new 
organization.  The  first  papers  consisted  of 
short  talks  describing  the  various  stations 
operated  by  the  members,  and  various  they 
were  indeed.  It  is  almost  useless  to  attempt 
descriptions,  but  perhaps  the  accompanying 
photographs  will  serve  to  give  an  idea  of  the 
types  of  apparatus  used  and  the  great  handicap 
under  which  communication  was  maintained 
in  those  days  when  it  was  considered  a  great 
event  to  work  Yonkers  from  New  York  City 
direct.  But  still,  even  this  was  a  great  advance 
over  the  old  coherer  days.    Now  there  were 


crystal  detectors,  microphone  detectors,  and 
even  electrolytic  detectors.  Boys  were  busily 
engaged  in  breaking  up  chunks  of  rock  in  an 
attempt  to  find  a  good  piece  of  carborundum, 
copper  pyrites,  or  zincite,  or  groveling  on 
hands  and  knees  diligently  searching  the  floor 
for  the  missing  piece  of  Wollaston  wire  which 
was  always  diminutive  and  hard  to  find. 
These  new  detectors  together  with  the  advance 
in  knowledge  enabled  the  amateur  operator  to 
establish  quite  reliable  communication  within 
the  city  limits  and  occasionally  a  superhuman 
feat  such  as  working  Yonkers,  a  distance  of 
about  fifteen  miles  was  accomplished,  but  for 
some  unknown  reason  it  was  impossible  to  get 
any  signal  across  to  Brooklyn. 

And  yet  the  strivings  of  this  handful  of 
boys  led  to  great  things  and  great  things  were 
discussed  at  the  meetings.  No  one  thought  of 
the  far-reaching  possibilities  of  the  Hudson 
coated  filament  at  the  time  when  Dr.  Hudson 
delivered  his  paper  describing  this  very  useful 
invention  over  the  pool  table  at  Frank  King's 
house  in  191 3,  nor  were  the  stupendous  results 
of  the  regenerative  circuit  in  any  way  apparent 
at  the  time  E.  H.  Armstrong  told  us  all  about 
it  at  one  of  the  meetings  in  1915.  Who  could 
have  dreamed  of  the  extent  to  which  radio 
telephony  would  grow  when,  in  191 1,  George 
Eltz  and  Frank  King  constructed  and  oper- 
ated an  arc  telephone  transmitter  at  107th 
Street  and  actually  played  music  for  the  benefit 
of  the  fleet  in  the  Hudson  River  when  the 
alcohol  didn't  explode  in  the  arc  chamber 
and  cause  a  violent  break-down  without 
any  time  for  an  apologetic  "one  moment, 
please."  This  may  be  said  to  constitute  the 
first  real  broadcasting  station  ever  operated 
with  any  degree  of  success. 

By  this  time  the  three-electrode  vacuum 
tube  had  appeared  on  the  scene.  Audions 
they  were  called,  and  cost  $5.00  a  piece,  but 
every  amateur  had  to  have  one.  So  down  to 
the  Metropolitan  Tower  he  would  go,  up  to 
the  DeForest  Radio  Company's  laboratory, 
leave  his  five  and  go  home  with  his  most  pre- 
cious possession.  Of  course  the  number  of 
identical  new  circuits  and  inventions  developed 
by  these  boys  was  great,  but  nevertheless 
communication  was  greatly  benefited  and  mes- 
sages could  be  sent  and  received  over  distances 
of  approximately  50  miles,  quite  regularly. 
This  marked  a  great  advance  in  amateur  radio 

During  these  early  days,  the  activities  of 
these   amateur  experimenters   aroused  con- 


294 


Radio  Broadcast 


siderable  interest,  and  it  was  not  long  before  the 
Government  began  wondering  what  it  could 
do  to  control  these  newcomers.  The  idea  of 
restricting  the  free  air  had  never  occurred  to 
any  one  before.  The  result  was  a  bill  in- 
troduced by  Senator  Depew  in  1910,  prohibit- 
ing amateur  radio  communication.  The  then 
members  of  the  Junior  Wireless  Club  quickly 
rallied,  and  a  committee  was  sent  to  Washing- 
ton to  plead*  the  cause  of  the  amateur  before 
Congress.  The  plan  was  successful  and  the 
bill  was  lost.  In  191 2  the  Alexander  Wireless 
Bill  was  introduced,  which  purported 
to  do  all  that  the  Depew  Bill  had 
failed  to  accomplish  and  even  more. 
The  Club  also  took  action  on  this 
bill,  killed  it  in  Committee,  and 
later,  through  the  concerted  action 
of  its  members  in  the  service  after 
the  Armistice,  definitely  settled  the 
matter. 

In  1 91 2,  one  of  the  most  illustrious  members 
of  the  Radio  Club,  E.  H.  Armstrong,  developed 
the  feed-back  circuit  which  has  made  possible 
the  broadcasting  of  to-day.  This,  of  course,  did 
wonders  for  the  amateur.  All  kinds  of  tuning 
coils  and  couplers  were  put  into  use,  and  sets 
were  operated  to  the  Nth  degree  of  regeneration 
until  finally  real  communication  with  the 
Western  amateur  stations  was  established  and 
amateur  radio  came  into  its  own. 

This  also  opened  another  field  to  the  amateur, 
namely  transatlantic  reception.  Perhaps  the 
first  attempts  at  hearing  the  stations  of  Europe 
were  made  by  Paul  Godley,  Harry  Sadenwater, 
and  Louis  Pacent,  who  in  1914  strung  an 
antenna  from  the  Palisades  on  the  Hudson 
River  and  with  a  specially  constructed  receiver 
listened  patiently  for  what  they  had  never 
heard  before.  Little  did  Godley  think  at  that 
time  that  some  years  later  he  would  be  listening 
just  as  attentively,  under  different  conditions, 
in  a  tent  in  Scotland,  for  the  signals  of  his 
brother  amateurs  in  America. 

In  those  days,  of  course,  there  were  no  li- 
censes and  no  regulations  for  amateurs.  Every- 
one used  whatever  wavelength  he  happened  to 
hit  upon,  and  the  great  difficulty  of  getting  a 
wave  meter  left  that  unknown  in  most  cases. 
The  only  way  to  find  out  whether  the  set  was  in 
tune  was  by  inserting  a  carbon  filament  lamp 
in  series  with  the  antenna  and  adjusting  the 
helix  [antenna  tuning  inductance]  for  maxi- 
mum brilliancy.  Some  stations  had  aerials 
of  as  many  as  eight  or  ten  wires,  one  to  two 


hundred  feet  long,  and  sparks  gaps  directly 
coupled.  This,  of  course,  could  not  continue, 
so  the  Radio  Club  welcomed  the  new  li- 
cense regulations  and  did  a  great  deal  toward 
assisting  Radio  Inspector  Marriott  'and  later 
Harry  Sadenwater  in  clearing  up  the  mess.  In 
fact,  the  relationship  of  the  Club  with  the 
Department  of  Commerce  has  always  been 
most  friendly.  On  one  occasion  the  two 
organizations  combined  .  to  track  down  an 
amateur  station  in  Brooklyn  with  a  loop 
mounted  on  an  automobile.  The  boy  had  for 
no  apparent  reason  been  sending  out 
distress  calls,  and  after  a  whole  night's 
searching  the  station  was  finally  lo- 
cated and  the  culprit  called  to  ac- 
count. 

This  was  going  a  long  way  toward 
the  right  system  of  cooperation,  es- 
pecially in  those  days  when  the  no- 
tion of  free  air  still  prevailed  and 
it  was  actually  necessary  for  the  operators 
of  one  commercial  station  to  invite  certain 
amateurs  to  go  swimming  at  Coney  Island  so 
that  the  relief  operators  could  handle  their 
traffic  without  interference! 

The  Club  soon  outgrew  its  quarters  at 
Frank  King's  home  in  107th  Street  and  it  was 
not  long  before  the  attendance  at  meetings 
grew  so  large  that  it  became  necessary  to  use 
the  large  lecture  halls  of  Columbia  University 
for  the  monthly  gatherings.  As  the  art  grew 
and  radio  knowledge  was  more  readily  ob- 
tainable, the  character  of  the  papers  also 
changed.  The  small  body  of  amateur  opera- 
tors gradually  changed  to  a  large  scientific 
organization  of  recognized  standing,  before 
which  the  leading  lights  in  the  radio  world 
were  glad  to  deliver  papers  on  their  newest 
discoveries.  But  in  spite  of  these  changes  the 
club  idea  and  spirit  of  comradeship  was  never 
lost,  and  even  to-day  the  Radio  Club  of  America 
is  as  proud  of  its  congenial  club  spirit  as  it  is 
of  its  scientific  standing. 

In  191 5  the  Club  installed  and  operated  a 
transmitting  and  receiving  station  in  the 
Hotel  Ansonia  where  Admiral  Fletcher  had 
made  his  headquarters.  The  station  operated 
by  the  Club  members  handled  all  of  the 
Admiral's  traffic  with  the  fleet  in  the  Hudson 
River.  Several  hundred  messages  were  handled, 
and  President  Wilson  himself  sent  a  message 
from  the  Mayflower  commending  the  good 
work.  The  Navy  League  also  presented  the  Club 
with  a  banner  in  recognition  of  its  services. 


Eighteen  Years  of  Amateur  Radio 


295 


PROFESSOR  PUPIN  AND  THE  DELEGATION  THAT  VISITED   I  BCG  AT  GREENWICH,  CONN. 
The  trip  was  made  with  a  view  to  using  this  station  for  transatlantic  work  on  short  waves.    Professor  Pupin  is 
seated  in  the  centre  of  the  group,  with  George  Burghard  at  his  right,  and  E.  H.  Armstrong  at  Burghard's  right 


A  year  later,  amateur  station  2PM  which  has 
gone  down  in  history  as  one  of  the  most  famous 
of  all  amateur  stations,  owned  and  operated 
by  John  Grinan  and  Adolph  Faraon,  succeeded 
in  breaking  all  records  by  sending  the  first 
transcontinental  relay  message  from  New  York 
to  California.  This  affair  was  not  prearranged 
but  was  accomplished  during  the  ordinary 
transmission  periods  and  the  answer  was 
received  back  in  New  York  in  one  hour  and 
forty  minutes  from  the  time  of  transmission. 
Several  weeks  later  the  same  station  and  the 
same  operators  succeeded  in  getting  signals  to 
California,  a  distance  of  some  2,500  miles  over- 
land, a  feat  which  had  heretofore  been  deemed 
impossible  with  an  input  of  one  kilowatt  on 
amateur  wavelengths. 

Activities  had  to  be  suspended  for  the  next 
few  years,  due  to  the  fact  that  all  the  members 
of  age  enlisted  in  one  branch  of  the  service  or 
another.  The  war  records,  which  have  been 
chronicled  elsewhere,   make  too  lengthy  a 


proposition  for  this  paper.  It  suffices  to  say 
that  practically  all  were  officers  in  radio  capa- 
cities and  in  charge  of  important  operations, 
such  as  radio  aircraft,  radio  schools,  labora- 
tories, field  service,  etc.  Notably,  E.  H. 
Armstrong,  with  the  armies  in  France,  invented 
the  super-heterodyne  receiver  which  aided 
greatly  in  establishing  successful  radio  com- 
munication at  the  front. 

After  the  Armistice  was  signed  and  things 
began  to  assume  a  normal  appearance,  Club 
activities  were  resumed  and  the  first  event  was 
a  get-together  dinner,  held  at  the  Hotel  Ansonia, 
in  honor  of  E.  H.  Armstrong  upon  his  return 
from  France.  Many  prominent  men  were 
among  those  present  and  due  homage  was 
paid  him  for  his  great  work  with  the  Ex- 
peditionary Forces. 

In  1 9 19,  a  successful  flight  was  made  by 
the  Navy  Department  from  Halifax  to  the 
Azores,  in  which  radio  played  an  impor- 
tant part.     Three  planes   were  used  and 


296 


Radio  Broadcast 


of  course  radio  was  a  very  important  part  of 
the  equipment  and  the  operators  had  to  be  of 
sterling  worth.  Lieutenant  Harry  Saden- 
water,  a  Radio  Club  member,  was  chosen  to 
operate  the  set  on  the  NC  1.  Unfortunately, 
this  ship  was  forced  to  the  water  within  twenty 
miles  of  the  Azores  and  it  was  due  to  the 
valiant  efforts  of  Lieutenant  Sadenwater  that 
the  storm-tossed  crew  were  finally  rescued  by  a 
destroyer  which  responded  to  his  calls  after 
some  fifteen  hours  of  gruelling  work. 

When,  in  1921,  the  American  Radio  Relay 
League  instituted  its  amateur  transatlantic 
tests,  the  Radio  Club  of  America  built  a 
special  continuous-wave  transmitting  station 
at  Greenwich,  Conn,  and  succeeded  in  winning 
the  prize  offered  by  Mr.  Burnham,  of  England, 
for  the  best  station  in  the  test.  This  station 
not  only  succeeded  in  transmitting  audible 
signals  to  Paul  Godley,  also  a  member  of  this 
club,  in  Scotland,  but  was  heard  in  Germany, 
Italy,  and  France.  It  also  broke  all  records  by 
sendinga  complete  12-word  message  to  Scotland 
and  later  sent  three  complete  messages  direct 
to  Avalon,  Catalina  Islands,  off  the  coast  of 


California.  These  feats  aroused  such  interest 
in  view  of  the  low  power  and  short  wavelength 
used  (i.  e.,  1  K.  W.,  215  meters),  that  such 
prominent  men  as  Professor  M.  I.  Pupin  of 
Columbia  University  and  David  Sarnoff, 
General  Manager  of  the  Radio  Corporation, 
went  to  Greenwich  to  visit  the  station. 

By  this  time  the  number  of  amateur  stations 
had  increased  to  a  tremendous  extent,  and 
with  broadcasting  just  about  beginning,  com- 
munication was  becoming  almost  impossible. 
The  Radio  Club  investigated  the  situation 
and  found  that  most  of  the  interference  was 
caused  by  spark  and  interrupted  continuous 
wave  transmitters.  It  therefore  undertook  a 
vigorous  campaign  of  advice  and  suggestion, 
through  papers  presented  before  the  member- 
ship, to  educate  the  amateur  in  the  whys  and 
wherefores  of  pure  continuous-wave  transmis- 
sion and  its  many  advantages  over  the  older 
forms.  The  campaign  proved  successful  and  is 
still  in  progress. 

It  was  at  one  of  these  meetings  in  1922  that 
E.  H.  Armstrong  startled  the  radio  fraternity 
by  producing  a  sufficient  volume  of  music 


THIS  IS  FRANK  KING  S  STATION,   FK,  NOW  NOTHING  BUT  A  MEMORY  OF  PAST  GLORY 
Old-timers  will  recognize  several  antiques,  including  a  variable  condenser,  loose  coup- 
ler, crystal  and  electrolytic  detectors,  and  that  king  of  QR.M — the  10-inch  spark  coil 


Eighteen  Years  of  Amateur  Radio 


297 


SCHEMATIC  DIAGRAM  OF  THE  LOUD  SPEAKER  SYSTEM  USED  AT  GRAND  CENTRAL  PALACE 


to  fill  the  large  lecture  hall,  using  his  newly 
invented  super-regenerative  circuit,  a  loop 
aerial  and  only  one  Western  Electric  J  Tube. 
This  performance,  of  course,  had  never  been 
equalled,  and  when  it  is  considered  that  the 
signals  were  coming  from  station  WJZ,  at 
Newark,  N.  J.,  and  that  the  receiving  set  was 
located  in  a  steel  building  with  a  copper  roof 
at  Columbia  University,  it  was  certainly  an 
epoch-making  event. 

In  December  1922,  The  Radio  Exposition 
Company  held  a  large  Radio  Show  at  the 
Grand  Central  Palace,  New  York.  As  every- 
one knows,  if  all  the  exhibitors  at  a  Radio 
Show  are  permitted  to  receive  broadcast 
programs  at  the  same  time,  chaos  would 
result  due  to  heterodyning  between  the  re- 
ceivers themselves.  In  order  to  avoid  this 
difficulty,  the  exposition  directors  decided 
to  permit  only  one  concern  to  do  all  the  re- 
ceiving. This,  of  course,  was  an  unhappy 
thought  since  there  was  no  way  of  deciding 
which  company  this  should  be,  without  causing 
vigorous  protest  from  the  other  exhibitors. 
Finally  it  was  decided  to  choose  a  non-com- 
mercial organization.  The  lot  fell  to  the 
Radio  Club  of  America.  A  special  committee 
was  appointed  and  the  work  begun.  Tests 
were  made  a  week  prior  to  the  opening  of  the 


show  with  various  types  of  antennas  and  finally 
it  was  found  that  even  a  loop  would  pick  up  too 
much  of  the  noises  resulting  from  commutator 
sparking,  circuit  breakers,  and  electric  locomo- 
tive shoes,  from  the  power  houses  in  the  vicinity 
and  the  New  York  Central  tracks  directly 
beneath,  so  that  a  single  wire  about  fifteen  feet 
in  length  had  to  be  used.  The  problem 
proved  to  be  twofold  and  a  great  deal  more 
ponderous  than  was  at  first  anticipated.  First 
there  was  the  matter  of  doing  away  with 
extraneous  noises  so  as  to  deliver  pure  radio 
signals  to  the  power  amplifiers  and  secondly  a 
physical  problem  of  placing  the  loud-speaking 
horns  so  that  there  would  be  no  re-echoes  or 
dead  spots.  The  first  was  solved  after  much 
experimentation  by  the  small  antenna,  a 
600-meter  frequency  trap,  and  a  super-heter- 
odyne receiver.  The  acoustic  problem,  how- 
ever, offered  stubborn  resistance.  Six  loud 
speaker  units  with  four-foot  straight  horns 
were  obtained,  and  the  question  was  how  to 
place  them  so  that  the  sound  would  fill  the 
entire  Grand  Central  Palace  exhibition  hall. 
At  first,  they  were  hung  radially  in  a  cluster 
from  the  ceiling  in  the  centre  of  the  floor  space. 
This  proved  unsuccessful  since  many  re-echoes 
were  produced  from  the  side  walls  and  dead 
spots  resulted  from  large  columns.  Finally, 


298 


Radio  Broadcast 


after  trying  several  other  positions,  it  was 
decided  to  place  the  horns  on  the  balcony 
directly  in  front  of  the  specially  constructed 
booth  which  housed  the  receiving  and  amplify- 
ing apparatus.  It  is  interesting  to  note  that 
all  the  horns  had  to  be  placed  together  because 
any  separation  by  placing  horns  at  various 
points  about  the  hall  produced  out  of  phase 
relationship  and  distortion.  As  it  was,  only 
five  horns  could  be  used,  since  the  sixth  faced  a 
wall  and  produced  a  decided  re-echo  which 
interfered  with  the  speech  to  a 
marked  degree. 

The  receiving  and  amplifying  ap- 
paratus used,  consisted  of  the  small 
antenna  described  before,  a  frequency 
trap  consisting  of  a  coil  and  variable 
condenser,  a  tuned  circuit,  three  stages 
of  radio-frequency  amplification,  a 
super-heterodyne  receiver  with  one  initial 
stage  of  radio-frequency  amplification,  and 
three  stages  of  intermediate-frequency  ampli- 
fication, and  the  usual  oscillator  and  two 
detector  tubes;  one  stage  of  audio-frequency 
amplification  and  then  six  two-stage  audio- 
frequency amplifiers  of  the  push-pull  type, 
connected  in  series  parallel,  each  amplifier 
feeding  one  horn,  the  sixth  horn  being  in  the 
booth  and  acting  as  a  pilot  for  the  operators. 
Some  twenty-nine  tubes  were  used  in  all  and 
each  horn  may  be  said  to  have  had  fourteen 
tubes  connected  to  it.  Of  course,  the  drain 
on  the  batteries  was  great,  but  four  250-ampere- 
hour  6-volt  storage  batteries  supplied  the 
filaments  without  much  trouble,  while  95 
dry  cells  connected  in  series  successfully 
handled  the  plate  supply.  The  diagram  on 
page  297  gives  an  idea  of  the  general  layout  and 
circuits. 

This  system  proved  very  successful  and  in 
spite  of  many  sceptical  opinions  at  the  outset, 
sufficient  volume  was  produced  to  fill  the  hall 
amply,  and  on  the  last  night,  the  signals  from 
WEAF  were  reproduced  with  such  intensity 
that  several  of  the  audience  on  the  main  floor 
were  seen  to  hold  their  hats  in  humorous  indi- 
cation of  their  approval. 

In  1922,  when  Secretary  Hoover  found  it 
necessary  to  call  a  meeting  of  the  radio  in- 
terests before  a  special  committee  of  his 
choosing,  the  Radio  Club  was  represented  on 
the  Committee  by  E.  H.  Armstrong.  Thus 
the  Club  again  as  of  old  took  an  active  part  in 
the  regulation  of  radio  by  Congress.  This 
special  committee  reported  direct  to  Congress 


on  its  findings,  and  did  much  to  help  frame  the 
present  regulations. 

This  brings  the  tale  of  the  activities  of  the 
Radio  Club  up  to  the  present  day.  It  is 
hoped  that  they  may  continue  along  the  same 
lines  for  many  years  to  come  and  that  those 
policies  which  have  been  followed  in  the  past 
and  the  ideals  for  which  the  Club  stands  will 
never  be  forgotten.  The  Radio  Club  of  America 
was  organized  to  propagate  the  art  of  radio  tel- 
egraphy and  telephony  in  all  its  branches,  and 
true  to  this  ideal  it  has  always  lent 
its  aid  to  the  best  of  its  ability  to  all 
phases  of  the  art.  It  originated  as  an 
amateur  organization  with  a  scien- 
tific purpose.  It  fought  for  the  con- 
tinued existence  of  the  amateur  and 
helped  to  educate  him.  It  lent  a 
helping  hand  to  commercial  radio,  by 
research  and  cooperation  wherever  it  could. 
It  gave  all  it  had  to  the  Government  when  it 
was  in  dire  need  of  radio  personnel,  and,  finally, 
when  that  new  element  in  radio  cropped  up — 
the  broadcast  listener — it  gave  him  much 
needed  assistance.  This  organization  belongs 
to  no  one  branch  of  the  radio  art  but  to  all 
branches  and  therefore  its  duty  at  present  must 
necessarily  be  one  of  education.  Through  the 
medium  of  its  papers  and  discussions  as  well 
as  the  individual  efforts  of  its  members,  it  must 
endeavor  to  terminate  the  disastrous  conflict 
which  has  sprung  up  between  the  original  radio 
amateur  or  traffic  amateur  and  the  broadcast 
listener.  Both  classes  must  be  trained  and  as- 
sisted to  become  mutually  beneficial  to  one  an- 
other. The  traffic  man  must  be  shown  how  to 
construct  his  transmitter  so  as  to  create  mini- 
mum interference,  and  the  broadcast  listener 
how  to  operate  his  receiver  at  the  point  of 
maximum  selectivity.  Neither  one  nor  the 
other  can  or  should  be  permitted  to  die  out, 
for  each  has  his  own  particular  value.  The 
broadcast  listener  class  is  composed  of  the 
general  public  whose  pleasure  and  comfort  must 
not  be  interfered  with  at  any  cost,  while  the 
splendid  services  of  the  traffic  amateurs  in  the 
World  War  will  never  be  forgotten  and  surely 
entitle  them  to  an  everlasting  right  of  existence. 
But,  unless  these  two  warring  factions,  can  be 
educated  to  cooperate  and  aid  one  another,  one 
of  the  two  is  doomed;  and  this  task  of  education 
for  the  good  of  the  radio  art  must  now  be  the 
important  work  of  the  Radio  Club  of  America 
as  well  as  all  other  radio  clubs  throughout  the 
United  States. 


BROADCASTING  A  NIGHT  SESSION  OF  A   KANSAS  CITY  COURT 

A  part  of  one  of  Mayor  Cromwell's  "civic  radio  nights."  Judge  Michael 
J.  Kilroy  of  the  North  Side  Court  is  at  the  right  of  the  microphone 

''Selling"  the  Public  on  Better  City 

Government 

How  Mayor  Cromwell's  Civic  Radio  Night  Programs  Bring  Sessions 
of  the  Municipal  Court  Into  the  Homes  of  Kansas  City  Residents 

By  J.  L.  SIMPSON 


COULD  the  average  business  or  pro- 
fessional man  of  Kansas  City,  or 
any  other  full-grown  city  in  the 
United  States,  if  suddenly  called 
upon,  take  over  the  job  of  mayor 
of  the  city?  Even  the  business  man  who  re- 
gards his  job  as  tedious  or  difficult  might  be 
pardoned  for  regarding  such  a  step  as  jumping 
from  the  frying  pan  into  the  fire,  especially 
with  the  horde  of  voters  who  "put  him  over" 
sitting  back  in  an  attitude  of  critical  observa- 
tion, waiting  for  the  first  sign  that  the  new 


chief  executive  of  such  city  may  fail  to  turn 
out  a  full  day's  work,  with  each  and  every 
twenty-four  hours. 

Frank  H.  Cromwell,  who  was  overwhelming- 
ly elected  to  preside  over  the  "  Heart  of  Ameri- 
ca" at  the  last  municipal  election,  recently 
found  himself  in  this  precise  predicament,  and 
didn't  exactly  enjoy  this  sensation.  He  had 
specialized  in  the  butter  and  egg  business  until 
his  election  about  one  year  ago,  and  discovered 
very  shortly  that  he  knew  much  more  about 
the  intricacies  of  dealing  in  those  commodities 


300 


Radio  Broadcast 


than  he  might  reasonably  expect  to  know 
about  his  new  job  for  some  time  to  come. 
Commenting  upon  this  startling  discovery,  he 
said: 

"  I  wasn't  Mayor  long  when  1  found  out  I'd 
have  to  learn  a  lot  of  things  about  the  machinery 
of  city  government  I'd  never  dreamed  of. 
I  was  up  against  the  proposition  of  learning 
a  new  business — for  the  operation  of  a  city 
government  is  a  business  of  the  most  intricate 
sort. " 

The  first  morning  Mayor  Cromwell  sat  in  his 
new  office,  he  made  the  discovery  that  he  was 
boss  of  twenty-three 
city  departments, 
each  separate  and  dis- 
tinct from  the  others, 
just  as  in  any  great 
corporation. 

Each  department, 
he  found,  had  a  cer- 
tain duty  to  perform 


the  public,  and  must 
give  satisfactory  ser- 
vice to  its  "custom- 
ers" very  much  in  the 
same  manner  as  a 

street  car  company,  a  water  and  light  com- 
pany, or  the  grocer  or  baker  around  the 
corner.  And  at  the  head  of  each  of  the^  de- 
partments he  found  a  board,  or  an  individual,  in 
control. 

To  this  successful  butter  and  egg  merchant — 
the  new  mayor  of  a  city  of  350,000  people — the 
job  of  rightly  comprehending,  to  say  nothing  of 
intelligently  directing  this  great  municipal  cor- 
poration, looked  like  a  mighty  big  task.  True, 
he  was  very  familiar  with  the  process  of  turning 
butter  and  eggs  into  dollars  and  cents — but 
this  was  different!  However,  like  a  true 
business  man,  he  set  about  to  learn  this  new 
executive  job — city  government.  He  made 
up  his  mind  to  discover  "what  made  the 
watch  tick"  in  the  city  hall,  and  especially  to 
ascertain  the  source  of  the  "wherewithal," 
and  the  close  connection  between  the  tax- 
payers' "outs"  and  Kansas  City's  "ins." 

Then  followed  tedious  hours,  days,  and  weeks, 
while  the  Mayor,  surrounded  by  instructors, 
departmental  heads  and  the  like,  bent  over  wide 
tables  and  delved  into  great  books — amazing 
arrays  of  tabulated  reports  and  totals — striving 
to  gather  something  beyond  a  mere  super- 
ficial knowledge  of  how  and  where  the  city 


Said  Mayor  Frank  H.  Cromwell:  "A  year  as 
Mayor  of  Kansas  City  has  revealed  to  me  that 
an  astoundingly  large  number  of  our  citizens 
are  ignorant  of  the  functions  of  the  various 
city  departments.  Only  a  few  persons  find  time 
to  attend  public  meetings.  I  believe  that  radio 
offers  a  medium  through  which  citizens  of  a 
municipality  who  have  little  or  no  opportunity 
to  learn  the  details  of  municipal  government, 
can  inform  themselves  of  the  work  of  the 
various  departments." 


obtained  the  funds  which  are  the  lubricant  of 
city  government,  and,  more  important,  how  to 
direct  the  distribution  of  these  millions  of 
dollars. 

After  weeks  of  study  along  this  line, 
bringing  gradual  enlightenment,  he  came  to 
realize  that  his  own  ignorance  of  the  function- 
ing of  the  municipal  government  was  as  nothing 
compared  with  what  the  average  voter  knew 
of  the  conduct  of  his  city's  business. 

Here  was  a  real  problem — and  one  of  univer- 
sal application.  The  merchant,  to  exist,  rea- 
soned the  mayor,  must  sell  his  wares,  and  to  sell 

his  wares  he  must  ad- 
vertise. The  city,  with 
a  great  stock  of  wares 
to  sell,  also  should 
advertise.  The  voter 
— the  ultimate  con- 
sumer at  the  city  store 
— must  know  what  is 
on  the  counters  and 
shelves.  He  must  be 
informed  of  the  "ser- 
vice" offered  by  his 
city. 

The  mayor  pon- 
dered over  this  prob- 
lem. How  was  he  to  "take  the  city  govern- 
ment to  the  voter?"  How  was  the  voter  "to 
be  sold"  on  the  proposition  of  operating  his 
city  government? 

After  compressing  the  problem  into  this 
understandable  form,  Mayor  Cromwell  com- 
piled a  list  of  prospective  advertising  mediums, 
jotting  them  down  on  a  slip  of  paper. 

"Printed  publicity  is  good,"  he  said  "pro- 
viding that  a  sufficient  number  of  people  will 
read  it. 

"  Public  meetings  will  draw  only  a  negligible 
per  cent,  of  the  population.  We  might  write 
letters,  but  that  would  entail  great  expense, 
and  perhaps  only  a  few  persons  would  pay  any 
attention  to  them. " 

On  Mayor  Cromwell's  desk,  as  he  thus  pond- 
ered this  question,  lay  a  magazine.  The  cover 
design  caught  his  attention.  It  was  of  a  wo- 
man singing  before  a  microphone,  her  voice 
being  broadcasted  by  radio  to  thousands  of 
listeners-in. 

Suddenly  Mayor  Cromwell  saw  a  "great 
light."  "That's  it!"  he  shouted.  "I'll  broad- 
cast my  lessons  in  city  government  to  the 
voter.   We'll  say  it  with  ether  waves," 

Mayor  Cromwell  likes  to  make  his  dreams 


'Selling"  the  Public  on  Better  City  Government 


301 


most 
the 


up-to-date 


come  true.  Perhaps  that  is  one  reason  why 
he  made  a  success  in  the  butter  and  egg  busi- 
ness; or  why  he  managed  to  win  the  race  for 
mayor  of  Kansas  City,  while  every  newspaper 
in  town  was  plugging  for  his  opponent. 

There  followed  immediately  a  conference 
with  Emory  J.  Sweeney,  president  of  the 
Sweeney  Automotive  and  Electrical  school, 
and  owner  of  one  of  the 
broadcasting  stations  in 
United  States. 

"We  could  broadcast  civic 
radio  night  programs  from  your 
station,  "explained  Mayor  Crom- 
well to  Mr.  Sweeney,  "  and  our 
big  difficulty — that  of  finding  a 
medium  of  maximum  expression 
— would  be  solved." 

Mr.  Sweeney  was  interested  in 
the  mayor's  plan.  So  a  date  was 
set  for  the  first  civic  radio  night. 
It  was  announced  as  "  Hospital 
and  Health  Board  Night,"  with 
Dr.  E.  H.  Bullock,  Kansas  City 
health  director,  as  principal 
speaker,  and  Mayor  Cromwell  as 
master  of  ceremonies. 

Thousands  of  radio  set  owners, 
not  only  residents  of  Kansas 
City,  but  of  surrounding  com- 
munities, were  surprised  and 
pleased  by  the  new  type  of  pro- 
gram. Letters  of  commendation 
and  telephone  calls  poured  into 
the  mayor's  office,  calling  for 
"more  along  the  same  lines." 

The  feature  of  the  second 
civic  radio  night  was  an  address 
by  John  Pew,  City  Counselor. 
His  address  was  aimed  directly 
at  voters  and  taxpayers,  and 
he  explained  to  them  exactly 
"where  the  money  goes"  in  keeping  the  wheels 
of  the  city  government  revolving  at  the  neces- 
sary speed. 

The  third  city  official  whose  voice  was 
broadcasted  from  station  WHB  was  Charles 
Tucker,  President  of  the  Board  of  Public 
Welfare;  he  explained  the  operation  of  men's 
and  women's  reformatories,  the  municipal 
farm,  and  the  scores  of  similar  activities  con- 
nected with  his  department. 

Fred  E.  Turner,  President  of  the  Fire  and 
Water  Board,  was  the  next  speaker.  He 
described  the  romance — and  service — rendered 


MAYOR  FRANK  CROMWELL 

Who  is  letting  Kansas  City  listeners- 
in    know    how    their    city    is  run 


by  the  fire  department,  to  each  home  in  the 
city,  and  the  courage  and  loyalty  of  the  grizzled 
firemen,  on  a  par  with  that  of  the  soldier  upon 
the  battlefield. 

Chas.  S.  Foreman,  Assistant  Engineer  for 
the  Water  Department,  told  citizens  and 
voters  of  the  work  in  connection  with  furnish- 
ing a  constant  supply  of  fresh  water  for  the 
city,  while  Ernest  Tucker,  Secretary  of  the 
City  Plan  Commission,  outlined 
some  of  the  commission's  plans 
for  the  future  betterment  and 
growth  of  Kansas  City. 

But  the  big  sensation  and  dra- 
matic coup  of  Mayor  Cromwell's 
civic  radio  night  programs  was 
entirely  different  from  any  cf 
these,  and  one  which  almost 
took  away  the  breath  of  a  public 
accustomed  to  thrills  of  many 
kinds. 

"We'll  introduce  something 
lively  now,"  said  the  mayor  to 
his  assistants.  "  Why  not  per- 
mit the  voters  to  listen-in  on  a 
session  of  one  of  our  municipal 
courts— allow  them  to  learn  of 
the  functioning  of  this  depart- 
ment of  our  city  government?" 

Thus  it  happened,  one  night  in 
March,  radio  fans  in  Kansas  City 
and  the  Middle  West  were  startled 
by  this  announcement: 

"This  is  station  WHB,  broad- 
casting a  session  of  the  North  Side 
Court,  Michael  J.  Kilroy,  pre- 
siding judge,  as  one  of  Mayor 
Cromwell's  civic  radio  night 
programs.  Just  a  minute, 
please. " 

A  whirring  drone  followed — a 
minute  of  suspense,  then — 
"  The  next  case, "  said  the  voice  of  the  bailiff, 
"John  Strong  vs.  the  City;  charged  with 
drunkenness. " 

The  arresting  officer  was  called.  John  Strong 
could  be  heard  walking  up  to  the  bench. 

"John  Strong,  you  are  charged  with  drunk- 
enness," came  the  voice  of  Judge  Kilroy  over 
the  air.    " Guilty  or  not  guilty?" 

"Guilty,  your  honor,"  replied  the  prisoner. 
"  I'm  always  drunk — when  I  can  get  it!" 

"One  hundred  dollars!"  came  the  judge's 
reply. 

And  down  through  a  regular  docket  of  the 


302 


Radio  Broadcast 


court  was  broadcasted  a  slice  of  the  comedy 
and  tragedy  found  daily  in  the  courts  of 
Kansas  City,  yet  beyond  the  imagination  of 
many  of  the  old-time  residents  of  the  town.  It 
was  a  civic  program  with  an  appeal  which 
was  new  to  thousands  of  people  wearing  head- 
sets that  night  in  March. 

Mayor  Cromwell,  to  date,  had  played  his 
trump  card  in  educating  the  voter  along  the 
lines  of  better  city  government;  had,  in  fact, 
taken  the  mysteries  and  practical  workings  of 
the  various  departments,  and,  more  startling 
still,  the  courts  themselves,  right  into  the  homes 
of  tax-payers  and  voters,  and  had  shown  them 
the  cost  of  operation  and  the  results. 

But  what  has  been  done  is  just  a  beginning. 
The  mayor  is  convinced  that  this  innovation 
is  proving  a  valuable  medicine  in  curing  some 
of  the  city's  chronic  ills. 

"  We  plan  to  broadcast  a  program  each 
month,"  declared  Mayor  Cromwell,  "and,  to 
the  best  of  my  knowledge,  this  stunt  is  the 
first  of  its  kind  in  the  United  States.  1  believe 
it  is  educational  and  will  go  a  long  way  to- 
ward bringing  the  city  government  closer  to 


the  people  who  pay  to  maintain  it,  and  I  believe 
further,  judging  from  the  interest  andfavorable 
comment,  that  the  programs'  are  appreciated." 

Let  those  who  doubt  the  tangible  results 
achieved  read  some  of  the  letters  received 
relative  to  the  civic  radio  night  programs. 
Here  is  an  excerpt  from  a  letter  written  by  one 
of  the  city's  most  successful  insurance  men: 

I  had  the  good  fortune  to  listen  in  on  the  civic 
program  broadcast  by  the  Sweeney  radio  station 
last  night  and  feel  impelled  to  write  and  say  that  I 
appreciated  it.  It  is  of  the  greatest  importance  that 
our  citizens,  who  are  all  stockholders  in  this,  our 
great  Kansas  City  corporation,  should  be  informed 
fully  as  to  all  our  civic  affairs.  .  .  .  The  pro- 
gram you  have  outlined  will  accomplish  this  most 
satisfactorily,  in  my  opinion. 

One  could  spend  a  whole  day  reading  letters 
of  this  sort — sufficient  proof  that  American 
people  are  willing  to  devote  their  time  to  a 
study  of  municipal  government,  especially . 
when  it  is  brought  to  them  in  as  novel  and 
appealing  a  manner  as  that  conceived  and  ex- 
ecuted by  Mayor  Cromwell. 


BILLIE  ORR,  OF  YOAKUM,  TEXAS,  REACHES  OUT  MORE  THAN    IOOO  MILES  WITH  THIS  SET 

He  saved  up  for  a  few  simple  parts,  wound  his  inductance  on  a  salt-box,  salvaged  some  old  telegraph  wire  for  an  aerial, 
used  his  dad's  auto  storage  battery  as  the  "A  Batt.",  and  pulled  in  Detroit,  Denver,  and  Atlanta.      He  has  left  plenty 
of  room  for  the  stage  or  so  of  amplification  which  he  hopes  to  add 


Adventures  in  Radio 


Perhaps  no  other  branch  of  science  enjoys  the  romance  and  the  spirit  of  adventure  ever  present  in  radio. 
It  matters  not  whether  it  is  the  radio  telegraph  or  the  radio  telephone;  both  have  equal  advantages  in  this 
respect.  Of  course,  radio  telegraphy  is  the  older  of  the  two,  and  its  exploits  are  more  numerous;  up  to  now, 
it  has  covered  a  wider  field  of  endeavor,  both  on  land  and  on  sea. 

Aside  from  its  everyday  uses,  radio  figures  in  a  great  many  strange  happenings  which  few  devotees  of 
broadcasting  know  about.  Many  of  these  are  unique,  not  always  possible  or  practicable  to  duplicate;  some 
are  accidents,  others  mere  incidents,  still  others  great  adventures — adventures  never  to  be  forgotten  and 
which  stand  out  as  red-letter  days  for  the  individuals  concerned. 

By  adventures  in  radio  we  mean  that  which  deviates  radically  from  the  commonplace.  Radio  has  been 
responsible  for  many  innovations.  Some  of  them  stand  out  as  monuments  of  scientific  achievement;  others 
are  ignominious  exploits  to  which  this  high  art  has  been  subjected.  All,  nevertheless,  are  intensely  interest- 
ing, breathing  the  very  spirit  of  adventure  and  romance. 

It  will  be  the  purpose  of  this  department  to  report,  from  time  to  time,  such  radio  adventures  as  have 
actually  taken  place,  with  real  human  beings  as  principals.  The  series  will  range  over  the  entire  world, 
including  incidents  in  Sweden,  Patagonia,  and  far-off  Japan  as  well  as  in  the  United  States. 

We  shall  be  glad  to  receive  accounts  of  radio  adventures  from  readers  of  the  magazine,  either 
their  own  experiences  or  authentic  experiences  of  others. — The  Editor. 


When  Messina  was  Destroyed 


THE  following  paragraphs  are  from  a 
letter  received  by  Radio  Broadcast 
from  Mr.  Stuart  Lupton,  now  American 
Consul  at  Chefoo,  China: 

In  the  latter  part  of  1908  I  was  appointed  Vice 
Consul  at  Messina,  Italy,  arriving  at  my  post  on 
December  22nd.  At  5:20  a.m.,  December  28th,  the 
city  was  almost  totally  destroyed  by  a  disastrous 
earthquake.  Owing  to  my  having  changed  my 
lodgings  on  the  26th,  I  was  fortunate  enough  to 
escape  injury.  As  soon  as  I  could  I  made  my  way 
to  the  Consulate,  becoming  more  and  more  aware  of 
the  tremendous  damage  done  as  I  walked  along  in 
rather  a  dazed  condition.  On  my  arrival,  I  found 
the  place  a  heap  of  ruins  which  I  had  great  difficulty 
in  distinguishing.  I  realized  that  there  was  no 
chance  of  the  Consul  or  his  wife  having  escaped,  and 
also  that  matters  looked  black  for  me.  I  knew  very 
few  people  in  the  city,  was  practically  penniless  as  I 
had  not  drawn  any  money  after  my  arrival,  and  my 
knowledge  of  Italian  consisted  of  less  than  a  dozen 
words.  I  found  all  public  services  had  stopped, 
cables  were  broken,  land  lines  down  and  altogether 
things  looked  hopeless.  That  night  I  was  a  refugee 
on  board  a  merchant  vessel  in  the  harbor.  Seventy- 
eight  people  were  packed  in  a  small  saloon,  two  or 
three  cabins,  and  connecting  passageways,  with  the 
rain  coming  down  in  sheets.  The  next  morning  we 
all  had  to  go  ashore  again,  as  the  steamer  was  to  sail 
for  Constantinople.  Shortly  afterward  the  British 
cruiser  Sutlej  came  into  port,  stopped  for  about  four 
hours,  and  left  again  with  1,100  wounded  on  board. 


As  the  last  boat  was  leaving  for  the  ship,  I  had  an 
inspiration.  Seeing  a  piece  of  brown  paper  lying 
on  the  ground  I  picked  up  the  cleanest  portion  and 
scribbled  a  message  to  the  Captain  of  the  Sutlej, 
asking  if  he  would  wireless  a  message  to  our  Consul 
at  Malta,  to  be  relayed  to  the  Department  of  State. 
A  sailor  said  he  would  give  it  to  the  Captain,  but 
did  not  know  whether  it  could  be  sent  or  not. 
On  the  following  Saturday,  I  found  that  the  mes- 
sage had  been  sent,  and  that  it  was  the  first  au- 
thentic news  of  the  disaster  received  in  the  United 
States. 

About  this  time  I  went  on  board  the  British  Crui- 
ser Muierva  to  call  on  the  Captain,  and  while  on 
board  was  told  the  following  story.  Captain  Cagni, 
one  of  the  best  known  and  bravest  officers  of  the 
Italian  Navy  at  the  time,  had  arrived  in  Messina 
in  command  of  the  battleship  Napoli.  On  arrival, 
he  paid  several  visits  of  ceremony,  one  of  them  be- 
ing to  Captain  Wake,  of  the  Muierva.  He  told  Cap- 
tain Wake  that  he  had  started  from  Naples  to 
Gibraltar  a  day  or  two  before  the  earthquake,  and 
when  nearing  the  latter  port  his  wireless  operator 
had  intercepted  a  fragment  of  a  message.  All  that 
was  received  was,  "Messina  destroyed."  At  that 
time  there  was  a  great  deal  of  friction  between  Italy 
and  Austria,  so  Cagni  jumped  to  the  conclusion  that 
war  had  been  declared  and  that  an  Austrian  squadron 
had  bombarded  the  city.  Hence  he  turned  and 
went  full  steam  for  Messina  with  the  full  intention 
of  engaging  any  Austrian  man  of  war  he  might  meet. 
Fortunately,  none  was  encountered,  or  the  World 
War  would  have  started  ahead  of  time. 


THE   PRIZE-WINNING  CONTRIBUTIONS  ARE  IN  THIS  LITTLE  PILE 
Photo  taken  after  the  five-day  blizzard  which  effectively  tied  up  traffic  on  the  Editor's  desk 

Porto  Rico  Fan  Wins  "How  Far?" 

Contest 

Richard  Bartholomew  of  Garrochales,  P.  R.,  Captures  First  Prize — a  De  Forest 
D-7  Reflex  Loop  Receiver — with  Home-Made  Three-Circuit  Regenerative  Re- 
ceiver of  Unique  Design.    Hears  Many  West  Coast  Stations  Regularly.    His  Story 

Before  Mr.  Bartholomew  tells  you  about  his  very  remarkable  reception  and  his  more  remarkable  re- 
ceiver, there  are  a  few  words  we  want  to  say  about  our  "How  Far?"  Contest. 

As  you  may  remember,  our  first  contest — "  How  Far  Have  You  Heard  on  a  Single  Tube?" — was  a  great 
success,  so  great,  in  fact,  that  we  felt  sure  that  one  allowing  any  number  of  tubes  and  any  kind  of  a  receiver 
would  be  of  even  more  interest  to  you.  Accordingly,  we  announced  the  second  contest,  figuring  that  it 
would  be  successful  from  the  firing  of  the  first  gun. 

After  three  months  of  waiting  for  a  publishable  article  for  this  contest,  we  decided  that  one  of  two 
things  had  occurred:  either  the  interest  in  DX  work  had  taken  a  sudden  and  universal  slump  or  you  were 
all  sitting  tight,  figuring  on  coming  up  strong  on  the  last  lap  and  crossing  the  finish  line  a  winner.  If  you 
could  see  our  desk  for  an  instant  you  would  appreciate  that  the  first  of  our  suspicions  was  groundless. 

We  are  snowed  under.  To  be  frank  about  it,  we  were  entirely  unprepared  to  handle  the  reams  of  material 
that  arrived  in  time  to  be  included  in  the  contest.  For  the  next  week  or  so  we  are  going  to  be  up  to  our 
ears  and  no  mistake,  but  it  is  going  to  be  great  fun,  and  we  are  sure  that  many  of  the  articles  will  be  suitable 
for  publication. 

And  the  articles  themselves  are  not  all  that  we  have;  one  of  the  fellows  went  as  far  as  making  dictaphone 
records  of  the  stations  he  heard.  Unfortunately  these  records  failed  to  stand  the  trip  and  arrived  in  a  more 
or  less  pulverized  condition.  But  with  photos  and  diagrams  and  broadcasting  maps  and  lists  of  stations 
and  distances  heard  and  descriptions  of  receivers  and  two  or  three  sample  home-made  coils  (all  "world- 
beaters"),  as  well  as  a  tremendous  amount  of  "dope"  on  many  "best"  circuits — we  have  something  to  do. 

As  you  may  remember,  in  the  rules  for  our  contest  the  following  paragraph  appeared: 

"  In  judging  contributions,  the  quality  and  interest  of  photographs,  text,  and  drawings,  and  the  origin- 
ality and  general  effectiveness  of  the  apparatus  described  will  have  greater  weight  than  the  list  of  stations 
heard,  although  a  long  list  of  distant  stations  will  distinctly  help." 

The  contestant  whose  material  measured  up  best  has  been  chosen;  but  the  short  time  remaining  before 
we  go  to  press,  and  the  fact  there  are  several  contestants  well  toward  the  lead  whose  work  is  so  nearly 
equal  that  a  hasty  decision  might  be  an  unjust  one,  make  it  impossible  for  us  to  announce  the  remaining 
three  prize  winners.  They  will  therefore  be  announced  in  the  next  issue  and  several  other  articles  deserving 
honorable  mention  will  also  be  published  if  space  permits. — The  Editor. 


A  Neighbor  at  Three  Thousand  Miles 

By  RICHARD  BARTHOLOMEW 

(FIRST  PRIZE) 


NATURALLY  it  has  been  of  much 
interest  to  me  to  sit  here  in  Porto 
Rico  and  listen  to  all  parts  of  the 
United  States,*  and  up  into  Can- 
ada, and  over  to  Cuba;  but  what 
appealed  to  me  still  more  was  to  sit  here  in  my 
shirt  sleeves,  with  all  doors  and  windows  open, 
and  listen  to  reports  of  five,  six,  or  seven  inches 
of  snow  and  the-  thermom- 
eter ranging  from  freezing 
down  to  fifteen  below  zero. 
Then  was  when  I  could  sit 
back  and  (if  mean  enough) 
give  you  the  laugh;  but  if  I 
listened  in  long  enough  I 
would  again  get  back  to  a 
warm  climate — California — 
although  there  the  time 
was  four  hours  later  than 
in  Garrochales. 

My  set  is  of  the  regenera- 
tive type,  but  due  to  the 
hook-up  I  use  and  a  special 
method  of  shielding,  there 
is  absolutely  no  body  capacity 
noticed,  even  while  work- 
ing on  stations  3,525  miles 
away.  In  one  instance,  I 
adjusted  the  receiver  to  bring  in  KFI,  Los 

*Mr.  Bartholomew  sent  with  his  manuscript  and  photos 
a  whole  sheaf  of  letters  which  he  had  received  from  far- 
away broadcasting  stations,  verifying  his  records  and 
commenting  on  his  remarkable  work.  Here  are  excerpts 
from  three  of  these  letters: 

"  I  wonder  if  you  have  received  a  notification  that  you 
are  the  winner  of  the  W  estern  Electric  ear  phones  awarded 
to  the  person  who  heard  the  concert  on  October  28th,  the 
farthest  distance  from  Minneapolis?  The  announcement 
created  a  tremendous  amount  of  interest  in  this  city.  On 
that  evening  we  were  heard  by  forty-six  states  in  the  Union, 
four  provinces  in  Canada,  in  addition  to  you. 

Program  Director,  WLAG." 

"We  received  your  card  reporting  hearing  our  Radio- 
phone and  wish  to  thank  you  very  much  for  same.  We 
believe  this  reception  to  be  a  record  for  a  50-watt  trans- 
mitter. WKY  Radio  Shop, 

Oklahoma  City,  Okla." 

"You  are  our  neighbor  .  .  .  you  are  certainly  doing 
some  good  reception.  Hale  Bros.,  Inc., 

Radiophone  Broadcasting  Station  KPO, 
San  Francisco." 
This  last  station  is  3,500  miles  from  Porto  Rico! 


Angeles,  and  without  changing  the  dials  1  heard 
about  20  different  selections.  This  was  on  their 
opening  night.  1  have  heard  them  many  times 
since. 

The  adjusting  of  this  set  is  more  than  simpie, 
for  often  I  have  tuned  in  eight  stations  only  by 
turning  the  grid  dial.  At  one  time  1  had  to 
be  away  from  home  a  while,  and  so  showed  my 


wife  how  to  connect  the  batteries,  as  she  wanted 
to  try  the  set.  Upon  returning,  1  found  that 
she  had  had  music  every  night,  and  the  first 
night  received  eighteen  selections,  with  names  of 
pieces  and  artists,  from  WGY,  i  ,6oo  miles  away. 

Now  we  might  as  well  roll  up  our  sleeves  and 
get  right  to  the  principal  business  of  the  day, 
which  is,  how  you  can  make  a  receiver  such  as 
mine  and  how  you  can  use  it  to  best  advantage. 

MATERIALS  NEEDED  FOR  CONSTRUCTION 

1 5  binding  posts 
18  switch  points 

3  switch  levers 

2  two-circuit  jacks 

1  single-circuit  jack 
!  Bradleystat 

2  wire-bound  rheostats  (or  Bradleystats) 
i  potentiometer 

i  grid  leak  (i  megohm) 

i  grid  condenser  (.00025  mfd.) 

(1  double  mounting  if  Radio  Corp.  materials  are  use  !) 

3  tube  sockets 


THE  DETECTING  AND  AMPLIFYING  UNIT  SHOWING  SHIELDED  TUBES 


306 


Radio  Broadcast 


2  transformers  audio.  (Amertran  or  UV-712) 

1  .001  mica  phone  condenser 

1  panel,  7"  x  18"  for  receiver  (bakelite) 

1  panel,  7"  x  12"  for  detector  and  amplifier  (bakelite) 

1  piece  of  bakelite,  rubber  or  wood,  7  x  1 1,  for  mounting 

transformers  and  sockets  in  detector  unit 

2  vernier  controls  for  variometers,  friction  type 

12  pieces  of  buss  wire  or  No.  18  wire  with  spaghetti 

2  variometers  having  66  turns  on  the  rotor  and  60  on  the 

stator.    Those  wound  with  large  wire  and  not  using 

shafts  for  contacts  are  preferred 
1  variocoupler,  same  type  as  variometers,  but  with  30 

turns  on  the  rotor  and  about  48  on  the  stator,  tapped 

so  that  it  can  be  adjusted  to  every,  or  every  other,  turn 
1  piece  of  tubing  of  non-conductive  material,  dia.  4", 

length  1 1" 
i  lb.  of  No.  20  D.  C.  C.  wire 

3  dials.    One  for  each  variometer  and  one  for  coupler 
1  4-volt  flashlight  battery 

1  piece  of  copper  foil.    7"  x  18"  (shield) 
A  few  odd  screws,  brads  and  stove  bolts 
Enough  \"  lumber  to  make  the  two  cabinets,  one  7"  x  8" 

x  18"  and  the  other  7"  x  8"  x  12".    Stain  for  same 
Small  bottle  of  shellac  for  painting  loading  coil 

4  brass  hinges  (small)  with  screws 

Regular  equipment: 

1  6-volt  A  Battery  (storage) 

2  22I  or  24  volt  B  battery  either  dry  or  storage 
1  pair  of  good  phones 

1  detector  tube,  UV-200 

2  amplifying  tubes,  UV-201  or  UV-201-A 
Antenna  and  ground  equipment. 


o 


CONSTRUCTION  OF  THE  RECEIVER 

N  the  piece  of  tubing  listed  just  above, 
make  two  small  holes  \  in.  from  the  edge 
and  j  in.  apart.  Through  these  two  holes 
fasten  the  end  of  the  No.  20  wire  and  make 
thirty  turns,  using  the  system  of  bank  winding 
illustrated  in  Fig.  1 .  Make  the  first  turn  |  in. 
from  the  edge  and  wind  the  wire  in  the  same 
direction  as  the  windings  of  the  stator  of  the 
plate  variometer.    At  thirty  turns  take  off  a 


REAR  VIEW  OF  THE  RECEIVING  UN 


FIG.  I 

Showing  how  the  turns  are  made  in  bank-winding 

tap,  then  wind  thirty  more  and  fasten  the  end 
as  before.  This  makes  a  coil  of  60  turns  with 
a  tap  at  30.  Now  fasten  this  coil  on  the  left 
hand  side  of  the  plate  variometer,  as  shown  in 
Fig.  2.  (The  coil  is  shown  at  the  right  of  the 
variometer  in  Fig.  2,  but  this  is  because  the 
view  is  from  the  rear).  The  writer  did  this 
with  shellac,  but  any  method  will  do.  Place 
the  taps  so  that  they  will  be  toward  the  panel. 

Paste  over  the  face  of  the  panel  a  piece  of 
white  paper  and  on  this  draw  out  to  size  the 
dials,  binding  posts,  switches,  switch  points, 
and  verniers,  always  leaving  enough  space  for 
the  sides  of  the  cabinet.  Put  on  this  drawing 
all  holes  to  be  made,  to  size,  their  centres,  and 
whether  to  be  counter-sunk  or  not. 

Now  try  placing  all  the  parts  on  the  panel 
as  indicated  by  the  drawing  you  have  made, 
including  variometers  and  coupler,  and  see 
that  they  do  not  interfere  one  with  the  other. 
(The  writer  found  that  he  could  best  place  the 
variometers  13  inches  apart,  centre  to. centre, 
with  the  shaft  3!  inches  from  the  top  of  the 
panel.  The  coupler  shaft  went  half  way  be- 
tween those  of  the  variometers  and  1  inch 
above  them.)  But  as  all  variometers,  etc., 
are  different,  you  will  have  to  experiment  a 
bit  to  determine  how  to  place  and  fasten  them 
on  the  panel. 

Using  a  centre  punch, 
punch  each  hole  and  bore 
it.  Glue  the  copper  foil  to 
the  back  of  the  panel  and 
cut  away  around  the  holes 
for  the  shafts,  all  switches, 
switch  points,  and  all  bind- 
ing posts  except  the  ground 
and  filament  posts.  Be  sure 
that  the  foil  is  not  closer 
than  iV  inch  to  any  of  the 
parts  other  than  the  two 
binding  posts  mentioned. 
Solder  the  shield  to  these 
two  posts. 

Now  you  are  ready  to 
mount  all  the  parts.  Do  so 
and  wire  them  according  to 


A  Neighbor  at  Three  Thousand  Miles 


307 


TAPS. 


the  diagrams  (Figs.  3,  4,  and 
5).  Solder  all  contacts  and 
run  wires  in  straight  lines 
makingturns  at  right  angles. 
Neat,  painstaking  work  at 
this  point  will  amply  repay 
you  for  the  longer  time  it 
takes. 

CONSTRUCTION   OF  THE  DE- 
TECTOR AND  AMPLIFIER 

THE  panel  of  the  ampli- 
fier unit  is  laid  out  and 
handled  in  the  same  way  as 
that  of  the  receiver,  except 
that  there  is  no  need  of  a 
shield.  Keep  in  mind  that 
the  binding  posts  have  to 
correspond  with  those  in  the 
receiver,  so  should  be  placed 
at  the  same  distances  from 
the  top  of  the  panel. 

The  base  supporting  the 
sockets,  transformers,  etc. 
rests  upon  the  jacks  and  is 
bolted  to  them.  This  means 
that  one  small  hole  has 

to  be  made  in  the  detector  and  second-stage  made  for  each  light  are  placed  directly  above 
jacks,  through  which  the  base  is  made  fast  the  jacks;  the  top  hole  is  1  inch  from  the  top 
with  two  small  bolts.  of  the  panel. 

The  Bradleystat  is  placed  on  the  left  hand  The  parts  are  now  mounted  on  the  panel  and 
side  of  the  panel.  Then  comes  the  two  wire-  the  base  (of  bakelite  or  wood)  is  put  in  place 
wound  rheostats  and  last  the  potentiometer,  after  cutting  out  a  section  to  allow  for  the  po- 
These  are  evenly  spaced  across  the  panel  and  tentiometer  and  B  battery  leads.  Now  set 
are  on  the  middle  or  central  line.  The  jacks  the  sockets,  G  battery,  transformers,  and  grid 
are  placed  halfway  between  these  about  ijin.  (leak  and  condenser)  mounting  in  the  best 
from  the  bottom  of  the  panel.    The  five  holes    possible  positions.    Try  to  keep  the  grid  leads 


fig.  2 

Plat;  variometer  and  coil,  rear  view 


f 

GRID 


®- 

FIL- 


PLATE 


PLATE 
®— 


PLATE  VAR. 


11  jf^ 


COIL 


ANT. 
— © 


GRID  VAR. 


® 


© 


GROUND 


fig.  3 

Schematic  wiring  diagram  of  the  receiver  unit,  rear  view 


308 


Radio  Broadcast 


as  short  as  possible,  the  cores  of  the  trans- 
formers at  right  angles  to  one  another,  and  the 
lights  directly  back  of  the  holes  in  the  panels. 
When  well  placed,  mark  the  position  of  each 
piece  on  the  base,  also  mark  holes  for  running 
the  wires  to  the  primaries  of  the  transformers, 
plates  of  the  tubes,  and  condenser  shunted 
across  from  the  plate  to  the  filament  (phone 
condenser,  .001).  Remove  the  base,  bore  all 
holes,  mount  the  parts,  and  replace  for  wiring. 

Don't  overlook  the  negative  binding  post 
for  the  B  battery,  as  this  is  placed  on  the  back 
side  of  this  base.  A  hole  is  made  through  the 
rear  of  the  cabinet  to  admit  the  lead. 

WIRING  THE  RECEIVER 

MAKE  all  leads  as  short  as  you  can,  running 
them  horizontally  or  vertically,  with  the 
turns  forming  sharp  right  angles. 

Solder  all  connections  possible,  and  be  sure 
that  all  unions  are  good  and  clean. 

The  diagram,  Fig.  3,  is  that  of  the  rear 
view  of  the  receiver.  Note  posts  "Fil-"and 
"Ground" ;  they  are  the  ones  that  should  be  sol- 
dered to  the  shield.  The  ground  wire  goes 
to  the  fine  taps  at  switch  marked  A,  and  the 
switch  and  end  of  coil  are  connected  as  in  the 
circuit  diagram  (Fig.  5).    The  aerial  goes  to 


the  coarse  taps  or  switch  B  (Fig.  3).  Switch 
C  is  use  for  the  loading  coil. 

The  taps  at  A  are  taken  every  turn. 

The  taps  at  B  are  taken  every  six  turns. 


WIRING  THE  DETECTOR  AND  AMPLIFIER 


M 


AKE  all  the*  leads  as  short  as  possible, 
-especially  the  grid  leads;  also  be  careful 
that  the  grid  and  plate  leads  do  not  run  parallel 
for  any  great  distance. 

The  binding  post  for  the  negative  of  the  B 
battery  is  placed  on  the  base  supporting  the 
sockets,  etc.,  and  a  hole  is  made  in  the  cabinet 
back  to  admit  the  lead. 

All  tubes  are  wound  with  No.  20  wire.  This 
can  be  done  in  any  way  as  long  as  the  wire 
makes  a  perfect  shield  as  high  up  on  the  tube 
as  possible,  leaving  the  end  of  the  tube  uncov- 
ered (see  photo  showing  tubes  wound  with 
wire) 
with 

wire  are  fastened  together  and  grounded  to  the 
negative  of  the  filament,  or  negative  of  the 
A  battery. 

Solder  all  connections,  and  when  everything 
is  ready  try  lighting  the  tubes  before  you 
connect  up  the  B'battery.  It  may  save  blow- 
ing out  a  tube. 


The  writer  fastened  the  wire  in  place 
small  pieces  of  tape.    Both  ends  of  the 

J 

or 


I 

-F 

+  6 

SEC. 

PRI. 

G 

P 

®— 

GRID 


FIL. 
-® 


{  MEG. 

JTL 


.00025 


-<•> 

PLATE 

PLATE 
-® 


TRANS  F. 


FIG.  4 

Schematic  wiring  diagram  of  detector  and  amplifier  unit,  rear  view 


A  Neighbor  at  Three  Thousand  Miles 


309 


FIG.   5.     CIRCUIT  DIAGRAM  FOR  MR.   BARTHOLOMEWS  COMPLETE  RECEIVER 

1 — Antenna;  2 — Ground;  y — Switch  for  fine  taps^on  coupler;  4 — Switch  for  coarse  (six  turns)  taps  on  coupler;  5 — Vario- 
coupler;  6 — Grid  variometer;  7 — Switch  for  loading  coil;  8 — 60-turn  coil  on  4"  tube;  9 — Grid  condenser,  .00025;  10 — Grid 
leak,  1  megohm;  11 — Plate  variometer;  12 — Two-circuit  jack;  13 — UV-200  tube;  14 — Bradleystat;  15 — Bradleystats  or 
other  rheostats;  16 — UV-201  or  UV-201-A;  17 — Audio  transformers;  18 — Potentiometer,  200  ohms;  19 — Single-circuit 
jack;  20 — Phone  condenser,  .001;  21 — This  line  represents,  the  copper  shielding;  22 — No.  20  wire  is  wound  around  the 
tubes  as  shields,  connected  to  the  negative  of  the  A  battery  or  filament  (connection  not  shown  here);  A — 6-volt  storage 
battery;  B — Two  24-volt  storage  batteries  for  plate  circuit  (dry-cell  B  batteries  will  do);  C — 4-volt  flashlight  battery 


GETTING  THE  MACHINE  READY  TO  USE 

BE  VERY  careful  that  all  leads  to  and  from 
each  piece  of  apparatus  are  correct. 
Put  the  machine  in  a  place  or  on  a  table 
wide  enough  so  that  you  can  rest  your  arms 
while  making  adjustments.  This  is  necessary 
in  picking  up  DX  stations  as  the  slighest  turn 
may  make  the  difference  between  failure  and 
success. 

Place  the  batteries  as  close  to  the  machine  as 
possible  (see  to  it  that  they  are  well  charged 
and  kept  so,  for  although  you  may  be  able  to 
pick  up  a  close  station  on  weak  batteries,  you 
will  never  hear  a  distant  one). 

Keep  a  piece  of  emery  paper  near  the  ma- 
chine if  you  are  using  sockets  whose  contacts 
are  of  the  spring  type  that  only  touch  the  tip 
of  the  tube.  It  will  be  necessary  to  clean  these 
tips  every  few  days. 

TUNING 

SET  the  grid  and  plate  variometer  dials  so 
that  the  rotors  are  at  right  angles  to  the 
windings  of  the  stators. 

Set  the  coupler  dial  so  that  the  windings  of 
stator  and  rotor  are  nearly  parallel.  Leave  it 
in  this  position  until  the  last  when  a  slight 
change  may  increase  the  signals. 

Set  the  coupler  taps  switch  so  that  there 
will  be  about  24  turns  used.    This  applies  to 


a  single-wire  aerial  about  160  feet  long  from 
the  receiver  to  the  furthermost  point.  For 
shorter  aerials  you  will  need  more  turns. 

Set  the  loading  coil  switch  so  that  the  loading 
coil  is  cut  out  of  the  circuit.  Do  not  bother 
with  this  coil  until  you  have  learned  to  operate 
the  machine  without  it. 

Place  the  phone  plug  in  the  first-stage  jack 
and  turn  on  the  amplifying  tube,  slightly  for  a 
UV-201-A  and  almost  full  for  a  UV-201.  Now 
light  the  detector  tube  which  is  controlled  with 
the  Bradleystat.  This  should  be  turned  on 
until  you  hear  a  hissing  in  the  phones.  Then 
turn  it  back  a  slight  fraction  of  a  turn. 

The  potentiometer  is  turned  to  approx- 
imately the  middle  point  if  using  about  18  volts 
on  the  plate  of  the  detector. 

Now  rotate  the  grid  variometer  toward  the 
left,  slowly,  and  listen  for  the  whistling  that 
indicates  a  broadcasting  station.  If  you  have 
to  move  it  a  great  distance  then  a  slight  ad- 
justment of  the  plate  variometer  may  be  neces- 
sary to  keep  the  tube  near  the  hiss. 

When  a  signal  is  heard,  readjust  the  fila- 
ments of  the  amplifier  and  detector  tubes  until 
the  signal  is  strongest,  using  the  least  current 
necessary.  Now  readjust  the  variometers 
using  the  verniers  and  always  keeping  the 
station  within  hearing.  Usually  this  will 
mean  turning  first  one  and  then  the  other 
dial  toward  the  left.    At  some  point  you  will 


3io 


Radio  Broadcast 


find  that  the  station  will  drop  in  clearly  or 
drop  out.  If  it  comes  in  clearly,  O.K.,  but  if 
it  drops  out,  you  have  turned  too  far,  either 
with  one  or  both  variometers.  Take  it  slowly 
at  first.  If  you  get  the  station,  but  the  signals 
are  not  clear,  try  adjusting  the  Bradleystat 
and  potentiometer.  These  last  two  adjust- 
ments are  very  necessary  on  distant  stations. 

It  might  be  well  to  add  here  that  if  any 
capacity  effect  is  noticed  on  either  variometer, 
try  reversing  the  two  leads  and  see  if  that  does 
not  do  away  with  it. 

If,  after  trying  all  this,  you  do  not  pick  up 
any  signals,  change  your  switch  on  the  coupler 
primary  and  try  again.  The  longer  the  aerial, 
the  fewer  turns  you  need  on  the  primary.  The 
shorter  the  aerial  and  longer  the  wavelength 
of  the  station,  the  more  turns  you  need. 
Now,  if  you  don't  hear  anything,  check  over  the 
wiring  again. 

The  loading  coil  in  the  secondary  can  be 
used  for  all  broadcasting  stations,  but  it  is 
most  helpful  on  the  class  B  stations  or  those 
having  a  wavelength  of  400  meters  and  over. 
In  this  case  use  the  middle  tap  (30  turns)  and 
for  500  to  600  meters  use  the  full  coil  (or  60 
turns).  It  will  be  found  with  this  coil  in  the 
circuit  that  more  attention  has  to  be  paid  to 
the  adjustment  of  the  plate  variometer,  and  the 
writer  believes  that  it  makes  his  machine  much 
more  selective.  For,  while  using  this  coil,  he 
can  separate  stations  that  could  not  be  separ- 
ated without  it.  It  will  also  be  found  that 
where  a  station  comes  in  clearly  with  the  grid 
variometer  the  set  at  1 10  (on  a  1800  dial),  and 
the  plate  variometer  at  900  (without  the  coil), 
you  will  now  have  to  turn  the  grid  variometer 
to  about  ioo°  and  the  plate  variometer  will 
have  to  be  set  around  1  io°.  But  with  practice 
this  coil  will  prove  very  efficient.  The  writer 
has  heard  three  stations  in  California  six  nights 
in  succession,  a  distance  of  more  than  3,350 
miles,  and  they  always  came  in  at  the  same 
setting  of  the  dials. 


Mr.  Bartholomew's  station  list  is  so  remark- 
able, especially  when  it  is  appreciated  that  he 
is  located  about  500  miles  south  and  900  miles 
east  of  the  lower  end  of  Florida,  that  we  are 
printing  it  in  full.*  You  will  note  that  all  the 
stations  heard  are  more  than  1,000  miles  from 
Garrochales,  and  that  six  are  more  than  3,300 
miles  away. 


CALL   LETTERS                       LOCATION  MILEAGE 

KDKA  East  Pittsburg,  Penn.  1,650 

KFI  Los  Angeles,  Calif.  3.350 

KHJ  Los  Angeles,  Calif.  3,350 

KOB  State  College,  N.  Mex  2,675 

KOP  Detroit,  Mich.  1,850 

KPO  San  Francisco,  Calif.  3.525 

KSD  St.  Louis,  Mo.  1,950 

KUO  San  Francisco,  Calif.  3,525 
Examiner 

and  Herald  Los  Angeles,  Calif.  3,350 

KYW  Chicago,  111.  2,000 

WAAK  Milwaukee,  Wis.  2,050 

WAAM  Newark,  N.  J.  1,550 

WAAP  Wichita,  Kan.  2,250 

WAAW  Omaha,  Neb.  2,300 

WBAK  Harrisburg,  Penn.  1,575 

WBAP  Fort  Worth,  Texas  2,150 

WBAV  Columbus,  Ohio  1,725 

WBL  Anthony,  Kansas  2,275 

WBT  Charlotte,  N.  C.  1,400 

WBZ  Springfield,  Mass.  1,600 

WCAL  Northfield,  Minn.  2,300 

WCX  Detroit,  Mich.  1,850 

WDAE  Tampa,  Fla.  1,225 

WDAF  Kansas  City,  Mo.  2,150 

WDAJ  College  Park,  Ga.  1,400 

WDAL  Jacksonville,  Fla.  1,250 

WDAR  Philadelphia,  Penn.  1,500 

WEAF  New  York,  N.  Y.  1,500 

WEAO  Columbus,  Ohio  1,725 

WEAY  Houston,  Tex.  2,000 

W'FAA  Dallas,  Tex.  2,100 

WFAT  Sioux  Falls,  S.  D.  2,400 

WQAM  Miami,  Fla.  1,050 

WFI  Philadelphia,  Penn.  1,500 

WGI  Medford  Hills,  Mass.  1,600 

WGM  Atlanta,  Ga.  1,500 

WGR  Buffalo,  N.  Y.  1,775 

WGY  Schenectady,  N.  Y.  1,675 

WHA  Madison,  Wis.  2,100 

WHAF  Pittsburg,  Penn.  1,650 

WHAM  Rochester,  N.  Y.  1,775 

WHAO  Savannah,  Ga.  1,250 

WHAS  Louisville,  Ky.  1,725 

WHAZ  Troy,  N.  Y.  1,675 

WHB  Kansas  City,  Mo.  2,150 

WIP  Philadelphia,  Penn.  1,500 

WJAN  Peoria,  111.  2,000 

WJAX  Cleveland,  Ohio  1,750 

WKY  Oklahoma  City,  Okla.  2,200 

WJZ  Newark,  N.  J.  1,550 

WLK  Indianapolis,  Ind.  1,825 

WLW  Cincinnati,  Ohio  1,725 

WLAG  Minneapolis,  Minn.  2,325 

WLAL  Tulsa,  Okla.  2,125 

WLAK  Bellow  Falls,  Vt.  1,700 

WLAT  Burlington,  Iowa  2,100 

WMAB  Oklahoma  City,  Okla.  2,200 

WDAP  Chicago,  III.  2,000 

WMAQ  Chicago,  111.  2,000 

WNAC  Boston,  Mass.  1,600 

WMAF  Round  Hills,  Mass.  1,600 

WMAJ  Kansas  City,  Mo.  2,150 


*Regarding  this  list,  Mr.  Bartholomew  writes: 
"  Have  also  picked  up  many  other  stations  including 
Denver,  Colo.,  and  parts  of  telephone  conversations  be- 
tween Avalon,  Calif,  and  Catalina  Island;  but  have  not 
included  them  in  this  list  as  I  have  not  heard  call  letters 
and  location  together. 

"All  of  the  above  stations  were  heard  on  one  step  of  ampli- 
fication only.  On  two  steps  I  use  a  home-made  loud  speaker 
(Baldwin  unit  and  horn),  and  with  it  I  have  heard  Califor- 
nia 30  feet  from  the  horn." 


Unloading  the  Mail  from  the  Transatlantic  Liners 


3'  1 


r  a  1  1    I  CTTF  R  C, 

,*\  L.  L-    LCI   1  Llv  J 

LOCATION 

MILEAGE 

WJvlAK 

Lockport,  in.  Y . 

1.775 

•\\r  \ /t  A  T 

vvMAl 

Deluth,  Minn. 

2.350 

WMAi 

Macon,  Ga. 

1 ,400 

WMC 

Memphis,  Tenn. 

I  ,O0O 

WOAI 

ban  Antonio,  1  exas 

2,175 

A\  r/~v  AM 

Lawrenceburg,  Tenn. 

1  ,700 

WOAW 

Omaha,  Neb. 

2,300 

woe 

Davenport,  Iowa 

2,  IOO 

WO  I 

Ames,  Iowa 

2,22  5 

woo 

Philadelphia,  1  enn. 

1 ,  5OO 

WOR 

Newark,  N.J. 

1.550 

wos 

Jefferson  City,  Mo. 

2,050 

VV  'p  A 
vv  1  r\ 

Pnrth  V\  nrth  Tpya? 

1  Ul  111     VV  UI  HI,      1  CAaJ 

2,  I  50 

WPAC 

Okmulgee,  Okla. 

2,  IOO 

WPAL 

Columbus,  Ohio 

1.725 

WOAO 

Parksburg,  Penn. 

1,525 

WRP 

Camden,  N.  J. 

I.550 

WSB 

Atlanta,  Ga. 

1,500 

WSY 

Birmingham,  Ala. 

I,600 

MR.  BARTHOLOMEW' 


CALL  LETTERS                        LOCATION  MILEAGE 

WW  I                   Dearborn,  Mich.  1,850 

WWJ                  Detroit,  Mich.  1,850 

CANADA 

CHYC                Montreal,  Quebec,  Can.  1,850 

CFAC                Calgary,  Alberta,  Can.  3,500 

CUBA 

PWX                   Habana,  Cuba  1,000 

F.  H.  Jones          Tuinucu,  Cuba  900 

AMATEURS  AND   EXPERIMENTAL  STATIONS 

2EL  (on  phone)     Freeport,  N.  Y.  1,500 

iXAE  (on  phone)  Springfield,  Mass.  1,600 

2XI  (on  phone)     Schenectady,  N.  Y.  1.675 

Total  Mileage,  Air  Line    ......  172,075 

Broadcast  Stations  Heard   90 

Average  Mileage   1,911 


S  OUTFIT  COMPLETE 


Unloading  the  Mail  from  the  Trans- 
atlantic Liners 


By  M.  G.  CARTER 


IN  ACCORDANCE  with  certain  existing 
laws,  the  contracts  with  the  various  steam- 
ship companies  provide  that  all  foreign 
mail  brought  in  on  their  ships  shall  be  de- 
livered to  the  receiving  Post  Office  at  the 
expense  of  the  steamship  companies.  The 
New  York  Harbor  Mailboat  Service  is  main- 
tained to  facilitate  the  rapid  handling  of  in- 
coming foreign  mail  by  utilizing  the  time  spent 
by  the  ships  in  passing  public  health  inspection 
at  quarantine. 

There  are  times  when  the  mail-carrying  ships 
from  South  America,  the  West  Indies  and 
abroad  arrive  too  late  to  pass  the  doctor 
at  quarantine  which  sometimes  means  a  delay 
of  twelve  hours.  However  the  mail  is  not 
delayed,  but  is  taken  aboard  the  mailboats 
and  brought  to  Pier  72,  North  River,  New 
York,  and  whence  by  trucks  or  train  to  the  dis- 
tributing Post  Offices.  This  relieves  the  steam- 
ship companies  of  the  considerable  expense  of 
trucking  the  mail  to  the  Post  Office,  and  min- 


imizes congestion  on  the  piers  after  the  ships 
have  docked. 

The  Harbor  Mailboat  S.S.  President  (radio 
call  letters,  NURL)  is  the  flagship  of  a  fleet 
which  includes  two  and  sometimes  three  steam 
lighters  each  capable  of  carrying  from  two  to 
three  thousand  bags  of  mail,  while  the  President 
has  a  capacity  of  approximately  five  thousand 
sacks. 

A  twenty-four  hour  watch  is  maintained 
every  day  of  the  year  in  all  kinds  of  weather, 
by  three  crews  both  on  the  dock  and  on  the 
mailboat.  This  is  necessary  because  the  ships 
arrive  at  all  times  of  the  day  and  night.  It  is 
the  radio  operator's  job  to  receive  notification 
of  the  approach  of  mail-carrying  vessels  as  far 
in  advance  of  their  arrival  in  quarantine  as  is 
possible;  to  ascertain  the  amount  of  mail  on 
board,  where  it  is  stored,  whether  separated 
or  not,  and  the  approximate  time  of  the  vessel's 
arrival  in  quacantine,  so  that  those  in  charge  can 
prepare  various  organizations  to  handle  the  mail. 


312 


Radio  Broadcast 


FROM  SAILOR  TO      PRESIDENT   — IN   FIVE  SECONDS 
The  Harbor  Mailboat  President  is  shown  in  action  alongside  the  Mauretania.    Fifty  sailors  on  each  side  of  the  liner  drop 
the  mail  down  the  chutes  as  fast  as  possible.    The  day  this  picture  was  taken,  7,500  bags — approximately  60  carloads  of 
mail — were  transferred  to  the  mail  boats  in  an  hour  and  twenty-eight  minutes 


By  the  receipt  of  such  information  the  extra 
men  are  not  ordered  on  duty  until  necessary. 
This  saves  the  Post  Office  Department  money 
on  each  ship  met,  amounting  to  a  considerable 
sum  at  the  end  of  the  year.  Some  of  the  ships 
carry  from  four  thousand  to  twelve  thousand 
bags  of  mail,  and  for  these,  special  schedules  are 
made  for  boats,  trains  and  auto  trucks,  and 
extra  men  must  be  secured  to  perform  the 
service  expeditiously. 

It  is  interesting  to  note  that  during  the  past 
year  1470  ships  were  met  and  approximately 
750,000  bags  of  foreign  mail  handled.  Decem- 
ber was  the  heaviest  month,  with  a  record  of 
95,801  bags  taken  from  the  ships  at  quaran- 
tine. 

The  Post  Office  Department  publishes  a  list 
of  mail-carrying  ships  and  their  expected  time 
of  arrival  in  New  York.  The  radio  operators 
keep  close  watch  on  these  ships  for  any  irregu- 
larities in  their  time  of  arrival  and  amount  of 
mail  carried.  For  example,  let  us  say  that  the 
Mauretania  or  the  Majestic  or  the  French  Liner 
Paris  is  listed  to  arrive  on  a  certain  day  with 
ten  thousand  sacks  of  mail.    The  radio  opera- 


tors watch  for  her  and  when  within  range  send 
a  message  to  the  commander  of  the  vessel, 
somewhat  as  follows:  Commander,  Majestic. 
Please  advise  number  sacks  mail  how  much  on 
deck  whether  separated  and  time  you  expect 
reach  quarantine.  The  reply  soon  comes  back: 
Mailboat  President  5165  bags  New  York  City 
starboard  4061  bags  Railroad  port  893  bags 
Parcel  Post  hold  number  three  expect  reach 
quarantine  315  p.m.  Commander,  Majestic. 
From  such  information  the  clerks  in  charge 
are  enabled  to  procure  enough  men  and  to 
dispatch  such  boats  as  are  necessary  to  handle 
that  particular  situation. 

On  the  other  hand,  suppose  that  a  thick  fog 
prevents  the  boat  from  coming  up  the  channel 
to  quarantine  and  she  anchors  off  Ambrose 
Channel  Light-vessel.  It  becomes  necessary 
to  keep  posted  by  radio  as  to  the  exact  move- 
ments of  the  vessel  so  that  no  mailboats  will 
be  dispatched  aimlessly.  If  conditions  permit 
the  mailboat  often  goes  to  Gravesend  Bay,  or 
even  to  Ambrose  in  fog,  gets  the  mail,  and 
returns  to  her  pier;  and  the  mail  is  delivered 
in  Philadelphia,  Pittsburg,  and  Boston  before 


Unloading  the  Mail  from  the  Transatlantic  Liners 


the  ship  docks!  Then  again,  suppose  that  a 
ship  approaches  that  ordinarily  carries  mail, 
but  this  particular  trip  has  none.  It  is  by  radio 
that  such  information  is  obtained,  and  a  trip 
to  quarantine  is  made  unnecessary.  As  an- 
other example,  a  boat  may  be  listed  as  carrying 
five  hundred  sacks  of  mail,  but  stops  at  another 
port  en  route  to  New  York  and  picks  up  perhaps 
fifteen  hundred  sacks.  If  it  were  not  for  the 
radio  reports,  a  small  crew  would  be  dispatched 
which  could  not  handle  such  an  amount  of  mail 
while  in  quarantine. 

The  radio  equipment  on  the  Mailboat 
President  comprises  a  U.  S.  Navy  i-KW  500- 
cycle  spark  transmitter  which  has  a  daylight 
range  of  two  hundred  miles.  The  receiver 
consists  of  a  U.  S.  Navy  short-wave  receiver 
with  detector  and  a  U.  S.  Army  low-frequency 
amplifier  type  SCR-72.  With  this  receiver, 
ships  are  picked  up  two  thousand  miles  east  of 
New  York.  All  communications  between  the 
boat  and  the  pier  are  made  through  the  New 
York  Navy  Radio  Station,  NAH. 

The  important  fact  regarding  the  radio  ser- 
vice is  that  the  operators  who  maintain  the 
watches  are  men  of  experience.  Four  men 
make  up  the  radio  personnel:  J.  Maresca, 
H.  L.  Swart,  O.  N.  Johnson  and  M.  G.  Carter 


CHIEF  OPERATOR  M.  G.  CARTER  AT  THE  KEY 
In  the  radio  room  of  the  Harbor  Mailboat  President 


(operator  in  charge).  All  of  these  men  have 
had  at  least  ten  years',  and  some  fifteen  years', 
experience  in  such  organizations  as  the  Radio 
Corporation  of  America,  International  Radio 
Telegraph  Company,  Signal  Corps,  Navy,  and 
the  Air  Mail  Radio  Service.  Consequently, 
the  work  is  handled  with  uniform  efficiency, 
in  spite  of  the  fact  that  in  the  vicinity  of  New 
York  the  radio  traffic  is  very  heavy. 


MAIL  FROM  THE  OLD  COUNTRY  AND  POINTS  EAST 

Before  the  Manchuria  arrives  in  New  York  Harbor,  the  sacks  are  brought  up  on  deck  ready  to  be  tumbled  down  the 
chutes  when  the  mailboats  come  alongside.    Boat  No.  28  is  shown  receiving  the  mail,  with  No.  14  and  No.  6,  near  by, 

about  to  steam  off  to  take  mail  from  the  Mauretania 


The  Grimes  Circuit  with  Outdoor 
Antenna  and  Counterpoise 

An  Adapted  "Inverse  Duplex"  that  has  Brought  in  California  from  Boston,  Massachusetts 

By  HERBERT  E.  DILL 

I AM  using  apparatus 
built  in  accordance  with 
several  published  descrip- 
tions of  the  David  Grimes 
"  Inverse  Duplex"  three- 
tube  set,  with  an  outdoor 
antenna  and  a  counterpoise, 
tuning  by  means  of  a  stand- 
ard Remler  variocoupler  and 
43-plate  and  23-plate  con- 
densers. 

To  enumerate  the  stations 
listened  to  each  night  and  j 
frequently  well  into  the  morn- 
ing, would   be   literally  to 
copy  the  lists  of  prominent 
broadcasting  stations  one  finds  in  the  radio 
column  of  the  daily  press.    I  am  not  missing 
anything.    Having    completed    this  Grimes 
circuit    to   my   entire   satisfaction,    I  have 
gladdened  the  hearts  of  a  score  of  amateurs  in 
my  community  by  turning  them  loose  without 
restriction  upon  my  junk-pile  of  coils,  con- 


THE  INVERSE  DUPLEX  SET  MADE   BY  THE  AUTHOR 


A  NEAT  JOB 
After  he  had  successfully  made  and  operated  this 
away  all  the  radio  "junk"  he  had  accumulated  in  t 


densers,  variometers,  tuners  and  the  like  with 
which  my  den  and  attic  and  cellar  have  been 
littered  for  two  years.  It  is  such  a  pleasure  to 
have  just  one  outfit  in  the  corner  of  my  den  and 
to  feel  satisfied  with  the  results  it  gives  me. 

My  circuit  diagram  is  like  the  one  pub- 
lished in  Radio  Broadcast  for  April,  except 
that  the  loop  is  replaced  by 
the  apparatus  indicated  in 
(Fig.  1).  Cunningham  tubes, 
Ik,  '  type  300  and  301  are  used; 
Acme  R2  and  R3  and  Chelsea 
transformers;  General  Radio 
variable  condensers  and  po- 
tentiometer; Micadon  fixed 
condensers;  and  Eve  ready 
large  size  block  B  batteries. 
The  storage  battery  is  of  100- 
ampere-hour  capacity,  kept 
/  well  charged  by  means  of  a 
Tungar  rectifier. 

Difficulty  has  been  experi- 
enced in  selecting  rheostats 
for  this  circuit  because  very 
careful  adjustment  of  fila- 
ments seems  necessary.  Ex- 

.   .,    p..,,  cellent  results  were  obtained 

set,  Mr.  Dill  gave  .  ,,       •  , 

he  past  two  years       experimentally  with  separate 


The  Grimes  Circuit  with  Outdoor  Antenna  and  Counterpoise  315 


fig.  1 


MR.  DILL  AT  HIS     JUST  ONE  OUTFIT 


The  secondary  terminals  replace 
the  terminals  of  the  loop  (Fig.  2) 


^  STRAPPING 

controls  improvised  of  resistance  wire  with 
sliding  contacts,  but  these  are  hardly  suitable 
for  neat  panel  mounting. 

A  Remler  variocoupler  is  employed  to  per- 
mit experiments  with  various  types  of  antenna 
ground  and  counterpoise,  but  by  removing  the 
strapping  connecting  two  pairs  of  binding  posts 
on  the  front  panel,  the  Remler  tuner  is  dis- 
connected and  any  type  of  loop  may  be  wired 
directly  to  the  set. 

The  specifications  of  the  original  Grimes  set 
that  appeared  in  the  April  issue  of  Radio 
Broadcast  have  been  carefully  followed,  with 
the  exception  of  the  addition  of  this  vario-coup- 
ler  for  tuning,  and  the  installation  of  the 
separate  filament  controls.  Extraordinary 
success  with  this  Grimes  circuit  is  due  princi- 
pally to  my  excellent  location,  the  use  of  an 
outdoor  antenna,  and  a  counterpoise  calculated 
to  work  perfectly  with  the  set. 


fig.  2 

The  regular  hook-up  of  the  Grimes  "Inverse  Duplex."  The  only  changes  made  by  Mr.  Dill  in  constructing  his  own  set 
are  the  use  of  separate  filament  controls  and  the  antenna  and  counterpoise  arrangement  shown  in  Fig.  1.  A  double-pole, 
double-throw  switch,  cutting  in  a  loop,  might  be  employed  to  advantage — especially  when  it  is  desired  to  receive 

from  local  stations 


Radio  Angling  and  Fisherman's  Luck 


The  Thrill  that  You  Get  When  the  Game  Takes  the  Fly,  and  the  Way  that  You  Feel  When 
It  Doesn't.   The  Inspiration  and  Power  for  Good  of  Broadcasting,  as  Seen  by  One  Clergyman 

By  REV.  H.  F.  HUSE 

In  an  editorial  published  in  a  previous  issue,  we  expressed  the  belief  that  radio  would  prove  a  valuable 
asset  to  the  preacher  in  the  small  town,  in  broadening  his  vision  and  educating  him  in  a  manner  otherwise 
impossible.  The  Rev.  H.  F.  Huse,  Pastor  of  the  United  Baptist  Church  in  Dover-Foxcroft,  Maine  says,  in 
telling  of  the  single-tube  receiving  set  built  by  his  fifteen-year-old  son: 

"One  night,  just  before  starting  for  a  church  service  I  heard  a  beautiful  voice  at  WSB,  Atlanta,  Georgia, 
singing  'The  Heart  that  was  Broken  for  Me.'  It  tuned  my  soul  at  once  for  the  service  I  was  to  lead."  And 
again,  "  I  shall  never  forget  Miss  Bennett's  voice  and  the  words  as  they  went  out  from  WOR,  Newark,  N.  J. 
in  the  transoceanic  broadcasting  concert  of  February  24th  .  .  .  her  wonderful  voice  came  with  a  clear- 
ness that  was  startling.  It  made  one  think  of  the  shepherds  long  ago,  startled,  as  they  were,  in  their  midnight 
vigils  by  voices  out  of  the  air.  I  listened  with  rapt  interest  to  the  greetings  she  spoke  at  the  end  of  the  con- 
cert: 'I  wish  to  express  the  great  privilege  I  feel  has  been  mine  in  singing  to  the  people,  not  only  of  my  own 
country,  but  also  to  the  people  of  France,  Italy,  Belgium,  Switzerland,  and  other  countries  of  Europe.  I 
send  my  most  cordial  greetings  to  all.  .  .  .'  Such,  I  thought,  is  the  spirit  of  America,  the  spirit  of 
Christianity,  the  spirit  of  good  will  the  world  needs.  Moreover,  broadcasting  is  glorified  as  it  scatters  this 
cordial  good  feeling  to  the  ends  of  the  earth." 


■^HE  pleasures  of  radio  are  many  and 
varied.  There  is  first  of  all  the  satis- 
faction which  comes  in  acquiring  the 
information  that  accompanies  all 
this  new  knowledge,  the  energies,  the 
subtleties,  the  mysteries  of  radio.  There  is 
the  wonder  of  this  new  thing,  this  agency  that 
makes  it  physically  possible  for  us  to  hear 
instantaneously  out  of  the  air  the  voice  of  man 
from  the  ends  of  the  earth. 
There  is  the  joy  of  a  new  and 
wholesome  interest  in  life. 
There  is  the  delight  in  the 
friendship  and  fellowship  of 
those  whose  voices  we  hear 
over  the  air,  and  whose  won- 
derful talent  we  so  much  en- 
joy. There  is  the  delight  of 
the  family  circle  gathered 
about  the  radio  set  in  the 
home.  And  not  least  among 
the  pleasures  of  radio  is  the 
angling  for  stations ! 

More  than  once  this  winter 
as  I  have  sat  at  the  receiving 
set,  and  twisted  the  dials  first 
one  way  and  then  another,  in 
trying  to  pick  up  a  station,  I 
have  thought  of  the  similari- 
ties and  the  contrasts  be- 
tween casting  upon  the  radio 


I  TAUGHT  HIM  TO  FISH 


waves  for  a  station  strike,  and  whipping  the 
surfaces  of  pond  and  stream  for  the  sudden 
flash  of  yellow  and  gold,  the  strike  that  means 
the  battle  royal  with  the  red-spots,  and  at  last 
the  pleasure  of  leading  Mr.  Trout  by  the  nose 
or  walking  him  upon  his  tail  into  a  fish  basket 
for  my  lady's  dinner  the  next  day. 

I  taught  my  boy  to  fish  before  he  was  in  his 
teens.  Now  that  he  is  in  his  teens  he  has  come 
back  and  taught  me  radio. 
And  what  a  time  we  have  had 
together,  with  phone  on  ear, 
angling  for  the  stations,  and 
what  a  thrill  as  we  have 
landed  them,  the  little  ones 
and  the  big  ones,  all  the  way 
from  Dover-Foxcroft,  in  the 
heart  of  Maine,  to  Tuinucu, 
Cuba  in  the  South,  and  to 
Kansas  City,  the  home  of 
the  Night  Hawks,  in  the 
West. 

In  angling  for  stations  as  in 
angling  for  trout,  sometimes 
the  game  takes  hold  and 
sometimes  it  doesn't.  When 
the  stations  do  bite,  it  gives 
you  a  thrill  of  pleasure;  and 
when  they  don't,  it  some- 
times tries  your  patience; 
but  a  true  sport  in  radio,  as 


Radio  Angling  and  Fisherman's  Luck 


317 


in  fishing,  takes  things  as  they  come  without 
too  many  complaints. 

I  once  took  a  friend  fishing  to  a  fine  brook 
where  1  had  always  had  good  success.  I 
wished  very  much  for  this  friend  to  see  some  of 
the  beauties  that  I  knew  were  in  its  sequestered 
pools  and  swift  currents.  But  that  day  they 
just  would  not  bite.  And  this  friend  of  mine 
stood  on  the  bank  and  "joshed"  me  for  fair: 
"Trout!  This  brook  never 
saw  a  trout!  Let's  go  up 
in  the  woods  and  fish,  we 
will  get  just  as  many  as  we 
get  here,  and  then  we  won't 
get  our  feet  wet!"  Well, 
I've  talked  the  wonders  of 
radio  to  friends.  I  have 
told  them  the  fine  speeches 
and  splendid  music  we 
hear,  and  how  at  times  the 
box  just  bursts  with  sound ! 
And  then  I  have  invited 
them  in  for  an  evening.  I 
have  seated  them  at  my 
side  and  adjusted  the 
phones  and  then  begun 
angling.  I  have  angled 
and  angled.  But  it  has 
been  an  off  night.  Noth- 
ing doing.  A  few  ripples 
in  the  radio  waves,  but 
nothing  worth  while  com- 
ing in.  I  have  felt  that 
their  thought  of  radio  was 
like  that  of  the  friend  on  the  bank  when  the 
trout  would  not  come  to  the  hook. 

Last  night  I  invited  in  a  friend.  It  was 
Sunday  night  and  I  wished  very  much  to  pick 
up  a  good  church  service.  Like  children  whom 
we  wish  to  speak  their  pieces  before  company, 
and  sometimes  fail  us,  so  at  times  it  is  with 
radio.  Nothing  took  hold  very  well  until  after 
this  friend  had  gone  and  then  with  another 
twist  of  the  dial  I  picked  up  WBZ,  Springfield 
and  heard  a  fine  address  by  the  pastor  of  the 
Methodist  Church  of  that  city! 

I  taught  my  boy  fishing  and  he  has  taught 
me  radio.  When  the  fifteen-year-old  came 
home  and  said:  "  Dad,  we  are  behind  the  times. 
We  have  got  to  have  a  radio  set,"  then  it 
was  time  for  the  boy's  best  chum  to  sit  up  and 
take  notice.  I  made  the  agreement  that  if  he 
would  find  out  how  to  construct  a  set,  and 
convince  me  that  he  could  do  it,  I  would  dig 
down  and  see  if  I  could  find  the  wherewithal 


HE  TAUGHT  ME  RADIO 


to  pay  the  bill.  "Say,  Dad,  you're  the  real 
article!  The  set  is  ours.  I  have  the  parts  we 
need  all  down  on  paper,  their' prices,  and  the 
hook-up."  The  eighth  wonder  of  the  world  is 
the  way  a  boy  in  his  teens  learns  these  new 
things — and  so  quickly!  We  looked  over  the 
list  of  parts  and  prices.  The  total  cost  was 
$40.92. 

In  due  season,  the  box  was  made,  the  parts 
that  we  sent  for  came,  and 
the  set  was  constructed. 
The  antenna  was  hung 
from  the  parsonage  to  the 
church  vestry,  and  I  was 
thankful  indeed  when  this 
job  was  ended,  without 
broken  legs  or  pneumonia 
from  climbing  and  scramb- 
ling over  snow  -  covered 
roofs  with  the  wind  blow- 
ing a  gale  and  the  mercury 
down  below  zero. 

In  radio  as  in  fly  fishing 
the  "hook-ups"  are  as 
varied  as  the  fifty-seven 
orders  of  pickles.  Speak- 
ing of  flies,  Henry  Van 
Dyke  says:   "The  blase 
trout  demands  something 
new,  something  modern. 
It  is  for  this  reason  that  an 
altogether  original  fly,  un- 
heard   of,  startling,  will 
often  do  great  execution  in 
an  over-fished  pool."    So  it  is  with  radio  sets 
and  hook-ups.    Every  now  and  then  it's  the 
new  hook-up  that  seems  to  gather  in  the  stations. 

THE  HOOK-UP  AND  THE  CABINET 

WATCH  the  fisherman,"  says  Henry  Van 
Dyke  again.  "When  he  comes  home 
with  a  full  basket  of  trout  on  his  shoulder,  or  a 
quartet  of  silver  salmon  covered  with  green 
branches  in  the  bottom  of  the  canoe.  His 
face  is  broader  than  it  was  when  he  went  out, 
and  there  is  a  spark  of  triumph  in  his  eye." 
Who  is  there  who  has  not  seen  the  radio  smile 
on  the  face  of  another,  or  felt  the  thrill  in  his 
own  soul  the  morning  after  a  successful  catch? 
What  fisherman  returning  home  at  night  from 
an  all-day  outing  to  brook  or  pond  has  not  been 
greeted  with  the  question:  "What  luck?" 

Our  radio  record  began  Sunday  night,  Febru- 
ary 11,  1923.  Up  to  the  date  of  this  writing 
our  parsonage  radio  creel  has  to  its  credit  the 


3i8 


Radio  Broadcast 


SOMETHING  DOING  IN  THE  AIR 


following  stations  a  thousand  or  more  miles  dis- 
tant: KSD,  PWX,  WDAF,  WDAJ,  WFAW, 
WLAG,  WMC,  WOAW,  WOC,  WOS,  WSB, 
SKW  (Tuinucu,  Cuba),  and  WKAQ.  Con- 
sidering our  location  in  the  heart  of  Maine 
and  upon  the  outer  circle  of  the  area  that 
includes  the  broadcasting  stations,  our  catch 
is  "not  too  bad." 

Reflecting  upon  what  has  come  out  of  the  air 
to  the  listeners,  one  cannot  fail  to  be  impressed 
by  the  wonderful  talent  that  everywhere  in 
America  seems  to  be  the  same — talent  of  speech 
and  song,  orchestra  and  band,  solo  and  chorus. 
Parenthetically,  as  a  preacher,  may  I  say  that 
the  way  in  which  the  broadcasting  stations 
have  so  generously  lent  themselves  to  the 
service  of  the  churches  is  one  of  the  finest  in- 
stances of  religious  cooperation  in  a  big  way 
that  the  Christian  world  has  ever  seen. 

Would  that  there  were  time  and  space  to  tell 
something  about  certain  speeches  and  sermons 
and  music  that  I  have  heard.  It  is  said  that 
Daniel  Webster  put  together  his  famous  reply 
to  Haynes  as  he  fished  along  the  waters  of  a 
New  England  trout  stream.  Be  this  as  it  may, 
the  radio  listener  finds  not  only  mental  change 
and  rest  in  what  comes  to  him  out  of  the  air,  but 


he  finds  inspiration  to  better  thmgs  and  nobler 
effort. 

There  have  been  such  fine  things  from  all 
the  stations  that  it  does  not  seem  fair  to 
mention  one  without  mentioning  all.  But  the 
"big  fish"  that  I  have  missed  someone  else 
catches!  There  stands  out  in  my  memory 
the  "New  York  City  Symphony"  from  WEAF, 
the  "  Albany  Chorus  "  from  WGY,  the  exquisite 
music  from  the  "Waldorf  Astoria"  through 
WJZ,  and  the  selections  by  the  Little  Sym- 
phony Orchestra  via  KDKA.  One  night  just 
before  starting  for  a  church  service  I  heard  a 
beautiful  voice  at  WSB,  Atlanta,  Georgia, 
singing  "The  Heart  That  Was  Broken  for 
Me."  It  tuned  my  soul  at  once  for  the  service 
1  was  to  lead. 

1  shall  never  forget  Miss  Bennett's  voice  and 
words  as  they  went  out  from  WOR,  Newark, 
N.  J.  in  the  transoceanic  broadcasting  concert 
of  February  24th.  It  was  midnight.  The 
transmission  conditions  were  perfect,  and  her 
wonderful  voice  came  in  with  a  clearness  that 
was  startling.  It  made  one  think  of  the  shep- 
herds long  ago,  startled,  as  they  were,  in  their 
midnight  vigil  by  voices  out  of  the  air.  I 
listened  with  rapt  interest  to  the  greetings  she 
spoke  at  the  end  of  the  concert.  "  I  wish  to 
express  the  great  privilege  I  feel  has  been  mine 
in  singing  to  the  people  not  only  of  my  own 
country  but  also  to  the  people  of  France,  Italy, 
Belgium,  Switzerland,  and  the  other  countries 
of  Europe.  I  send  my  most  cordial  greetings 
to  all,  and,  to  the  people  of  Concord,  N.  H., 
my  love." 

Such,  I  thought,  is  the  spirit  of  America, 
the  spirit  of  Christianity,  the  spirit  and  good- 
will the  world  needs.  Moreover,  broadcasting 
is  glorified  as  it  scatters  this  cordial  good  feeling 
to  the  ends  of  the  earth. 


THE  RADIO  ANGLER'S  ROD  AND  REEL 


Crystal  Receivers  are  Well  Worth 

While 

Some  Types  that  are  Simple  to  Put  Together,  Cheap, 
and  of  Value  Both  to  Beginner  and  Confirmed  Enthusiast 

By  ZEH  BOUCK 

Are  you:  interested  in  radio  but  without  any  experience  in  it;  eager  to  enjoy  the  programs  that  fill  the 
air,  and  to  have  the  fun  of  building  or  operating  your  own  receiver;  broke — or  at  least  unwilling  to  pay 
"beaucoup  francs"  for  apparatus  which  you  think  you  cannot  operate,  to  hear  programs  which  you  think 
you  may  not  care  for?  If  so,  get  yourself  a  crystal  set  and  have  a  taste  of  radio  reception  before  tackling 
vacuum-tube  apparatus. 

Or,  if  already  of  the  radio  fraternity,  are  you  building  and  rebuilding,  soldering  and  unsoldering  appa- 
ratus that  passes  in  a  single  week  through  the  throes  of  super-regeneration  and  inverse  duplex?  If  so,  build 
yourself  a  crystal  receiver  as  a  standby  to  tide  you  over  whenever  your  tube  set  is  hors  de  combat,  so  to  speak. 
—The  Editor. 


THE  advent  of  the  dry-cell  tube,  and 
the  general  drop  in  the  price  of 
vacuum-tube  apparatus  has  by  no 
means  sounded  the  knell  of  crystal 
receivers.  The  advancement  in  bulb 
apparatus  has  been  accompanied  by  similar 
strides  in  crystal  equipment,  notably  in  the  de- 
velopment of  synthetic  crystals  which  make 
possible  fairly  consistent  reception  over  mod- 
erately long  distances.  Experienced  operators 
still  recommend  the  purchase  or  construction 
of  crystal  receivers  by  beginners,  as  the  least 
expensive  way  of  mastering  the  fundamentals 
of  tuning,  and  by  the  possessors  of  bulb  appara- 
tus as  a  standby  when  tubes  burn  out  and 
batteries  run  down.  When  bulbs  have  sud- 
denly ceased  to  function,  many  an  interesting 
program  has  been  "saved"  by  requisition- 
ing a  discarded  crystal  set.  Also,  a  familiarity 
with  the  theoretical  and  practical  aspects  of 
crystal  reception  is  of  value  in  the  operation 
and  design  of  many  reflex  sets,  in  which  a 
crystal  is  used  as  the  detector. 

The  crystal  provides  the  simplest  means  of 
detecting  radio  signals,  and  reception  is  ef- 
fected by  imposing  the  incoming  radio-fre- 
quency energy  on  the  circuit  containing  the 
detector,  where  it  is  "rectified."  The  radio 
current,  as  the  reader  is  probably  aware,  is  an 
alternating  current  and  of  so  high  a  frequency 
that,  due  to  a  phenomenon  known  as  re- 
actance, it  cannot  pass  through  the  windings 
of  the  telephone  receivers.  However,  by  means 
of  rectification,  which  the  crystal  accomplishes 


through  its  property  of  passing  electricity  in 
only  one  direction,  half  the  alternating  current 
is  suppressed,  leaving  only  that  part  traveling 
in  one  direction  (a  direct  current),  which 
passes  quite  readily  through  the  receivers. 

There  are  several  ways  in  which  the  radio 
wave  may  be  delivered  to  the  crystal,  but  as 
the  sound  from  an  unamplified  crystal  set  is 
actually  furnished  directly  by  the  power  of 
the  received  wave,  which  is  necessarily  weak, 
only  two  methods,  those  making  the  most  of 
the  weak  radio  impulses,  will  be  considered. 
The  fact  of  direct  power  transformation,  from 
energy  of  radio  frequency  to  energy  of  audio 
frequency,  should  be  constantly  borne  in  mind 
when  building  crystal  apparatus,  to  emphasize 
the  necessity  of  painstaking  construction  tend- 
ing to  eliminate  all  possible  losses.  A  care- 
lessly made  tube  set  may  work,  its  im- 
perfections probably  being  manifest  in^  un- 


FIG.  I 

The  preferred  crystal  circuit,  which,  with  the  addi- 
tion of  the  indicated  condensers,  makes  an  excellent  set 


320 


Radio  Broadcast 


FIG.  2 

An  efficient  and  simpler  circuit 

desirable  sounds  and  lack  of  selectivity;  but 
a  poorly  constructed  crystal  receiver,  incapable 
of  compensating  for  inefficiencies  by  local 
batteries,  will  function  far  below  its  ability. 

The  most  efficient  system  of  crystal  re- 
ception employs  a  loose-  or  variocoupler  in 
the  tuning  circuit.  Fig.  i  indicates  the  man- 
ner in  which  it  is  connected  to  the  detector 
and  phones.  The  coupler,  P  S  may  be  of  the 
type  designated  commercially  as  the  "uni- 
versal" or  "all-wave"  coupler,  or  it  may  be 
a  standard  short-wave  variocoupler  with  the 
secondary  coil  rewound  (if  necessary)  with 
smaller  wire.  Good  variocouplers  can  be  had 
from  reliable  dealers  for  from  $2.75  to  $6;  for 
the  person  who  does  not  care  to  make  his  own- 
apparatus  and  yet  would  be  glad  to  save  money 
by  assembling  bought  parts  himself,  the  pur- 
chase of  a  variocoupler  is  recommended.  Many 
complete  crystal  receivers,  of  course,  are  also 
on  the  market.  They  cost  comparatively  little 
to  buy,  and  nofhing  at  all  to  operate,  since  they 
require  no  bulbs  or  batteries.  However,  a 
home-made  coupler  is  well  within  the  ability 
of  many  experimenters,  and  the  primary  coil 
should  be  wound  with  6oturns  of  any  convenient 
wire  on  a  three-and-a-half-inch  tube,  tapped 
every  sixth  turn.    The  secondary  may  be 


wound  with  72  turns  on  a  three-inch  tube, 
tapping  every  twelfth  turn. 

If  the  fan  already  possesses  a  short-wave 
variocoupler,  but  does  not  care  to  rewind  and 
tap  the  secondary,  a  variometer  may  be 
added  to  the  circuit  at  point  A,  figure  1,  and 
tuning  accomplished  by  means  of  it. 

The  loose-coupler  circuits  are  very  selective, 
and  close  tuning  is  possible  through  variation 
of  the  coupling. 

A  single  coil  of  wire  combining  the  func- 
tions of  both  primary  and  secondary,  is, 
perhaps,  the  more  usual  form  of  inductance 
for  crystal  reception,  but  while  quite  efficient, 
it  necessarily  lacks  the  advantages  gained  by 
variable  coupling.  This  circuit,  Fig.  2,  is 
theoretically  identical  with  that  just  dis- 
cussed, the  turns  of  wire  between  X  and  Z  act- 
ing as  the  primary,  and  those  between  Y  and  Z 
as  the  secondary  coil.  (It  might  be  well  to  note 
here  that  the  functioning  of  many  electrical 
circuits,  particularly  those  associated  with 
wireless,  depends  upon  one  coil  acting  in  the 
capacity  of  two  or  more.) 

The  inductance  coil  in  Fig.  2  may  be  wound 
with  120  turns  of  No.  20  to  No.  28  magnet 
wire,  and  tapped  every  tenth  turn.  Fig.  3 
shows  the  method  of  doubling  up  on  the  taps, 
permitting  the  two  switch  levers  to  cut  in  in- 
dividual amounts  of  wire  from  the  same  taps. 

The  fixed  condenser,  shown  across  the  tele- 
phone receivers,  should  be  of  about  .0015  mi- 
crofarad capacity. 


fig.  3 


Crystal  Receivers  are  Well  Worth  While 


TOP  OF  CUP 


FIG.  4 

A  simple  form  of  crystal  detector  for  home  construction 

The  crystal  sets  just  described  are  well 
adapted  to  the  refinements  associated  with 
audion  equipment,  and  the  addition  of  variable 
condensers  in  the  primary  and  secondary  cir- 
cuits will  add  to  the  selectivity,  and  to  the  ease 
with  which  the  apparatus  may  be  tuned. 
Such  condensers  are  indicated  by  dotted  lines 
in  Fig.  i  and  are  preferably  of  the  43-plate 
(.001  mfd.)  size,  though  the  23-plate  con- 
densers will  be  found  useful.  If  only  one 
condenser  is  available,  it  can  probably  be  used 
to  greater  advantage  across  the  secondary  coil, 
in  the  loose-coupler  circuit,  and  in  the  ground- 
lead  when  the  tuning  coil  is  used.  Whether  or 
not  condensers  are  employed,  apparatus  con- 
structed in  conformity  with  the  directions 
given,  will  respond  to  all  the  broadcast  wave- 
lengths. 

The  detector  itself  may  be  any  one  of 
the  popular  types  on  the  market,  from  the 
simple  moving-bar  design  to  the  more  elaborate 


TO  GROUND 
LEAD 


KMWi 

mmm 

BUZZER 


KEY 


BATT. 


glass-enclosed  instruments.  The  majority  of 
crystal  detectors  are  of  the  cat-whisker  type 
in  which  contact  with  the  crystal  is  effected 
by  means  of  a  fine,  springy  wire  such  as  phos- 
phor-bronze. Such  a  detector  is  easily  built 
by  the  experimenter.  A  simple  design  is  shown 
in  Fig.  4.  The  support  is  a  "U"  shaped  strip 
of  brass  or  other  convenient  metal.  The  ball 
and  the  brass  rod  which  is  passed  through  it 
after  drilling,  may  be  made  from  the  end  of  a 
curtain  rod.  The  cat-whisker  (a  short,  single 
strand  from  a  flexible  lighting  cord,  will 
do  for  this)  is  soldered  to  one  end  of  the  rod, 
while  an  insulating  handle  is  attached  to  the 
other.  The  crystal  may  be  purchased  mounted 
in  a  revolving  cup. 

Another  popular  detector  design  which  is 
particularly  adapted  to  mounting  on  a  vertical 


CARDBOARD 

A 


FIG.  5 
Test  buzzer  connections 


TO  GROUND 
LEAD 


FIG.  6 

Showing  how  a  piece  of 
cardboard  may  be  in- 
serted between  the  arm- 
ature and  spring  contact 
to  improve  the  tone  of 
the  buzzer 


panel  is  that  of  the  rotating  type  made  in  the 
form  of  a  hard-rubber  wheel.  It  contains  a 
sensitive  crystal  with  which  contact  of  the  re- 
quired delicacy  is  obtained  through  gold  or 
other  metallic  dust.  Adjustment  is  effected 
by  turning  and  tapping  the  wheel. 

The  crystal  itself  may  be  galena,  a  natural 
crystal,  or  a  synthetic  product,  which  is  some- 
times more  sensitive  than  the  average  natural 
mineral.  Galena  is  a  double  sulphide  of  lead 
and  silver  along  with  many  unrectifying  im- 
purities— all  in  varying  proportions.  It  is 
not  difficult  to  imitate  the  natural  process  of 
galena  crystallization,  and  the  majority  of  man- 
ufactured crystals  are  merely  an  artificial  ga- 
lena built  up  in  the  most  efficient  proportions 
(from  a  rectifying  standpoint)  with  the  useless 
and  perhaps  undesirable  impurities  eliminated. 

A  crystal  set  is  most  easily  adjusted  for  the 


322 


Radio  Broadcast 


highest  sensitivity  by  means  of  artificial  signals 
from  a  test  buzzer.  The  buzzer,  though  pre- 
ferably of  the  high-frequency  type,  may  be  of 
the  ordinary  door-bell  design,  the  note  of  which 
can  often  be  improved  by  inserting  a  pasteboard 
slip  between  the  armature  and  the  spring  con- 
tact (Fig.  6).  The  sole  connection  between  the 
buzzer  and  receiver  (and  no  connection  at  all 
is  required  when  the  detector  is  correctly  ad- 
justed) is  a  single  wire  running  from  the  sta- 
tionary contact  to  the  ground-lead  (Fig.  4). 
The  detector  should  be  adjusted  while  the  key 
or  push-button  is  down,  and  the  note  of  the 
buzzer  will  be  plainly  audible  in  the  receivers 
when  a  sensitive  adjustment  is  secured. 

The  apparatus  is  preferably  mounted  on 
a  panel  after  the  fashion  of  bulb  sets,  with 
the  detector  placed  on  the  front  in  such  a 
manner  as  to  permit  easy  adjustment.  A  push- 
button may  be  set  flush  in  the  panel  for  operat- 
ing the  buzzer  test,  but  many  enthusiasts 
prefer  a  telegraph  key  on  the  operating  table, 
making  the  buzzer  additionally  useful  for  code 
practice.  Care  should  be  taken  in  the  con- 
struction and  mounting  of  the  instruments, 
in  order  that  the  crystal  receiver  may  be  given 
the  finish  and  appearance  which  it  merits. 

ADDING  AN  AUDION  TO  THE  CRYSTAL  RECEIVER 

THE  crystal  sets  which  have  been  described 
employ  a  tuning  system  that  is  readily 
adaptable  to  bulb  reception,  it  being  merely 
necessary  to  build  up  the  bulb  equipment  as 
an  auxiliary  unit.  The  additional  parts  which 
will  be  required  are:  the  bulb,  A  and  B  bat- 
teries, socket,  rheostat,  grid  condenser  and 
grid  leak,  and  the  plate  variometer.  The 
extra  equipment  should  be  connected  as  shown 
in  Fig.  7,  and  is  hooked  up  to  the  crystal  re- 
ceiver by  connecting  wires  A'  and  B'  to  wires  A 
and  B  respectively  in  Figs.  1  or  2  after  elimin- 
ating the  detector  and  receivers  (the  phones  of 
course  being  transferred  to  the  bulb  circuit). 


The  bulb  unit  for  connection  to  Figure  1  and  2.  This 
will  make  the  crystal  set  into  a  regenerative  receiver 


FIG.  8 


A  combination  audion-crystal  set,  permitting 
instant  change  to  either  form  of  detection 

The  result  will  be  an  efficient  regenerative  re- 
ceiver, which,  if  desired,  may  as  easily  be 
changed  back  to  a  crystal  set. 

Fig.  8  shows  a  combination  crystal-tube  set 
in  which  either  form  of  detection  is  immedi- 
ately available.  When  tube  reception  is  de- 
sired and  the  tube  is  lighted,  it  is  merely  neces- 
sary to  remove  the  cat-whisker  from  its  po- 
sition on  the  crystal.  When  crystal  reception 
is  preferred,  the  current  that  lights  the  bulb  is 
turned  off  and  the  cat-whisker  is  adjusted  to 
rest  lightly  on  the  crystal.  No  switches  are 
required  unless  it  is  desired  to  keep  the  de- 
tector permanently  adjusted,  in  which  case  a 
single-pole  single-throw  switch  may  be  placed 
between  the  crystal  detector  and  the  phones, 
thus  obviating  the  necessity  of  removing  the 
cat-whisker.  The  principle  is  quite  clearly 
indicated  in  Fig.  8,  and  it  may  be  applied  with 
equal  simplicity  to  almost  any  crystal  or  bulb 
circuit  which  you  may  at  present  possess. 

The  crystal  receiver  is  capable  of  remarkable 
results  when  constructed  and  operated  with 
some  degree  of  "finesse" — which,  alas,  is  often 
as  totally  lacking  in  radio  as  in  bridge.  The 
close  of  the  war  found  crystal  receivers  covering 
fifty  to  a  hundred  miles,  on  amateur  power  and 
wavelengths;  and  until  much  more  recently 
they  were  used  almost  exclusively  for  com- 
mercial work  (due  to  patent  complications  on 
bulb  apparatus),  traffic  being  handled  in  many 
instances  over  distances  of  a  thousand  miles! 
Of  course,  you  cannot  expect  to  hear  broad- 
casting stations  a  thousand  miles  away  with 
a  crystal  set,  and  even  fifty-mile  reception  may 
be  considered  exceptional;  but  if  you  live  within 
about  twenty-five  miles  of  a  broadcasting  sta- 
tion, you  should  be  able  to  hear  it  consistently 
and  plainly;  and  the  music  will  come  in  with- 
out the  distortion  so  common  with  sets  employ- 
ing vacuum  tubes. 


Powel  Crosley,  Jr. — "The  Henry  Ford 

of  Radio" 


By  ALVIN  RICHARD  PLOUGH 


THE  other  day  I  visited  two  large 
radio  plants  where  several  hundred 
people  are  daily  engaged  in  turning 
out  radio  apparatus  to  meet  the 
tremendous  demand  for  such  pro- 
ducts. When  I  was  ushered  into  the  office  of 
the  president  of  this  en- 
terprise, I  found  that  he 
was  a  much  younger 
man  than  I  had  expect- 
ed; in  fact  he  confessed 
to  being  thirty-six.  His 
youth  impressed  me 
and  I  marveled  at  his 
ability  to  grasp  big 
problems  and  make 
quick  decisions.  What 
ability  he  has  along  this 
line,  he  says,  has  been 
developed  through  the 
many  and  varied  things 
he  has  done  during  his 
business  career. 

Those  who  knew 
Powel  Crosle'y,  Jr., 
President  of  the  Crosley 
Mfg.  Co.,  as  a  very 
young  man,  refer  to  him 
as  a  "rolling  stone" 
type  of  boy;  but  now 
they  are  glad  to  "  hand 
it  to  him"  as  a  sound 
business  man.  Such  has 
been  the  change  in  sen- 
timent about  the  man 
who  operates  the  radio 
plants  I  visited  in  Cincinnati,  and  who  has  been 
referred  to  as  "the  Henry  Ford  of  radio,"  be- 
cause he  builds  such  large  quantitiesof  good  and 
comparatively  inexpensive  radio  apparatus. 

Mr.  Crosley  told  me  that  it  was  in  1921  that 
he  first  became  interested  in  the  radio  business. 
He  considers  that  he  owes  a  great  deal  to  his 
young  son  for  the  position  that  his  company 
holds  in  the  radio  industry.  It  was  on  Wash- 
ington's Birthday,  just  two  years  ago,  that  his 
boy,  who  was  then  nine  years  old,  wanted  a 


HE  FIRST  BECAME  INTE 
AND  A  HALF 

Now  he  is  head  of  two  radio 


radio  set.  He  took  the  boy  to  the  factory  of 
the  Precision  Equipment  Company,  which  was 
manufacturing  receiving  sets  and  is  one  of  the 
original  licensees  under  the  Armstrong  patent. 
It  was  Mr.  Crosley's  intention  to  buy  an  in- 
expensive set  as  a  toy  for  Powel,  3rd,  but  he 
found  that  the  least  ex- 
pensive one  cost  about 
$130,  which  appeared 
to  him  to  be  too  much  of 
an  investment  for  a 
small  boy's  toy.  The 
insistence  of  the  boy 
was  followed  by  the 
purchase  of  parts  to 
assemble  a  set  and 
notwithstanding  the 
limited  amount  of 
broadcasting  two  years 
ago,  Mr.  Crosley  and 
his  son  became  ardent 
radio  enthusiasts. 

Less  than  two  years 
after  his  first  visit  to 
The  Precision  Equip- 
ment Company's  fac- 
tory, he  purchased  a 
controlling  interest  in 
that  corporation,  which 
is  now  being  operated  as 
a  separate  organization, 
so  that  he  is  now  at  the 
head  of  two  radio  man- 
ufacturing companies! 

The  early  career  of 
Powel  Crosley  is  very 
interesting.  Before  going  to  work,  his  academic 
education  consisted  of  public  school  and  mili- 
tary preparatory  school,  one  year  of  engineering 
work  in  college  and  two  years  at  law  school. 

His  first  job  was  rebuilding  some  old  tele- 
phones during  a  summer  vacation  while  in  the 
public  schools.  This  was  followed  by  work  in 
various  phases  of  the  automobile  business  dur- 
ing summer  vacations  from  college.  During 
his  last  year  in  law  school  he  was  employed  by 
a  large  bill-posting  company  to  acquire  leases 


RESTED  IN  RADIO  TWO 
YEARS  AGO 
manufacturing  companies 


324 


Radio  Broadcast 
W 


MR.  CROSLEY   BROADCASTING  AT  WLW,  CINCINNATI 


on  locations  for  their  signs.  Before  completing 
his  course  in  the  law  school,  he  decided  that 
there  were  opportunities  for  quicker  financial 
returns  than  in  law,  so  he  did  not  complete  his 
course  hut  obtained  a  position  with  a  Cincin- 
nati concern  selling  municipal  bonds.  This 
was  followed  by  the  organization  of  a  small 
company,  of  which  he  was  president,  to  manu- 
facture a  low-priced,  six-cylinder  car.  This 
was  in  the  days  when  there  were  not  more  than 
two  or  three  six-cylinder  cars  on  the  market. 
Although  the  first  car  was  built  and  operated 
successfully,  others  were  never  put  into  pro- 
duction because  of  a  lack  of  sufficient  capital. 

A  few  years  later,  he  took  up  advertising 
and  sales  work,  which  was  followed  by  the  or- 
ganization of  another  automobile  manufactur- 
ing company  to  build  a  very  light  six-cylinder 
car,  and  later,  another  company  to  build  a  light 
four-cylinder  car.  Neither  of  these  companies 
went  into  production  due  to  the  lack  of  suffi- 
cient capital. 

It  was  then,  Mr.  Crosley  says,  that  he  deter- 
mined never  again  to  attempt  to  operate  on 
other  people's  money.    He  had  experienced 


several  disappointments  and  now  started  over 
again,  with  the  intention  of  making  adver- 
tising his  life  work.  He  associated  himself 
with  an  advertising  agency  on  a  drawing  ac- 
count of  only  $20  a  week  in  1914,  and  later 
changed  his  connection  to  another  agency. 
By  1 91 6  he  had  built  up  a  fairly  large  and  pro- 
fitable clientele.  Through  the  service  rendered 
to  one  of  his  clients,  he  was  induced  to  become 
interested  in  the  organization  of  a  company  to 
sell  one  and  later  several  automobile  specialties. 
This  company  he  purchased  outright  in  the 
spring  of  1917,  and  it  has  grown  to  be  one  of 
the  largest  concerns  of  its  kind  in  this  country. 

From  all  this  it  will  be  seen  that  Mr.  Crosley 
has  exceptional  ability  in  business  organization. 
But  it  was  his  realization  of  the  difficulty  of 
obtaining  an  efficient  and  inexpensive  receiving 
set  in  1921 — and  due  also  to  the  fact  that  he 
wanted  something  to  manufacture  which  would 
keep  his  wood-working  plant  in  full  operation 
— that  he  plunged  into  the  radio  business  and 
turned  out  simplified  apparatus  which  could  be 
manufactured  in  large  quantities  and  sold  at 
low  prices. 


Reception  de  Luxe 

By  A.  R.  BOSCOW 


THE  receiving  set  described  in  this 
article  is  of  a  type  created  to  satisfy 
the  ideals  of  the  most  lavish  experi- 
menter and  amateur  who  wants  a 
highly  sensitive  instrument,  respon- 
sive to  the  100-600  meter  wave  band,  embody- 
ing as  simple  a  system  of  control  as  is  consistent 
with  efficient  operation.  While  there  are  no 
radical  departures  from  standard  radio  circuits, 
the  auxiliary  circuits  possess  some  novel  fea- 
tures. 

Before  the  final  assembly  of  this  set,  practi- 
cally every  known  receiving  circuit  had  been 
tried  during  the  previous  twelve  years  that  the 
writer  had  been  experimenting  with  radio. 
This  set,  then,  expresses  what  he  believes  to  be 
the  ultimate  in  receivers  at  the  present  time  on 
the  lower  band  of  wavelengths  and  for  actual 
performance  and  ease  of  control  exceeds  the 
seven-tube  super-heterodyne  operated  at  this 
station  last  year. 


Practically  all  the  stations  heard  have  come 
in  clearly  on  the  loud  speaker,  which  consists 
of  a  Vocarola  attachment  on  a  large  horn,  and 
most  of  the  stations  were  heard  with  consider- 
able volume  on  one  step  of  audio  amplification 
and  quite  a  number  on  the  detector  alone. 
While  the  above  remarks  refer  particularly  to 
broadcast  reception,  it  must  not  be  inferred 
that  this  is  the  set's  only  feature,  for  amateur 
CW  stations  have  been  copied  in  every  district. 

The  set  employs  six  tubes — three  radio- 
frequency  stages,  a  detector,  and  two  audio- 
frequency stages.  The  tuning  circuits  are 
arranged  for  either  loop  or  antenna  reception. 
When  used  with  an  antenna,  the  tuning  ele- 
ments consist  of  a  primary  condenser,  a  vario- 
coupler  and  secondary  condensers.  When  used 
with  a  loop,  plugging  in  on  the  loop  jack  dis- 
connects the  primary  circuit  and  variocoupler, 
leaving  the  secondary  condensers  in  parallel 
with    the   loop  for    tuning.    The  primary 


THE  COMFORTABLE  RETREAT  WHICH  MR.   BOSCOW  BUILT  IN  THE  BASEMENT  OF  HIS  HOUSE 
The  fireplace  is  electric  and  thermostatically  controlled — no  getting 
up  from  the  set  to  put  logs  or  coal  on  during  the  winter  evening! 


326 


Radio  Broadcast 


inductance  is  variable  by  means  of  a  tap 
switch  mounted  on  the  back  panel,  while 
the  secondary  circuit  is  tuned  by  three  con- 
densers (two  variable  and  one  fixed).  The 
shaft  of  the  variocoupler  was  lengthened  to 
include  the  shaft  of  the  three-plate  vernier 
condenser  which  is  thus  made  to  rotate  with 
the  coupling  coil  in  such  a  manner  that  as  the 
coupling  is  increased,  the  vernier  condenser 
capacity  is  decreased,  thus  tending  to  stabilize 
the  resonant  point  of  the  primary  and  second- 
ary circuits  and  helping  to  prevent  detuning 
when  the  coupling  is  changed.  In  parallel 
with  this  condenser  is  the  main  secondary  con- 
denser of  thirteen  plates  which  is  in  turn 
shunted  by  two  .00015  mfd.  condensers  in 
series.  When  the  main  secondary  condenser  is 
set  at  o,  the  secondary  wavelength  is  approxi- 
mately 180  meters  and  increases  to  420  meters 
at  full  scale.  If  now  one  of  the  small  mica  con- 
densers is  cut  out  by  the  switch  provided,  the 
secondary  wavelength  becomes  400  meters  at 
o  and  increases  to  about  600  meters  at  full 
scale.  This  arrangement  gives  a  full  vernier 
effect  with  a  small  variable  condenser  and  still 
provides  a  large  range  of  wavelengths. 

In  case  it  is  desired  to  use  the  tuning  ele- 
ments without  the  radio-frequency  bank,  a 


jack  has  been  provided  which  enables  a  crystal 
or  other  detector  to  be  plugged  in.  The  tuning 
is  accomplished  in  the  usual  manner. 

In  addition  to  the  usual  jack  arrangement 
which  enables  the  signals  to  be  received  on 
either  the  detector  or  the  first  or  second  audio 
amplifiers,  an  additional  jack  has  been  pro- 
vided so  that  an  external  detector  can  be 
plugged  in  on  the  audio-frequency  bank.  This 
jack  in  connection  with  the  one  associated  with 
the  loop  jack  enables  crystal  reception,  utilizing 
the  tuning  elements  with  or  without  audio- 
frequency amplification  and  makes  an  ideal 
arrangement  for  local  reception. 

A  rather  extensive  system  of  voltage  control 
has  been  provided  and  has  proved  to  be  an 
absolute  necessity.  A  0-10  D.  C.  voltmeter 
is  connected  through  a  two-pole,  triple-throw, 
cam-key  switch  to  three  separate  circuits,  one 
of  which  follows  along  on  a  buss  under  the  fila- 
ment rheostats,  to  which  isconnected  sixdouble- 
pole  single-throw  push-button  switches  which 
are  in  turn  connected,  one  to  each  of  the  tube 
socket  terminals.  With  the  key  in  the  proper 
position,  pressing  any  one  of  the  push-button 
switches  shows  the  voltage  on  the  terminals 
of  its  associated  tube.  A  second  circuit  from 
the  key  switch  goes  to  the  A  battery  terminals 


DIAGRAM  OF  THE  RADIO-  AND- 


Reception  De  Luxe 


327 


IT  IS  A  PLEASURE  TO  SEE  A  HOME-MADE  SET  4S  NEATLY  BUILT  AS  THIS 


so  that  the  condition  of  the  storage  battery 
may  be  determined  at  will.  The  third  circuit 
goes  through  a  high  resistance  to  the  B  battery 
terminals  and  enables  a  reading  of  the  plate 
voltage.  The  amount  of  this  resistance  varies 
with  different  makes  of  voltmeters  but  should 
be  of  such  a  value  that  a  scale  multiplier  of  10 
may  be  used.  That  is  to  say  that  when  the 
key  switch  is  thrown  to  the  B  battery  position 
it  is  only  necessary  to  make  a  mental  calcu- 
lation to  get  B  battery  voltage  by  multiplying 
the  scale  reading  by  10.    Such  an  arrangement 


permits  readings  up  to  100  volts  on  a  io-volt 
meter. 

Because  of  the  amount  of  equipment  in  the 
set,  it  was  not  possible  to  have  the  tubes  so 
located  that  their  filaments  could  be  observed 
through  windows  or  holes,  and  an  auxiliary 
indicating  system  was  provided.  Above  each 
rheostat  control  knob  has  been  placed  a  small 
bullseye,  similar  to  those  used  in  the  older  types 
of  telephone  switchboards.  Behind  each  bulls- 
eye  a  2-volt  1 -candle-power  light  has  been 
placed  and  connected  through  a  suitable  re- 


— AUDIO-FREQUENCY  CIRCUITS 


328 


Radio  Broadcast 


& 


THIS  DIAGRAM  SHOWS  THE  VOLTAGE-CONTROL  AND  INDICATING-LIGHT— 


sistance,  wound  on  flat  bakelite  strips,  to  the 
tube  side  of  the  filament  rheostat.  As  the 
filament  of  each  tube  is  turned  on  the  indicating 
lamp  also  lights,  giving  an  attractive  as  well 
as  an  effective  indication  of  the  tubes  in  use. 

The  common  returns  from  these  indicating 
lamps  are  connected  to  a  second  key  switch 
which  is  in  series  with  the  main  filament  leads 
from  the  A  battery  which  provides  three 
switching  combinations: 

1.  -  All  A  battery  current  off. 

2.  — A  battery  on  tube  filament  buss. 


3. — A  battery  on  tube  filament  buss  and  in- 
dicating lamp  circuits. 

These  combinations  make  it  possible  to  oper- 
ate the  set  with  or  without  the  indicating 
lamps  being  lighted. 

Binding  posts  are  provided  for  the  following 
terminals;  antenna,  ground,  A  battery  leads, 
B  battery  leads  and  audio  amplifier  grid  bias, 
the  first  two  being  located  at  the  left  end  of 
the  pane),  while  the  others  are  at  the  right  end. 
The  panel  is  of  bakelite  x  8"  x  38"  and  is 
screwed  to  the  wooden  base  along  the  bottom 


DE  LUXE  IS  THE  WORD  FOR  IT 
Note  the  small  pilot  lights  above  the  six  rheostats,  indicating  whether  the  vacuum  tubes  are  lit  or  not 


Reception  De  Luxe 


OA- 


-CIRCUITS    AS    USED    BY    MR.   BOSCOW    IN    HIS    ELABORATE  RECEIVER 


of  the  panel  and  is  maintained  in  an  upright 
position  by  cast  aluminum  brackets.  This 
panel  and  base  are  arranged  so  that  they  will 
slide  in  and  out  of  the  mahogany  case.  Rubber- 
rimmed  vernier  controls  make  for  easy  manip- 
ulation. 

With  the  exception  of  some  of  the  voltmeter 
leads  the  set  is  wired  throughout  with  No.  14 
copper  wire  covered  with  "spaghetti".  Red 
colored  covering  is  used  for  the  primary  cir- 
cuits, green  for  the  secondary  circuits  (the 
same  as  the  wire  covering  on  the  variocoupler), 
and  yellow  for  the  balance  of  the  radio  and 
audio  frequency  wires.  Black  covering  is 
used  for  the  battery  and  other  circuits. 

The  following  standard  parts  were  used  in 
the  construction  of  the  set: 


Binding  Posts 
Dials 
Rheostats 
Jacks 

Variable  Condensers 

Fixed  Condensers 

Vario-Coupler 

R.  F.  Transformers 

A.  F.  Transformers 

Tubes 

Sockets 

Potentiometer 

Grid  leak  and  Condenser 

Voltmeter 

Vernier  knobs 


EBY 
Chelsea 

Cutler-Hammer 
Pacent 

Wireless  Shop 
Micadons 
Remler 
Murad 
Radio  Corp. 

"  20 1 -A 


Dubilier 

Jewell 

Arkay 


THE  ANTENNA 

THE  antenna  is  of  cage  construction  4 
inches  in  diameter  at  the  outer  end,  taper- 
ing to  two  inches  at  the  lower  end,  with  a 
1  inch,  three-wire  cage  lead-in.  The  flat  top 
has  4  wires  (No.  14  hard-drawn  copper  wire) 
and  is  40  feet  high  at  one  end  and  30  feet  high 
at  the  other.  This  construction  amounts  prac- 
tically to  a  one-wire  antenna,  but  with  the  wire 
in  cage  style  built  on  small  brass  rings  of  in- 
creasing diameter.  The  reason  for  this  kind 
of  antenna  was  an  attempt  to  reduce  the  high- 
frequency  resistance. 

HOW  THE  SET  IS  OPERATED 

THE  A  battery  switch  being  closed,  the 
successive  filaments  are  adjusted  so  that 
the  proper  voltage  is  impressed  on  each  tube. 
This  procedure  is  made  easy  by  the  conven- 
iently placed  voltmeter  push  button  located 
under  its  corresponding  rheostat.  This  meth- 
od of  always  burning  the  filaments  at  con- 
stant potential  insures  consistent  duplication 
of  long-distance  reception  as  well  as  conser- 
ving the  operating  life  of  the  tubes.  The  de- 
tector tube  filament  temperature  is  somewhat 
governed  by  its  plate  voltage  as  well  as  by  the 
position  of  the  stabilizer,  so  that  it  often 


330 


Radio  Broadcast 


happens  that  its  filament  is  operated  above  or 
below  normal  temperature.  This  adjustment 
can  only  be  determined  by  experiment  and 
varies  from  time  to  time.  As  both  the  radio 
and  audio  amplifier  banks  are  connected  to  one 
plate  voltage  buss,  their  plate  potential  is 
the  same  and  appears  to  be  best  at  about 
75  volts.  The  detector  plate  voltage  is  a 
variable  factor,  but  gives  best  results  at  about 
24  volts,  when  amplifier  tubes  are  used  through- 
out. A  grid  bias  of  from  1^  to  3  volts  on  the 
audio-frequency  tubes  prevents  distortion  at 
that  point  as  do  also  the  1 -megohm  grid  leaks 
connected  across  the  output  of  the  audio- 
amplifying  transformers.  As  it  is  essential  for 
best  telephone  reception  to  operate  the  receiver 
without  local  oscillation,  the  stabilizer  is  ad- 
justed until  this  condition  is  obtained.  The 
tuning  now  becomes  nothing  more  than  a 
rough  adjustment  of  the  antenna  circuit  by 
means  of  the  primary  inductance  tap  switch 
in  conjunction  with  the  primary  condenser, 
a  variation  of  coupling  until  a  signal  is  heard, 
then  an  adjustment  of  the  secondary  condenser 
until  maximum  signal  is  obtained.  A  reduc- 
tion of  coupling  is  then  advisable  and  slight 
readjustments  of  the  condensers  until  you  have 
the  signal  as  you  want  it.  With  a  minimum  of 
coupling,  the  receiver  is  most  selective,  and  by 
rotating  the  secondary  condenser  it  is  possible 
to  go  rapidly  from  one  station  to  another  with- 
out interference  between  them  although  they 
may  be  on  only  slightly  different  wavelengths. 
In  this  respect  the  set  is  so  selective  that  it  is 
possible  to  tune  out  a  local  500-watt  station 
on  492  meters  and  bring  in  a  360  meter  station 
1 , 1 00  miles  away.  Due  to  the  radio-frequency 
amplification  there  is  but  little  loss  in  signal 
strength  when  used  with  a  minimum  of  coup- 
ling. 

Some  of  the  distant  broadcasting  stations 


heard  by  the  writer  in  Portland,  Oregon  in- 
clude: 


STATION  LOCATION  AIR  LINE 

MILES 

KLZ  Denver,  Colo.  1035 

KSD  St.  Louis,  Mo.  1810 

KFAF  Denver,  Colo.  1035 

W'DAP  Chicago,  111.  i860 

WCX  Detroit,  Mich.  2100 

WOC  Davenport,  la.  1710 

WSB  Atlanta,  Ga.  2270 

WBAP  Fort  Worth,  Tex.  1680 

WDAF  Kansas  City  Star  1575 

WHAZ  Rensselaer,  Troy,  N.  Y.  2550 

CHCF  Winnipeg  1315 


USING  A  LOOP 

T  F  IT  is  desired  to  use  a  loop,  the  tuning  opera- 
1  tion  consists  simply  of  varying  the  secondary 
condenser  and  the  direction  of  the  loop  until 
the  signal  is  at  a  maximum,  always  keeping 
the  stabilizer  down  just  below  the  oscillating. 
Frequent  voltage  tests  of  both  the  A  and  B  bat- 
teries, as  well  as  of  the  filament  potentials,  are 
essential  to  consistent  and  successful  operation. 

The  "  De  Luxe"  part  of  this  radio  reception 
would  not  be  possible  in  a  cold  garage  or 
among  a  crowd  of  visitors  in  the  living  room, 
for  instance,  so  I  have  given  my  set  an  at- 
tractive and  comfortable  place  to  live  in  by 
building  a  small  room  in  the  basement  with  a 
painted  linoleum  floor  and  paneled  walls  and 
ceilings  of  plaster  board.  Comfort  is  assured 
by  an  electric  fireplace  (thermostatically  con- 
trolled) in  one  corner  of  the  room,  from  the 
top  of  which  appears  the  horn  of  the  loud 
speaker.  Reception  of  a  sort  is  possible  with 
almost  any  kind  of  apparatus,  but  not  the  least 
enjoyable  feature  of  it  consists  in  being  able  to 
sit  in  your  own  cozy  room,  listening  to  St. 
Louis,  Los  Angeles,  or  Calgary,  as  the  notion 
happens  to  strike  you,  and  knowing  that  you 
will  not  be  troubled  with  interference  of  any 
kind. 


Teaching  School  from  a  Broadcasting 

Station 

A  Successful  Test  by  WJZ  and  the  New  York  Board  of  Education 
By  LLOYD  JACQUET 


TO  BE  the  first  group  of  students 
instructed  by  radio  .is  something  of  a 
distinction,  and  it  seems  to  belong  to 
the  class  in  accounting  of  the  Haaren 
High  School,  in  New  York  City. 
At  a  recent  meeting  of  educators,  attended 
by  officials  of  the  Board  of  Education  and 
members  of  the  faculty,  it  was  decided  that  the 
experiment  should  first  be  carried  out  at  the 
Haaren  High  School  under  the  direction  of  Mr. 
R.  Wesley  Burnham,  the  principal,  and  Mr. 
Fred  Siegel  of  the  faculty.    This  was  to  be  the 


first  experiment  made  to  determine  the  feasi- 
bility of  conducting  a  course  of  instruction  by 
radio  in  an  educational  institution  in  New  York 
or  elsewhere. 

Accordingly,  WJZ,  the  Westinghouse  broad- 
casting station,  was  chosen  as  the  station 
through  which  to  conduct  the  experiment, 
sensitive  receiving  sets  were  installed  in  the 
school  room  and  at  headquarters  in  the  Board 
of  Education  Building,  through  the  courtesy 
of  the  Radio  Corporation. 

Voice  amplifiers  were  attached  to  the  receiv- 


A  CLASS  IN  ACCOUNTING  AT  THE  HAAREN  HIGH  SCHOOL  CONDUCTED  BY  RADIO 


332 


Radio  Broadcast 


ing  sets,  so  that  a  large  audience  could  hear 
the  broadcast  simultaneously. 

Promptly  at  1:15  p.  m.  on  a  particular  after- 
noon, the  announcer's  voice  came  through  loud 
and  clear.  At  the  Haaren  High  School,  1 1 
Hubert  Street,  New  York,  the  buzz  of  conver- 
sation stopped  abruptly. 

Dr.  Gustave  Straubenmuller,  Associate  Su- 
perintendent of  the  Board  of  Education,  was 
the  first  speaker. 

"Thirty  pupils  of  the  Haaren  High  School 
sitting  in  a  classroom  in  their  school  building 
will  be  instructed  by  their  teacher  from  the 
WJZ  studio.  This  is  the  first  time  that  pupils 
are  being  instructed  this  way." 

He  was  followed  by  Mr.  Burnham,  Principal 
of  the  High  School.  He  told,  briefly,  of 
the  part-time  and  cooperative  plan  of  educa- 
tion. 

All  the  speeches  were  taken  down  in  short- 
hand by  students  in  the  class  room. 

A  few  seconds  later,  Mr.  H.  W.  Leyenburger, 
head  of  the  Business  Practice  Department,  ad- 
dressed his  class  in  accounting,  and  began  the 
lesson. 

"  I  am  glad  to  greet  my  class  in  Machine 
Calculation  in  this  way,"  said  Mr.  Leyenburger. 
"  In  the  classroom  about  thirty  girls  are  assem- 
bled for  regular  work  in  Machine  Accounting. 
To-day  the  class  room  is  equipped  with  a  loud 
speaker.  Miss  Ella  Hastings,  the  class  teacher, 
is  in  immediate  charge  of  the  work. 

"The  problems  that  will  be  given  involve 
the  four  fundamental  processes:  Addition, 
Subtraction,  Multiplication,  and  Division. 
Now,  if  you  are  ready,  1  will  give  the  first 
problem — 

"Question  No.  1.  Find  Trial  balance," 
said  Mr.  Leyenberger,  whose  voice  was  per- 


fectly registered  in  the  classroom.  "4832.60: 
5392.75;  3570.00 — Answer!" 

In  the  classroom,  the  adding  machines  were 
going  full  speed.  One  question  followed  an- 
other at  a  brief  interval,  until  the  six  problems, 
involving  addition,  percentage,  cost  plus,  di- 
vision, pro  rata,  etc.,  were  all  given. 

A  few  minutes  after  the  lecture  was  com- 
pleted, the  correct  answers  to  the  problems  were 
sent  out  and  received  at  the  Board  of  Educa- 
tion headquarters,  where  they  were  checked 
up  against  the  resultsarrived  at  by  the  students. 
The  overwhelming  correctness  of  the  pupils' 
work  testifies  to  the  faultless  manner  in  which 
radio  waves  carried  the  many  details  of  the 
complicated  problems,  every  one  of  which  had 
to  be  received  perfectly  to  permit  of  a  correct 
solution. 

Principals  of  more  than  twenty-five  city  high 
schools  were  interested  listeners-in  at  head- 
quarters. Far  away  classes  in  business  schools 
were  interested  audiences  also. 

Haaren  High  School  was  not  the  only  one  to 
receive  this  instruction.  Other  high  schools, 
radio  equipped  and  operated  by  the  pupils,  also 
listened-in,  and  the  telephone  brought  to  wait- 
ing officials  reports  of  successful  reception  from 
schools  scattered  all  over  the  city.  This  was 
proof  conclusive  that  hundreds,  even  thousands 
of  pupils  in  many  widely  separated  locations 
can  listen  to  leading  instructors  and  educators 
with  whom  they  otherwise  would  never  come  in 
contact. 

Officials  of  the  Board  of  Education  were  warm 
in  their  praise  of  radio  as  a  factor  in  school  edu- 
cation, and  are  already  discussing  methods  for 
the  immediate  broadening  of  the  service. 

The  advent  of  the  "University  of  the  Air" 
may  be  at  hand. 


A  Tablet  Dedicated  to  the  Radio 

Congregation 


A BRONZE  memorial  tablet,  donated 
by  and  dedicated  to  the  invisible 
radio  congregation  of  Calvary  Epis- 
copal Church,  Pittsburgh,  Pa.,  was 
recently  unveiled  during  the  church 
services  of  that  congregation.  The  Rev. 
Edwin  J.  van  Etten,  pastor  of  the  church  and 
the  first  minister  to  have  his  services  broad- 


casted; Bishop  Alexander  Mann,  of  the  Pitts- 
burgh Episcopal  diocese;  H.  P.  Davis,  repre- 
senting Station  KDKA,  which  station  first 
broadcasted  the  church  services;  and  other 
prominent  Pittsburghers  took  part  in  the  cere- 
mony. 

More  than  4,700  people,  representing  40 
states  of  the  Union,  five  provinces  of  Canada, 


A  Tablet  Dedicated  to  the  Radio  Congregation 


333 


Cuba,  Bermuda,  London, 
and  ships  sailing  the  At- 
lantic Ocean  contributed 
to  the  purchase  of  the 
tablet.  The  contributions 
came  in  every  form  of 
legal  tender — silver  dimes, 
stamps,  nickles,  pennies, 
and  checks.  There  was  a 
surprising  number  of  Can- 
adian dimes.  A  worker 
in  a  Southern  cotton  mill 
sent  Dr.  van  Etten  two 
cotton  socks  with  a 
nickel  in  each  toe.  A 
sailor  sent  120  pennies  he 
had  won  playing  penny 
ante. 

These  contributions 
came  as  a  result  of  Dr. 
van  Etten's  idea  that  the 
radio  congregation  to 
which  he  had  been  preach- 
ing since  January  2,  1921, 
might  like  to  contribute  to 
some  sort  of  memorial. 
Accordingly,  during  the 
reading  of  his  regular 
church  announcements, 
Dr.  van  Etten  told  his  un- 
seen hearers  of  a  plan  to 
have  small  contributions 
from  such  of  them  as  might 
like  to  participate,  the  sum  obtained  to  be  used 
for  a  memorial. 

Response  to  this  idea  was  almost  instan- 
taneous. An  hour  after  the  announcement  was 
broadcasted  contributions  were  received  from 
people  living  in  Pittsburgh.  People  in  the 
vicinity  even  walked  to  the  minister's  home  a 
few  minutes  after  they  had  heard  his  voice  by 
radio  and  left  their  contributions. 

The  first  announcement  was  sent  out  into 
the  ether  one  Sunday  last  February,  and  con- 
tributions have  been  coming  into  Calvary 
Church  ever  since.  The  amount  obtained,  all 
of  it  in  small  contributions,  has  been  used  to 
purchase  a  beautiful  bronze  memorial  tablet. 

The  tablet  is  30  x  26  inches  in  size.  On  it  is 
a  bas  relief  map  of  the  territory  where  Cal- 
vary's church  services  have  been  heard.  The 
map  is  crossed  with  jagged  lines,  indicative  of 
radio  waves  emanating  from  the  radio  station 
at  East  Pittsburgh. 

On  the  tablet  is  the  following  inscription 


THE  DEDICATION  OF  THE  RADIO  TABLET 
Mr.  H.  P.  Davis,  Vice-President  of  the  Westinghouse  Electric  &  Manufacturing 
Company,  is  standing  nearest  the  tablet.  On  his  right  is  the  Rev.  Edwin  J.  van 
Etten,  pastor  of  the  church,  and  believed  to  be  the  first  minister  in  the  world  to 
broadcast  a  sermon.  In  front  of  Dr.  van  Etten  is  Bishop  Alexander  Mann,  of  the 
Episcopal  Diocese  of  Pittsburgh,  and  at  Bishop  Mann's  left  is  Mr.  John  Frazier 
who  installs  the  Westinghouse  Company's  direct  telephone  connections  for  broad- 
casting outside  events 


which  will  undoubtedly  be  read  with  great 
interest  in  the  years  to  come:  "January  2, 
1 92 1,  from  Calvary  Church  for  the  first  time  in 
history  a  church  service  was  broadcasted  by 
radio  wireless  by  the  Westinghouse  Electric 
&  Manufacturing  Company.  This  tablet  was 
placed  (1923)  by  the  Unseen  Congregation." 

The  words  of  H.  P.  Davis,  Vice-President  of 
the  Westinghouse  Company,  made  a  deep 
impression  on  the  visible  audience,  as  no  doubt 
they  did  on  the  unseen  listeners  miles  away. 

"Other  cities  have  memorials,  but  Pitts- 
burgh is  proud  to  be  the  first  to  broadcast  by 
radio  to  the  world  her  own  religious  worship, " 
declared  Mr.  Davis,  "Pittsburgh  is  further 
proud  to  have  as  a  citizen  Rev.  E.  J.  van  Etten, 
rector  of  Calvary,  the  first  minister  in  the  world 
to  catch  the  vision  of  sending  his  message  out 
into  the  highways  and  byways  by  radio. 

"It  is  impossible  for  me  to  express  in  words 
the  great  good  he  has  done  for  thousands  of 
people  by  recognizing  and  using  radio  for  such 


334 


Radio  Broadcast 


JANUARY  Z.I92I 

FROM  CALVARY  CHURCH  •   

i  FOR  WE  FIRST  TIME  IV  HiSTOW  ' 

A  CHURCH  SERVICE  WAS  BROADCASTED  BY  RADIO  WIRELESS 
BY  THE  WESTINCHOUSE  ELECTRIC  &  HANUFACTURING  COMPANY 
THIS  TABLET  WAS  PLACED  (1923)  BY  THE  UNSEEN  CONGREGATION. 


TABLET  AT  CALVARY  CHURCH,  PITTSBURGH 
More  than  4,700  people,  scattered  all  over  North  Amer- 
ica, contributed  small  amounts  toward  this  memorial 

a  noble  purpose.  It  has  enabled  him  to  reach 
and  to  console  the  sick  and  the  shut-ins  all 
over  this  continent,  without  detracting  one 
iota  from  the  excellent  work  he  is  doing  in  his 
own  parish.  Mr.  van  Etten  has  reached  suf- 
fering people  who  have  been  cut  off  from 
church  services  for  years  and  who  never  ex- 
pected to  hear  church  services  again.  His 
initiative  has  made  possible  this  splendid  me- 
morial gift  from  which  I  have  just  lifted  the 
American  flag,  which  Calvary  always  will 
point  to  with  pride. 

"  1  see  in  the  future  constant  pilgrimages 
making  way  to  this  spot  where  we  stand  to 
view  this  tablet  and  to  read  these  words.  You 
who  gather  about  this  church  to-night  are  the 
first  to  make  that  pilgrimage. 

"  Pittsburgh  is  proud  to  be  the  home  of  Cal- 
vary Church,  the  first  church  in  the  world  to 
extend  by  radio  its  services  beyond  its  own 
parish,  into  every  corner  in  the  country,  to  an 


audience  which  in  numbers,  in  denominations, 
and  in  location  never  before  has  been  compre- 
hended. 

"This  testimonial  of  appreciation  has  come 
back  to  Calvary  from  the  unseen  congregation. 
The  bronze  tablet,  for  which  contributions  have 
come  from  more  than  40  different  states,  from 
five  Canadian  provinces,  from  ships  at  sea, 
from  England,  Mexico,  Honduras,  and  Cuba, 
is  placed  to  commemorate  in  a  prominent  and 
permanent  way  the  pioneering  done  by  Cal- 
vary Church  of  Pittsburgh  and  Station  KDKA 
in  the  broadcasting  of  church  services." 

Mr.  Davis's  talk  and  the  singing  of  one  verse 
of  "America"  by  the  surpliced  choir  and  the 
audience,  and  Dr.  van  Etten's  brief  benediction 
all  were  broadcasted  via  the  microphone  which 
stood  on  a  tripod  near  the  speakers.  Even 
the  noise  of  the  passing  street  cars  and  whirring 
auto  engines  could  be  heard  by  the  radio 
listeners  hundreds  of  miles  away. 

Dr.  van  Etten,  who  has  preached  nearly 
every  Sunday  to  his  radio  congregation  since 
his  first  sermon  in  1921,  declares  the  radio 
possibilities  for  the  clergy  to  do  good  work  are 
boundless. 

"  Mission  churches  without  a  parson  may 
have  the  best  religious  services,"  he  said. 
"  Hospital  wards  have  been  equipped.  Our 
parish  is  doing  organized  work  by  wireless. 
We  have  several  receiving  sets.  The  church 
home  hears  our  services  through  one  of  the 
sets.  The  invalids  of  the  parish  are  enjoying 
the  use  of  two  others.  Outside  our  own  parish 
family,  groups  all  over  the  country  gather  at 
the  library  table  for  a  wireless  Sunday  night 
worship.  Thousands  can  have  services  who 
never  had  the  chance  before.  I  feel  radio  is 
a  wonderful  boon  to  the  church." 


All  Boy  Scouts,  Attention! 


RADIO  BROADCAST  is  holding  a  contest,  ending  July  31, 1.92  3,  to  determine  WHAT  BOY 
SCOUT  TROOP  HAS  DONE  OR  IS  DOING  THE  MOST  WITH  RADIO. 


Prizes  for  Winning  Articles 

FIRST  PRIZE:    CROSLEY  MODEL  X  4-TUBE  RECEIVER. 

This  receiver,  which  may  be  used  with  dry-cell  tubes  if  desired,  consists  of  detector,  one  stage  of 
tuned  radio-frequency  and  two  stages  of  audio-frequency  amplification.  (Advertised  in  Radio 
Broadcast). 

SECOND  PRIZE:    MUSIC  MASTER  LOUD  SPEAKER. 

This  is  the  new  loud  speaker  made  by  the  General  Radio  Corporation.     {A  picture  and  description 

Radio  Broadcast). 


of  it  appear  in  the  advertising  pages  of 

THIRD    PRIZE:  THREE 
The  IVD-ll  is  the  well-known  dry- 
Corporation.    (Filament  voltage  1.5, 
of  the  third  pri^e  may  have  UV-igg's 

A  YEAR'S  SUBSCRIPTION  TO 
given  as  prices  for  the  ten  next  best 

These  pri(es  will  be  awarded  to 
troop  may  delegate  one  of  its  members  to 


IVD-ll  VACUUM  TUBES, 
cell  tube  manufactured  for  the  Radio 
plate  voltage  22]A — 45).    The  winner 
or  UV-201-A' s  if  he  prefers. 


"RADIO  BROADCAST" 
contributions  in  this  contest. 


will  be 


troops,  not  to  individuals,  although  any 
prepare  the  story. 


Rules  of  the  Contest 


/.  Articles  must  be  true  accounts  of  radio  with  relation  to  your  particular  troop:  what  you  have  done,  or  are 
doing,  or  both. 

2.  Every  article  must  be  written  by  a  Scout  or  by  more  than  one  Scout  belonging  to  one  troop. 

3.  Articles  should  be  between  500  and  1000  words  long. 

4.  Good  photographs  to  illustrate  the  article  will  count  50%  in  judging  contributions. 

5.  Typewritten  manuscript,  double-spaced,  is  desired,  though  not  required. 

6.  Address  contributions  to  Scout  Contest,  Radio  Broadcast,  Doubleday,  Page  &  Company,  Garden  City,  N.  Y. 


Scouts  have  done  splendid  work  in  maintaining  communication  by  radio  in  time  of  floods  and  disaster,  in 
copying  and  spreading  the  market  reports  transmitted  by  the  government  Farm  Bureaus,  in  training  themselves 
along  mechanical  and  electrical  lines,  and,  in  short,  in  using  radio  as  a  part  of  scout  work  in  a  way  consistent 
with  the  best  traditions  of  scouting.  What  have  you  to  tell  of  your  troop' s  past  or  present  activities?  Get  your 
scribes  and  photographers  under  way  with  that  story  which  will  put  in  a  strong  bid  for  first  pri^e.  How  would 
a  receiver  with  three  stages  of  amplification  go  in  your  troop? 

The  winners  will  be  announced  in  the  September  number,  and  at  least  one  of  the  three  best  articles  will  ap- 
pear in  that  issue. 


Sets  for  the  Great  Outdoors 


By  A.  HENRY 

This  article,  prepared  for  Radio  Broadcast  by  a  radio  man  of  wide  experience  should  be  interesting  and 
helpful  to  all  of  you  who  are  contemplating  trips  into  the  country  this  summer  or  autumn.  Mr.  Henry  has 
used  radio  receivers  in  automobiles  and  small  boats  for  several  years,  and  his  remarks  on  various  types  of 
bought  receiving  sets  and  their  use  may  assist  you  in  choosing  a  good  outfit  for  yourself.  A  receiver  on 
your  vacation  will  be  a  source  of  great  pleasure  if  it  is  kept  in  working  order,  but  it  will  only  be  an  extra 
package  to  lug  around  if  it  "goes  bad." 

The  author  has  just  returned  from  a  thousand-mile  automobile  trip  and  some  of  the  difficulties  encoun- 
tered are  still  fresh  in  his  mind.  He  has  prepared  what  we  think  is  a  very  practical  and  helpful  article. — 
The  Editor. 


YOUR  vacation  this  year,  and  your 
shorter  trips  into  the  country,  may 
be  made  much  more  enjoyable  if 
you  arrange  to  take  a  good  receiv- 
ing set  with  you.  Receivers  for 
any  kind  of  use  and  suited  to  almost  any 
pocket-book  are  now  available,  so  that  there  is 
no  reason  why — even  though  you  be  in  the 
woods  of  Maine  or  the  mountains  of  California 
—the  World  Series  baseball  scores,  music,  and 
other  entertainment  should  not  come  to  you 
in  the  evening. 

With  most  of  us,  the  cost  of  a  radio  receiver 
is  a  rather  important  item,  and  for  this  reason  it 
may  be  well  to  consider  several  types,  ranging  in 
price  from  a  few  dollars  to  two  hundred  or  more. 


A  PLACE  for  everything 
Is  found  in  this  neat  carrying  case. 
Interior  view  of  the  set  shown  above 


A  PORTABLE  RECEIVER 

That  includes  everything  from  the  antenna 
to  a  spare  tube.  It  was  developed  by  Lyon 
and  Healy,  the  Chicago  music  company 

The  single-tube  receivers  that  have  furnished 
so  much  enjoyment  in  your  homes  during  the 
last  few  months  will  serve  equally  well  on  a 
camping  or  boat  trip,  provided,  of  course,  there 
is  room  enough  to  erect  a  single-wire  antenna. 
Where  a  single  tube  is  used  there  are  only  two 
circuits  that  will  prove  satisfactory  over  any 
distance.  They  are  the  single-  or  double-circuit 
regenerative  outfits  and  the  single-tube  reflex 
with  a  crystal  detector.  There  is  little  need  in 
dwelling  upon  the  use  of  the  home-made  re- 
ceiver, for  any  one  who  is  ingenious  enough  to 
have  made  and  operated  one,  will  have  little 
difficulty  in  shifting  it  from  the  house  to  the 
automobile  or  boat. 

Realizing  the  great  demand  there  would  be 
for  portable  receivers  this  summer,  some  of  the 
commercial  companies  have  developed  compact 


Sets  for  the  Great  Outdoors 


337 


machines  that  will  work  very  satisfactorily  over 
comparatively  long  distances.  One  receiver  of 
this  nature  is  the  "  Aeriola  Sr.,"  which  is  made 
up  with  a  tube  that  operates  from  a  single  dry 
cell  and  one  small  "B"  battery.  This  receiver, 
along  with  a  complete  antenna  equipment,  tube, 
and  batteries  may  be  had  for  §75.  It  is  quite 
small  and  may  be  tucked  away  almost  any 
place  in  the  camping  outfit  and  may  be  set  up  in 
a  few  minutes.  A  single-wire  aerial  stretched 
from  a  tree  to  your  automobile  from  50  to  75 
feet  and  a  few  feet  above  the  ground  should 
receive  at  night  over  distances  of  five  hundred 
miles. 

Another  and  equally  satisfactory  portable  re- 
ceiver is  the  new  outfit  made  by  the  Colin  B. 
Kennedy  Company.    Where  this  outfit  is  used 
with  dry-cell  tubes,  it  is  en- 
tirely  self-contained  with 
the  exception  of  the  antenna. 
It  comes  in  a  cabinet  15"  x 
7 \"  x  7"  and  weighs  seven- 
teen pounds.  It  sells  for  $75 
with   tube,   dry  batteries, 
phones,  and  carrying  case. 

Another  very  compact 
portable  receiver  designed 
for  use  with  two  tubes,  hav- 
ing the  A  and  B  batteries 
right  in  the  carrying  case,  is 
known  as  the  Radiola  II.  It 
is  manufactured  by  the 
General  Electric  Company 
and  sells  without  antenna 
equipment  for  $97. 50.  With 
this  outfit,  it  is  necessary  to 
put  up  the  antenna  and 
make  some  sort  of  a  ground 
connection.  The  necessary 
equipment  for  this  may  be 
procured  for  a  dollar  or  so. 
All  the  other  wiring  has 
been  taken  care  of  by  the 
manufacturers. 

A  fourth  outfit,  and  one 
which  we  believe  will  be 
found  popular  during  the 
summer,  has  been  made  up 
by  the  firm  cf  Lyon  &  Healy 
in  Chicago.  It  incorporates 
a  single  tube  regenerative 
receiver  with  the  necessary 
batteries  for  operating  it,  a 
spare  vacuum  tube,  and  a 
complete    antenna  equip- 


ment provided  with  shackles  and  ropes  which 
make  i'L  possible  to  erect  the  antenna  in  a  jiffy. 
All  the  equipment  is  placed  in  a  well  made 
containing  case.  This  outfit  sells  for  the 
reasonable  price  of  $100. 

Where  the  antenna  and  ground  connections 
would  be  inconvenient,  it  is  possible  to  use 
some  form  of  loop  receiver.  We  have  secured 
some  very  satisfactory  results  in  operating  a 
three-tube  De  Forest  reflex  outfit,  using  tele- 
phone receivers.  This  outfit  may  be  had  com- 
plete with  UV-199  tubes,  the  necessary  adapters, 
"A"  and  "B"  batteries,  and  a  pair  of  telephones, 
for  approximately  Si 62.  Where  a  loud  speaker 
is  desired,  it  is  possible  to  use  this  De  Forest 
outfit  with  an  antenna  from  25  to  50  feet  long. 
No  ground  connection  is  necessary.    In  this 


ON  TOP  OF  THE  WORLD  IN  THE  CUMBERLAND  MOUNTAINS 
Louis  G.  Pacent,  the  radio  manufacturer,  C.  F.  Goudy,  Instructor 


of  Mechanical  Engineering,  Pratt  Institute,  and  the  author  enter- 
tained a  few  Shriners  on  their  way  to  the  Washington  gathering 


338 


Radio  Broadcast 


THE  COLIN   B.   KENNEDY  PORTABLE 

case,  however,  instead  of  using  UV-199  tubes, 
the  201-A's  are  found  more  satisfactory  and 
may  be  operated  from  the  automobile  or  boat 
storage  battery  as  described  a  little  farther  on. 

The  De  Forest  four-tube  receiver,  called  the 
D-10,  may  be  used  to  operate  a  loud  speaker 
with  UV-199  tubes  over  comparatively  long 
distances  without  an  antenna,  and  inasmuch  as 
the  A  and  B  batteries  may  be  carried  in  the 
lower  part  of  the  receiver  cabinet,  this  outfit  is 
very  practical  for  traveling.  The  necessary 
equipment,  including  the  loud  speaker,  a  good 
pair  of  telephones,  and  a  carrying  strap  may 
be  had  for  approximately  $225. 

Where  it  is  desired  to  operate  without  an- 
tenna, ground,  or  loop,  the  new  four-tube 
Grebe  receiver  may  be  used.  In  this  case,  a 
single  wire  some  twenty  feet  long,  thrown  over 
the  top  of  the  car  or  across  the  roof  of  the  deck- 
house on  a  boat,  will  work  very  satisfactorily 
and  collect  energy  enough  for  the  operation  of 
a  loud  speaker  over  comparatively  long  dis- 
tances. Where  the  auto  or  boat  battery  is 
used,  it  is  already  grounded  to  some  part  of  the 
motor  and  the  single  wire  is  all  that  is  necessary. 
It  may  be  run  around  an  auto  top  or  up  the 
mast  on  a  boat. 

ENTERTAINING  A  CROWD 

LOUD  speaker  operation,  as  we  have  con- 
u  sidered  it  so  far,  is  not  of  the  character 
that  will  entertain  a  whole  community  or  sup- 
ply music  with  volume  enough  for  dancing  in 
the  open.  This  may  be  accomplished,  how- 
ever, if  any  good  power  amplifier  is  used.  The 
Western  Electric  or  Magnavox  three-tube 
amplifier,  for  example,  used  with  UV-201-A 
tubes  operated  from  a  storage  battery  and  one 


105-volt  B  battery  and  a  22^- 
volt  B  battery  in  series  will  be 
enough  to  supply  music  for  the 
entertainment  of  rather  large 
audiences. 

It  is  quite  likely  that  most 
vacationists  will  find  that  re- 
ceivers operated  from  dry  cells 
will  suit  their  purpose  best  and 
there  is  little  use  in  discussing 
receivers  of  this  character,  for 
those  of  standard  make  are  sup- 
plied with  complete  instructions. 
But  where  the  automobile  or 
boat  storage  battery  is  to  be 
used  to  light  the  filaments,  a 
certain  amount  of  care  must  be 
exercised  to  prevent  the  filaments  being  burned 
out,  especially  while  you  are  in  some  place 
were  new  vacuum  tubes  cannot  be  obtained. 
In  an  automobile,  plugging  in  on  the  storage 
battery  is  a  simple  matter.  Most  machines 
are  provided  with  a  dash  light  and  the  wiring 
system  is  made  to  accommodate  either  single- 
or  double-contact  bayonet-based  lamps.  By 
taking  the  lamp  out  of  your  dash  socket  you  can 
determine  the  character  of  wiring  in  your  ma- 
chine. Having  found  this  out,  it  is  but  neces- 
sary for  you  to  call  upon  an  automobile  acces- 
sory store  and  procure  an  attachment  plug  from 
which  a  pair  of  wires  may  be  led  to  supply  the 
current  for  operating  your  filaments.  In  con- 
necting these  attachment  plugs,  care  should  be 
taken  to  have  all  the  contacts  firm.  A  loose 
contact  will  cause  a  great  deal  of  noise.  Be- 
fore placing  the  wire  in  the  attachment  plug, 
it  is  a  good  plan  to  solder  the  end  of  each 
wire  so  as  to  make  it  a  solid  mass  rather 
than  a  number  of  strands.  By  so  doing  the 
contact  screw  in  the  attachment  plug  will  not 
cut  through  the  thin  wires  and  there  is  very 
much  less  possibility  of  a  short  circuit.  The 
most  suitable  wire  for  work  of  this  sort  is  calleC 


SINGLE  OR  DOUBLE  CONTACT 
That's  the  question  when  you  wish  to  use  your 
auto  storage  battery  to  light  your  filaments. 
With  one  of  these  little  adaptors  plugged  in 
your  dash  socket  you  can  get  "juice"  in  a  jiffy 


Sets  for  the  Great  Outdoors 


339 


double-conductor  Rome  super-service  cord. 
Number  16  will  be  found  satisfactory.  The 
wire  in  this  case  is  entirely  rubber-covered  and 
it  will  stand  a  great  deal  of  abuse  and  twisting 
without  breaking.  For  its  entire  length 
throughout  the  cord,  one  wire  is  covered  with  a 
cotton  material  of  a  different  color  from  the 
other,  making  it  an  easy  matter  to  connect  the 
positive  side  of  the  battery  where  it  should  be 
connected. 

Another  method  of  using  the  automobile 
battery — although  not  quite  so  convenient  as 
the  plug  cord  attachment — is  using  two  large 
clips  fastened  to  the  end  of  the  battery  leads, 
which  in  turn  are  snapped  on  to  the  terminals 
of  the  battery.  This  arrangement,  however, 
makes  it  necessary  to  lift  the  floor  boards  every 
time  a  connection  is  desired  and  on  the  road 
frequently  results  in  the  dirtying  of  clothes  and 
the  possibility  of  ruining  them  with  the  acid 
deposit  found  on  an  automobile  battery. 
Great  care  should  be  taken  to  prevent  any 
possible  short  circuits.  The  free  ends  of  the 
leads  from  the  storage  battery  should  be  kept 
well  separated  while  the  attachment  plug  is  in 
the  socket,  unless  they  are  connected  to  bind- 
ing posts  on  the  receiver. 

In  the  event  that  ordinary  lamp  cord  is  used 
instead  of  this  cord,  the  matter  of  determining 
the  polarity  of  the  storage  battery  is  a  com- 

IT  IS  WELL  TO  SOLDER  THE  ENDS 

When  flexible  cable  is  used,  to  prevent  the  binding 
screws  in  the  plug  from  cutting  the  individual  strands 


paratively  simple  matter.  It  is  but  necessary 
to  stick  the  leads  into  a  raw  potato  and  it  will 
be  found  that  a  greenish  deposit  will  soon  ap- 
pear around  the  positive  lead. 

don't  burn  out  your  tubes 

ASAFEmethod  of  preservingthe  filaments  is 
to  connect  an  ordinary  25-watt  no-volt 
lamp  in  series  with  them.  Where  this  is  done 
and  the  B  battery  leads  happen  to  touch  the 
A  battery  terminals,  the  filaments  will  not  be 
burned  out.  This  precaution  is  especially  rec- 
ommended where  an  attempt  is  made  to 
operate  the  receiver  from  the  automobile  or 
boat  battery  while  in  motion.  As  a  matter  of 
fact,  the  use  of  the  set  under  these  circum- 
stances is  not  recommended. 

Some  of  the  little  stunts  that  will  be  found 
invaluable  on  the  camping  trip  are  shown  in 
the  accompanying  illustration.  Others  will 
suggest  themselves  to  you  as  you  prepare  for 
your  trip.  There  is  one  word  of  caution  that 
I  would  have  you  remember,  for  I  believe  it 
will  offset  the  possibility  of  carrying  a  receiver 
that  will  be  out  of  business  when  you  want 
most  to  use  it:  be  sure  that  the  receiver  is  packed 
well.  Do  not  leave  it  out  until  the  last  minute 
and  then  stick  it  wherever  it  will  go,  because 
the  vibration  is  hard  on  soldered  connections 
and  they  are  likely  to  part.  The  safest  place 
to  carry  vacuum  tubes  is  in  their  sockets,  but 
where  the  receiver  is  of  the  cabinet  variety 
some  soft  paper  or  cloth  should  be  put  in  on 
top  of  them.  This  should  be  removed  when 
the  set  is  in  operation. 

If  you  are  not  the  owner  of  a  set  at  present,  in 
deciding  upon  the  receiver  to  take  with  you  it 
is  well  to  remember  that  when  your  vacation 
is  over  you  will  want  a  good  receiver  in  your 
home  and  it  is  well  to  consider,  in  purchasing 
the  receiver,  the  amount  of  home  use  you  are 
likely  to  require  from  it. 

Another  thing  that  will  add  to  the  pleasure  of 
your  trip  is  a  camera.  Photographs  of  your 
party  entertaining  people  where  radio  was 
previously  unknown,  for  instance,  will  be  a 
source  of  pleasure  to  you,  not  only  now  but  in 
the  years  to  come. 


A  CALL  BOOK  FOR  THE  AMATEUR 

All  the  active  amateur  and  broadcasting  stations  in  the  U.  S.  and  Canada  are 
contained  in  the  fourth  edition  of  the  Amateur  Radio  Call  Book,  published 
by  the  Radio  Directory  &  Publishing  Co.,  45  Vesey  St.,  New  York.  A  large 
two-color  map,  suitable  for  mounting  on  cardboard,  is  an  added  feature. 


A  Practical  Super-Heterodyne 

with  199's 

By  WALTER  VAN  B.  ROBERTS 

Princeton  University 


RADIO  fans  all  over  the  country  are 
constantly  experimenting  with 
"new  hook-ups,"  and  the  papers 
and  magazines  are  full  of  circuit 
k  diagrams.  One  might  think  that 
there  were  a  vast  number  of  really  different 
methods  of  radio  reception.  Actually  how- 
ever, there  are  only  a  few  fundamentally  dif- 
ferent schemes  in  use, 
and  all  circuits  are 
based  on  these.  For 
example,  out  of  the 
fundamental  idea  of 
regeneration,  there 
have  sprung  hundreds 
of  apparently  different 
regenerative  receiving 
circuits.  These  may 
differ  in  ease  of  adjust- 
ment, but,  with  the 
same  tube  and  antenna, 
any  type  of  regenerative 
receiver,  if  properly 
built,  will  be  exactly  as 
sensitive  as  any  other 
type.  Hence,  if  you 
have  a  good  regenera- 
tive receiver  and  are 
not  satisfied  with  its 
sensitivity,  there  is  no 
use  wasting  time  and 
money  trying  other 
regenerative  circuits.  Rather,  improve  the  one 
you  have. 

Nearly  all  circuits  in  use  at  present  are  based 
upon  the  following  fundamentally  different 
schemes  for  increasing  the  strength  of  the 
signals: 

(1)  Regeneration 

(2)  Super-regeneration 

(3)  Radio  frequency  \  (a)  untuned 
amplification                          }    (b)  tuned 

(4)  Super-heterodyne 

Without  discussing  these  methods  at  length, 
their  limitations  and  drawbacks  may  be  pointed 
out  briefly: 


THE  ULTIMATE  RECEIVER 


In  this  comprehensive  article,  Mr.  Roberts 
discloses  the  advantages  of  the  super-hetero- 
dyne in  which  the  intermediate-frequency 
circuit  may  be  either  of  the  untuned-  or  tuned- 
transformer  variety  and  in  which  neutrodyn- 
ing  and  reflexing  may  be  employed  to  ad- 
vantage. 

This  is  not  the  receiver  [for  the  novice  to 
attempt  building,  because  a  certain  amount  of 
familiarity  with  radio-frequency  circuits  is 
necessary. 

During  our  recent  visit  to  Princeton  Uni- 
versity, we  inspected  and  operated,  with  Mt. 
Roberts,  the  completed  receiver.  To  say 
that  it  tunes  sharply  would  be  putting  it 
mildly,  while  its  ease  of  operation  is  remark- 
able. There  is  a  growing  respect  for  the  super- 
heterodyne, and  we  shall  welcome  informa- 
tion from  those  who  experiment  with  the 
intermediate-frequency  transformers  along 
the  lines  outlined  in  this  article. — The  Editor. 


(1)  Regenerative  circuits,  when  allowed  to 
oscillate,  annoy  the  neighbors,  and  the  sensi- 
tivity obtainable  without  loss  of  quality  is  not 
great  enough  for  the  satisfactory  use  of  a  loop 
antenna. 

(2)  Super-regenerative  circuits  are  not  very 
selective,  and  are  noisy  if  the  signals  are  weak. 

(3)  Untuned  radio-frequency  amplification 
with  the  present  type 
of  tubes  is  not  entirely 
satisfactory  (in  the 
writer's  opinion)  due 
principally  to  una- 
voidable transformer 


losses. 

Tuned  radio-fre- 
quency amplification, 
with  regeneration  pre- 
vented by  the  "neu- 
trodyne"  principle, 
seems  very  satisfac- 
tory, except  that  for 
great  sensitivity  tun- 
ing becomes  difficult 
on  account  of  the  large 
number  of  circuits  that 
have  to  be  tuned. 

(4)  The  super- 
heterodyne method 
seems  to  have  no  in- 
herent drawbacks  or 
limitations.  To  justify 
this  rather  sweeping  statement,  let  us  consider 
briefly  the  three  most  important  features  in  any 
receiving  set. 

First,  sensitivity:  here  nature,  in  the  form  of 
"static,"  spark  sets  and  other  interfering  radio 
transmitters,  imposes  a  limit  to  the  useful 
sensitivity  of  any  receiving  set.  For  if  the 
static  and  other  interference  coming  in  on  the 
same  wavelengths  as  the  signal  are  stronger 
than  the  signal  itself,  then  no  amount  of  sensi- 
tivity will  be  of  any  use,  for  the  undesired 
noises  will  always  be  louder  than  the  signals. 
Thus,  there  is  no  sense  in  possessing  a  radio 
receiver  that  is  any  more  sensitive  than  enough 


A  Practical  Super-Heterodyne  with  190/s 


341 


FRONT  VIEW  OF  SUCCESSFUL  SIX-TUBE  SUPER-HETERODYNE  BUILT  BY  MR.  ROBERTS 
The  set  uses  two  stages  of  intermediate-frequency  amplification  coupled  by  R.  C.  A.  long-wave  transformers,  and  one 
stage  of  A.  F.  amplification.    The  rheostat  in  upper  left-hand  corner  of  panel  controls  the  volume,  the  left-hand  con- 
denser tunes  the  loop,  and  the  right-hand  condenser  tunes  the  heterodyne 


to  bring  in  static  and  other  noises  with  annoying 
loudness  on  the  days  when  the  interference  is 
minimum.  Any  further  increase  in  range  will 
have  to  be  obtained  by  the  use  of  more  power 
on  the  part  of  the  transmitting  stations. 

Second,  selectivity:  here  we  have  a  very 
much  more  definite  limit.  To  transmit  music 
of  high  quality  requires  not  a  single  frequency 
or  wavelength,  but  a  band  of  frequencies  about 
10,000  cycles  wide.  Thus,  a  station  that  ad- 
vertises a  concert  "on  600  meters"  will  really 
be  using  all  the  wavelengths  between  about 
594  and  606  metres,  while  a  station  transmitting 
on  300  metres  will  use  all  wavelengths  between 
298J  and  301^.  Hence  the  receiving  set  must 
receive  these  bands  of  wavelengths.  If  it  is  so 
selective  as  to  receive  only  a  narrower  band, 
the  quality  of  the  received  music  suffers.  On 
the  other  hand,  if  it  is  too  "  unselective"  to 
eliminate  signals  on  wavelengths  outside  of  the 
necessary  band,  then  there  is  just  so  much 
more  opportunity  for  interference  to  get  in. 
The  ideal  selectivity  would  be  realized,  of 
course,  only  when  all  wavelengths  lying  in  the 
necessary  band  are  received  equally  well  and 
wavelengths  outside  the  band  are  not  received 
at  all. 

Third,  ease  of  operation:  only  two  controls 
should  be  necessary,  one  to  select  the  station 
it  is  desired  to  hear,  and  the  other  to  regulate 
the  volume. 

The  super-heterodyne  system  can  be  made 
to  meet  all  these  requirements.  There  is  very 
little  trouble  in  getting  all  the  sensitivity  that  is 


desirable  for  working  with  a  loop  antenna.  The 
selectivity  can  easily  be  made  sufficiently  close 
to  the  ideal,  and  by  using  what  are  called  "  band 
pass  filters"1  it  could  be  made  ideal;  but  this 
refinement  hardly  seems  worth  while.  The 
controls  are  simple — one  knob  to  control 
volume  and  two  condensers  to  tune  with. 
Here  again,  the  ideal  could  be  attained  (if 
thought  worth  the  trouble)  by  gearing  or 
shafting  the  two  condensers  together  so  that 
turning  a  single  knob  would  operate  both 
condensers,  the  plates  being  cut  to  such  shape 
that  the  relative  values  of  the  capacities  would 
always  be  exactly  correct.  Or,  almost  as  good, 
a  single  knob  could  turn  two  ordinary  con- 
densers so  that  they  are  approximately  correct, 
and  a  small  vernier  condenser  in  parallel  with 
one  of  them  could  be  used  to  make  the  tuning 
exact  after  the  station  is  picked  up. 

Having  pointed  out  that  the  super-hetero- 
dyne method  meets  the  most  important  re- 
quirements of  a  radio  set  better  than  any  other 


'A  band-pass  filter  is  an  arrangement  of  capacities  and 
inductances  that  allows  almost  uniformly  free  passage  of  all 
frequencies  lying  in  a  specified  band,  but  almost  completely 
prevents  the  passage  of  currents  of  any  frequency  lying 
outside  this  band.  Band  pass  filters  can  be  made  success- 
fully to  pass  a  band  of  medium  frequencies, but  cannot  be 
made  to  pass  a  narrow  band  of  very  high  frequencies  such 
as  used  in  broadcasting.  Hence  they  could  not  be  em- 
ployed directly  in  an  ordinary  receiving  set,  but  if  the  super- 
heterodyne method  is  used,  the  intermediate-frequency 
amplification  can  be  made  to  take  place  at  a  frequency 
sufficiently  low  so  that  a  band  pass  filter  could  be  con- 
structed that  would  make  the  amplifier  satisfy  approxi- 
mately the  condition  previously  mentioned  for  ideal  selec- 
tivity. 


342 


Radio  Broadcast 


o 
o 


DL  35 


OL  50  TICKLER 


001  MFD. 


-1  1  I  I  I  I 


10  OR  12  VOLTS 


FIG.  I 

I  he  frequency  changer  is  used  to  alter  the  incoming  signals  so  that  they  may  be  put 
through  a  radio-frequency  amplifier  which  operates  on  comparatively  long  waves 


method  in  use  at  present,  it  will  be  well  to 
describe  this  method  briefly  before  going  on  to 
consider  the  actual  circuits.  The  funda- 
mental idea  is  supposed  to  have  resulted  from 
the  following  train  of  reasoning:  a  radio-fre- 
quency amplifier  is  comparatively  easy  to  build 
lor  long  wavelengths,  but  extremely  difficult 
to  make  operate  on  short  waves.  But  the 
signals  to  be  received  are  on  short  waves. 
Then  why  not  change  the  short-wave  signals 
into  long-wave  signals?  If  this  were  done, 
long-wave  radio  frequency  amplifiers  could  be 
used  to  receive  them.  Thus  a  super-heterodyne 
receiver  really  consists  of  two  units,  afrequency- 
changer  and  a  long-wave  receiving  set.  These 
two  units,  are  as  distinct  from  one  another  as  an 
ordinary  radio  set  and  the  audio-frequency 
amplifier  that  is  used  with  it.  If  you  have  a 
satisfactory  frequency-changing  unit,  you  can 
connect  it  up  to  any  kind  of  long-wave  amplifier 
and  detector,  or  vice  versa.  It  is  to  be  hoped 
that  in  the  future,  radio  apparatus  makers  will 
put  out  a  first  class  long-wave  amplifier-detec- 
tor unit  built  to  receive  a  fixed  band  of  fre- 
quencies about  10,000  cycles  wide.  The  ama- 
teur can  then  buy  one  of  these  and  make  his 
own  frequency-changer  to  feed  it,  just  as  he 
may  now  buy  a  Western  Electric  7A  audio 
amplifier  and  builds  his  own  radio  receiver  to 
feed  it. 

In  the  meantime,  the  amateur  will  have  to 
experiment  with  his  own  make  of  long-wave 
amplifier,  and  it  is  the  construction  of  this  that 
presents  the  only  difficult  problem  in  making  a 
super-heterodyne. 

Returning  to  the  frequency  changer,  its  oper- 


ation is  as  follows:  if  two  voltages  of  different 
frequencies  are  simultaneously  applied  to  the 
grid  of  a  detector  tube,  then  in  the  plate  circuit 
of  the  tube  will  be  found  a  number  of  currents 
of  different  frequencies,  among  these  being  a 
current  whose  frequency  is  equal  to  the  dif- 
ference between  the  two  frequencies  supplied 
to  the  grid.2  Our  frequency  changer,  then,  is  a 
detector  tube  having  two  frequencies  supplied 
to  it:  first,  the  signal,  which  is  picked  up  by  a 
loop  antenna,  and  second,  a  frequency  supplied 
by  a  separate  vacuum-tube  oscillator,  the 
"  heterodyne,"  which  feeds  the  detector  tube  by 
means  of  any  suitable  type  of  coupling.  I  n  the 
output  of  the  frequency  changer  there  will  then 
be  found  a  frequency  which  is  equal  to  the 
difference  between  the  signal  frequency  and  the 
frequency  of  the  heterodyne  oscillator,  By 
adjusting  the  heterodyne  frequency,  this  dif- 
ference may  be  made  anything  we  please.  The 
operation  may  be  illustrated  as  follows:  suppose 
we  have  a  long-wave  amplifier-detector  unit 
that  receives  only  waves  of  about  3,000  metres, 


2Assuming  that  the  plate-circuit  current  of  the  fre- 
quency-changer tube  varies  as  (K-f-grid  potential),2  where 
K  =  the"B"  battery  voltage  — the "C" battery  voltage  times 
the  amplification  constant  of  the  tube,  then  if  the  incoming 
radio  waves  produce  a  voltage  ls  sin  st  upon  the  grid  and  the 
heterodyne  oscillator  impresses  lh  sin  ht  upon  the  grid  at 
the  same  time,  the  plate  current  will  be  (k+ls  sin  st+li, 
sin  ht)2  =  k2-(-ls2  sin2  st+lh2sin2  ht+2klssin  st+2klh  sin  ht 
—  flhls  cos(s-r-h)t+JIslh  cos(s — h)t,  by  expanding  and  using 
a  simple  trigonometric  reduction.  It  is  the  last  term  only 
that  we  are  interested  in,  for  it  represents  the  current  having 
a  frequency  equal  to  the  difference  between  the  signal  and 
heterodyne  frequencies.  The  coefficient  I  ls  lh  shows  that 
the  strength  of  this  current  is  directly  proportional  to  the 
strength  of  the  voltage  introduced  by  the  heterodyne  oscil- 
lator, hence  the  advantage  of  making  this  as  great  as  pos- 
sible. 


A  Practical  Super-Heterodyne  with  199's 


343 


which  is  a  frequency  of  100  kilocycles.  Now 
suppose  a  signal  is  coming  in  at  a  wavelength 
of  400  metres,  which  is  a  frequency'  of  750 
kilocycles.  If  we  adjust  the  heterodyne  tube 
to  oscillate  at  a  frequency  of  850  kilocycles, 
then  the  difference  between  the  heterodyne 
frequency  and  the  signal  frequency  is  100 
kilocycles,  and  this  is  just  right  to  be  fed  to 
the  long-wave  amplifier.  On  the  other  hand, 
if  the  heterodyne  oscillated  at  650  cycles,  the 
difference  would  again  be  100  kilocycles. 
Thus  there  are  always  two  possible  settings  for 
the  condenser  that  adjusts  the  frequency  of  the 
heterodyne  oscillator,  either  of  which  will  bring 
in  the  same  station.  Sometimes  it  will  be 
found  better  to  use  one  than  the  other,  but 
usually  it  makes  no  difference. 

In  building  a  frequency-changing  unit,  the 
chief  points  are:  use  as  high  a"  B"  battery  voltage 
as  available  on  both  the  frequency  changing 
tube  and  the  heterodyne;  in  the  grid  circuit  of 
the  heterodyne  oscillator  put  a  grid  condenser 
and  leak  that  will  allow  the  tube  to  oscillate 
most  strongly  (say  .002  mfd.  or  more  and  5000- 
ohm  leak);  in  the  grid  circuit  of  the  frequency- 
changingtubeputanamount  of  "C"  battery  that 
can  best  be  determined  by  experiment  (if  90 
voltsof  "B"  battery  are  used,  10  or  i2voltsof  "C" 
battery  will  be  about  right) ;  and,  finally,  adjust 
the  coupling  between  the  heterodyne  oscillator 
and  the  frequency-changing  tube  so  as  to  get 
plenty  of  the  heterodyne  frequency  supplied 
to  the  frequency-changing  tube.  Up  to  a  cer- 
tain point,  the  more  the  better,  because  the 
output  of  the  frequency-changer  tube  is  pro- 
portional to  the  product  of  the  signal  and  the 
heterodyne  voltages. 

Any  sort  of  heterodyne  oscillator  circuit  can 


be  used,  and  coupled,  in  any  fashion.  One  con- 
venient arrangement  is  the  use  of  a  three-coil 
honeycomb  mounting  which  allows  trying  dif- 
ferent coils  and  a  great  range  of  wavelengths  to 
be  received.  These  three  coils  are  connected 
as  shown  in  the  circuit  diagram,  Fig.  1.  The 
D.  L.  35  and  the  tickler  coils  should  be  the 
movable  ones. 

As  the  only  two  adjustments  in  tuning  are 
the  two  variable  condensers  here  shown,  it  is 
well  worth  while  to  get  the  very  best  con- 
densers for  the  purpose.  The  receiver  tunes 
very  sharply,  and  a  list  of  stations  with  the 
exact  settings  of  the  condensers  cannot  be  kept 
unless  the  construction  is  so  rigid  that  a  certain 
setting  always  gives  the  same  capacity.  For 
this  reason  it  is  inconvenient  to  use  condensers 
with  separate  verniers.  The  General  Radio 
condenser,  with  a  small  knob  turning  the  con- 
denser through  a  reduction  gear,  is  completely 
satisfactory. 

There  should  be  no  difficulty  in  building  a 
good  frequency-changing  unit,  and  once  made, 
it  can  be  used  without  change  in  connection 
with  any  new  or  improved  long-wave  amplifier 
that  may  later  be  put  on  the  market  or  de- 
scribed. The  scheme,  mentioned  earlier  in  this 
article,  of  gearing  the  two  condensers  together 
so  as  to  have  only  one  knob  to  turn,  is  not  rec- 
ommended to  the  average  constructor.  Na- 
ture has  given  us  two  hands,  and  after  a  little 
practice  it  is  not  difficult  to  turn  the  two  con- 
densers simultaneously,  keeping  their  relative 
values  about  right. 

We  now  come  to  the  more  difficult  unit  to 
build,  the  long-wave  amplifier.  Before  taking 
up  the  question  of  the  best  type,  a  very  easy 
type  to  make  will  be  described.    The  reason  it 


The  intermediate-frequency  amplifier  is  coupled  to  the 


condensers. 


60  V. 


•1G.  2 

frequency  changer  by  two  DL750  coils  shunted  by  .001  variable 


The  amplifier  itself  is  made  with  UV-.1716  transformers  and  each  stage  is  thoroughly  shielded  as  shown  by 

the  dotted  lines 


344 


Radio  Broadcast 


REAR  VIEW  OF  THE  EXPERIMENTAL  SUPER-HETERODYNE  SET 
The  covers  that  complete  the  shielding  are  removed.    At  the  extreme  left  is  the  inductance  coil  for  the  tuned  shunt 
that  by-passes  the  intermediate-frequency  current  around  the  phones.    This  set  runs  on  four  new  dry  cells  and  60  volts 
B  battery,  and  operates  a  10-D  loud  speaker  very  nicely  for  powerful  stations  up  to  about  fifty  miles  away 


is  easy  is  because  the  transformers  used  are  the 
Radio  Corporation  long-wave  transformers  and 
do  not  require  tuning.  The  only  precaution  is 
to  put  some  shielding  between  stages,  prefer- 
ably having  each  stage  in  a  metal  compartment 
(which  however  needs  no  top  on  it).  In  the 
circuit  diagram,  Fig.  2,  the  metal  is  indicated 
by  the  dotted  lines  and  it  will  be  noticed  that 
the  grid  lead  to  each  tube  is  as  short  as  possible. 

The  loose  coupling .  between  the  D.  L.  750 
coils  gives  the  selectivity.  Once  the  best 
tuning  and  coupling  are  found,  this  is  never 
changed.  The  variable  condenser  and  in- 
ductance in  the  compartment  with  the  detector 
tube  play  a  very  important  part  in  preventing 
the  amplifier  from  howling.  In  most  receiving 
sets  there  is  a  "by-pass"  condenser  to  shunt 
the  radio-frequency  currents  around  the 
phones,  but  unless  this  capacity  is  very  large, 
only  a  portion  of  the  current  is  shunted.  In 
the  case  of  an  amplifier  working  on  a  fixed  fre- 
quency, however,  this  shunt  circuit  can  be 
tuned  so  as  to  by-pass  all  the  radio  frequency, 
so  that  none  of  it  gets  outside  the  metal  com- 
partment and  thus  cannot  get  back  to  the  input 
of  the  amplifier  and  cause  howling.  This  de- 
vice is  especially  necessary  if  any  reflexing  is  to 
be  done.  An  .001  "Variadon"  condenser  and 
a  D.  L.  750  coil  will  obviously  tune  to  the  right 
frequency,  for  this  is  the  combination  used  to 
tune  the  input  to  the  amplifier,  but  it  would  be 
better  to  use  the  smallest  coil  that  can  be  tuned 
by  the  .001  condenser  to  the  frequency  used. 

If  the  amplifier  still  howls  in  spite  of  this 


tuned  shunt,  try  reversing  the  connections  to 
the  primary  of  one  of  the  radio-frequency 
transformers.  Also  try  tuning  the  "Variodons" 
in  the  input  to  various  frequencies.  A  setting 
can  usually  be  found  where  the  oscillations  of 
the  amplifier  will  stop.  If  not,  something  is 
wrong  with  the  wiring,  or  a  bad  "B"  battery  is 
being  used,  or  the  leads  to  the  "B"  battery  are 
too  long. 

RESULTS  WITH  20I-A's 

USING  a  frequency  changer  and  long-wave 
receiver  having  the  constants  shown,  and 
one  stage  of  audio  amplification  with  6  volts 
of  "C"  battery  on  the  grid  of  the  audio  amplifier 
tube  and  90  on  the  plate,  all  six  tubes  being 
UV-201-A's,  very  good  loud  speaker  results 
were  obtained.  Stations  up  to  100  miles  away 
were  received  loudly  enough  in  day  time  to  be 
heard  all  over  a  fair-sized  room,  using  a  Western 
Electric  10-D  loud  speaker.  At  night  the  sensi- 
tivity was  good  enough  to  allow  stations  as  far 
west  as  KHJ  and  KFI  in  California  to  be  heard 
on  the  loud  speaker  (from  Princeton,  N.  J.), and 
others  not  so  far  but  of  lower  power  and  hence 
even  more  difficult  to  pick  up.  As  a  result  of  the 
work  with  this  amplifier,  it  was  concluded  that 
with  UV-201-A  tubes,  if  everything  is  made  to 
work  its  best,  two  stages  of  intermediate-fre- 
quency amplification  is  all  there  is  any  practical 
use  for.  Another  stage  could,  of  course,  have 
been  put  in  and  the  amplification  cut  down  to 
the  desired  amount  by  a  device  such  as  will  be 
described  later. 


A  Practical  Super-Heterodyne  with  199's 


345 


THE  UV-I99  TUBE 

THE  receiver  just  described  is  well  within 
the  ability  of  the  average  constructor  to 
duplicate  and  perhaps  improve  upon.  More 
experienced  radio  fans  may,  however,  like  to 
tackle  the  proposition  of  making  a  set  to  run  on 
dry  cells.  Assuming  that  six  Radiotron  UV- 
199's  are  used,  they  can  be  arranged  in  three 
groups,  each  group  having  the  filaments  in 
series.  Thus  only  180  milliamperes  will  be  re- 
quired and  can  be  supplied  by  5  dry  cells  in 
series,  with  a  10-ohm  rheostat  that  can  be  cut 
out  as  the  dry  cells  run  down.  The  heterodyne 
tube  and  the  frequency-changing  tube  can  have 
their  filaments  in  series,  and  the  final  detector 
and  the  first  intermediate-frequency  tube  are 
also  in  series.  Three  stages  of  radio-frequency 
amplification  are  required  because  the  output  of 
the  frequency  changer  as  well  as  the  amplifica- 
tion per  stage  will  be  less  when  using  199's 
than  with  201-A's.  To  get  the  most  out  of  the 
tubes,  a  stage  of  audio  can  be  added  by  reflexing 
back  to  one  of  the  radio-frequency  amplifier 
tubes.  To  get  the  most  out  of  each  stage  of 
radio-frequency  amplifier  tubes,  transformers 
should  be  used  that  match  the  impedance  of 
the  199  tube,  and  at  the  same  time  supply  the 
necessary  selectivity.  Four  tuned  transformers 
will  give  too  great  an  overall  selectivity  for 
good  quality  if  very  long  waves  are  used,  so 
that  it  is  better  to  use  a  fairly  high  intermediate 
frequency,  and  this  in  turn  will  probably  render 
necessary  the  use  of  the  "neutrodyne"  system 
for  the  prevention  of  regeneration  due  to  the 
internal  capacity  of  the  tubes.  This  is  in  addi- 
tion to  shielding  each  stage  as  well  as  possible 
by  putting  each  in  a  separate  metal  compart- 


ment. Finally,  the  loudness  of  the  signals  can 
be  controlled  by  a  rheostat  of  about  50  ohms  in 
series  with  the  filaments  of  either  pair  of  tubes 
in  the  intermediate-frequency  unit.  If  the 
audio  current  is  reflexed  back  to  the  first  tube 
in  this  unit,  then  the  above  mentioned  rheostat 
should  control  the  filament  currents  in  the 
second  and  third  tubes,  while  if  the  audio  is 
reflexed  back  through  the  second  or  third  tubes, 
the  rheostat  should  control  the  filament  current 
through  the  first  tube  and  detector.  Th,us  the 
tube  doing  the  audio-frequency  amplifying  will 
always  have  its  filament  current  up  to  normal, 
and  the  quality  will  not  be  affected  by  cutting 
in  the  control  resistance.  The  advantage  of 
reflexing  back  to  the  first  tube  is  that  it  is  the 
one  least  "loaded"  by  the  high  frequency, 
while  the  disadvantage  is  that  any  feed-back 
is  more  likely  to  make  the  amplifier  regenerate 
or  oscillate.  It  is  of  course  possible  to  obtain 
two  stages  of  audio  amplification  by  the  "  in- 
verse duplex"  arrangement,  but  even  if  the  dif- 
ficulty of  keeping  the  amplifier  stable  is  over- 
come, the  quality  is  likely  to  suffer,  and  one 
stage  is  sufficient  when  working  with  the  head 
set. 

A  receiver  built  upon  the  foregoing  plan  (see 
Fig.  3  and  photos)  was  built  by  the  author  at 
Princeton  and  has  been  used  for  a  week  or  so 
with  very  good  results.  Although  June  is  not 
a  very  good  month  for  long-distance  work, 
Chicago  stations  are  heard  regularly  at  night, 
and  several  other  fairly  distant  ones  have  been 
heard,  notably  6KW  in  Cuba,  a  low-powered 
set.  The  operation  of  the  set  is  a  pleasure. 
The  two  condensers  have  to  be  set  just  right, 
and  if  both  of  them  are  moved  even  a  degree 
or  so,  loud  local  stations  drop  out  of  hearing 


fig.  3 


1  ivj-  0 

The  circuit  diagram  for  the  complete  receiver  built  and  used  by  Mr.  Roberts,  a  and  b=DL50  coils;  c=DL^^;  d  =  -jo- 
turn  coil  of  32D.C.C.  wire  on  the  tube  inside  e;  e  =  DL250;  F  =  Variodons;  G  =  audio  transformer;  H  =  closed-circuit  jack; 

1  =  open-circuit  jack;  J  =  DL200 


346 


Radio  Broadcast 


completely.  The  amplifier  is  very  stable, 
whether  one  is  listening  in  on  the  detector  or 
with  the  stage  of  audio  amplification,  and  the 
8o-ohm  rheostat  controls  the  volume  perfectly. 
However,  the  sensitivity  can  probably  be  much 
improved  by  perfecting  the  design  of  the  R.  F. 
transformers.  The  ones  in  use  at  present 
have  a  secondary  consisting  of  a  250  D.  L. 
coil  tuned  by  an  .0004  Variadon.  The  primary 
is  about  70  turns  of  32  D.  C.  C.  wire  wound 
on  a  cardboard  mailing  tube  of  such  size  that 
the  primary  fits  snugLy  inside  the  D.  L.  250  coil. 
The  connections  are  such  that  current  entering 
the  primary  from  the  plate  circulates  in  a 
direction  opposite  to  that  of  current  entering 
the  secondary  from  the  grid.  This  is  necessary 
to  "  neutrodyne."  This  design  was  the  only 
one  tried,  and  probably  can  be  considerably 
improved.  In  putting  the  set  in  operation,  the 
steps  are  as  follows:  start  with  all  the  neutro- 
dyning  capacities  obviously  too  great — using, 
say,  pennies  about  j  inch  apart.  Set  all  the 
secondary  condensers  to  the  same  values. 
Listen  in  on  the  detector  and  pick  up  some 
loud  local  station.  Then  leaving  the  two 
condensers  in  the  frequency  changer,  alone, 
go  over  all  the  condensers  in  the  intermediate- 
frequency  amplifier  and  get  the  best  setting 
for   each.    Then    reduce   the  neutrodyning 


capacities  to  a  point  just  above  regeneration 
(with  199  tubes  no  neutrodyne  capacity  at 
all  is  absolutely  necessary  for  the  lower 
frequencies).  Finally,  plug  into  the  audio- 
amplifier  output  and  adjust  the  tuning  of  the 
shunt  between  the  detector  plate  and  filament 
so  that  there  is  no  tendency  for  the  set  to 
oscillate.  The  set  should  now  be  working 
satisfactorily.  After  using  it  a  few  days  so  as 
to  know  about  how  sensitive  it  is,  try  using  a 
different  intermediate  frequency  by  changing 
all  the  condensers  across  the  transformer 
secondaries  in  that  circuit  and  going  through 
the  same  process.  In  this  fashion  the  best 
frequency  to  work  at  will  be  found.  There  will 
probably  not  be  a  great  deal  of  difference. 

The  foregoing  hints  have  been  given  in  a 
rather  sketchy  fashion  because  it  is  assumed 
that  any  one  competent  to  improve  upon  the 
transformers  will  not  require  a  more  detailed 
description.  After  further  experiments  which 
he  intends  to  make,  if  the  writer  hits  upon  a 
transformer  design  that  completely  satisfies 
him,  an  exact  description  of  it  will  be  given;  so 
that  any  one  with  good  mechanical  ability  will 
be  able  to  build  himself  this  six-tube  dry-cell 
receiver  that  has  all  the  advantages  of  the  super- 
heterodyne control,  the  neutrodyne  type  ampli- 
fier, and  the  "reflex"  system,  rolled  into  one. 


A  New  Regenerative  Radio- 
Frequency  Combination 


By  ROGER  A.  WEAVER 


WHILE  experimenting  with 
regenerative  receivers  for 
operation  on  ground  circuits, 
a  broadcast  fan  developed  a 
circuit  with  remarkable 
possibilities.  One  of  the  original  models  of 
the  apparatus  was  made  in  the  office  of  the 
editor  of  Radio  Broadcast,  and  in  initial  tests, 
signals  were  received  from  Calgary,  Alberta, 
without  any  antenna  and  using  a  steam  pipe 
ground  system  for  intercepting  the  ether  waves. 

During  the  remainder  of  the  summer,  Mr. 
Wagner  and  Mr.  Lynch  carried  on  extensive  ex- 
perimental work,  constructing  various  models 
of  receivers.  In  the  fall  of  1922,  Mr.  A.  H. 
Grebe  became  interested  in  these  experiments, 


and  shortly  after  that  time  Mr.  Wagner  joined 
the  engineering  staff  of  A.  H.  Grebe  &  Co., 
Inc.,  for  the  purpose  of  developing  the  new 
receiver. 

After  some  months  of  experimenting,  a  re- 
ceiver was  built  fulfilling  every  requirement 
for  long  range,  adaptability,  and  simplicity 
of  operation. 

As  may  be  seen  from  the  accompanying  il- 
lustrations, the  receiver  is  entirely  self- 
contained,  except  for  the  loud  speaker,  and  a 
20-ft  length  of  silk-covered  wire  which  is  used 
for  the  aerial.  This  wire  may  be  concealed 
beneath  the  carpet  or  run  along  the  picture 
molding.  There  are  separate  rheostat  controls 
for  each  tube,  and  switches  are  provided  for 


RADIO  BROADCAST  ADVERTISER 


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contains  a  list  of  the  leading  broadcasting 
stations  in  the  United  States  and  Canada, 
several  efficient  hook-ups,  and  an  explana- 
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This  booklet  will  be  sent  free  on  request. 
Just  drop  us  a  line. 


Tested  and  approved  by  Radio  Broadcast  -fa 


348 


Radio  Broadcast 


changing  the  rheostat  range  from  either  0-5  or 
0-50  ohms.  This  permits  the  use  of  any  desired 
combination  of  tubes,  from  UV-199,  which  con- 
sumes but  60  milliamperes  to  the  201's  which 
may  draw  as  high  as  one  ampere.  Of  course, 
it  is  expected  that  the  receiver  will  be  used  with 
dry-battery  tubes,  and  compartments  have 
been  provided  for  both  filament  and  plate 
batteries. 

An  operating  switch  located  on  the  lower 
right  corner  of  the  panel  controls  the  filament 
and  output  circuits  in  such  a  manner  that  when 
this  switch  is  pulled  all  the  way  out,  all  four 
tubes  are  lighted,  and  when  the  switch  is  pulled 
but  half  way  out  only  three  tubes  are  lighted. 
With  the  switch  in  the  latter  condition,  the 
set  may  be  used  with  head  telephones  for  dis- 


tant reception,  or  with  a  loud  speaker  for  local 
reception.  An  "Aerial  Switch,"  located  at  the 
extreme  left  of  the  panel,  controls  a  set  of  small 
mica  condensers  which  are  necessary  to  provide 
for  the  variation  in  wavelength  range  incident 
to  the  use  of  the  set  in  various  locations.  Un- 
der all  circumstances,  it  is  possible  by  means  of 
this  switch  to  tune  in  the  complete  wavelength 
range  of  200  to  600  meters.  For  the  direct 
control  of  wavelength,  two  dials  with  the  usual 
Grebe  tangent  wheel  verniers  are  used.  One 
of  these,  the  "Secondary  Wavelength  Dial," 
is  calibrated  directly  in  wavelengths,  thus 
facilitating  speed  and  accuracy  in  tuning  to 
distant  stations  of  known  wavelength  but  low 
audibility.  Tuning  of  the  primary  circuit  is  ac- 
complished with  a  similar  dial,  while  the , control 
of  regeneration  is  effected  through 
the  movement  of  the  small  tan- 
gent wheel  centrally  located  be- 
tween the  wavelength  dials. 

A  feature  well  worthy  of  men- 
tion is  the  manner  in  which  two 
or  more  of  these  receivers  oper- 
ate in  close  proximity  of  one 
another.  Three  of  these  receiv- 
ers were  installed  in  one  room, 
and  operated  simultaneously 
without  any  material  effect  of 
r.eradiation  being  noticeable. 
For  example,  it  was  possible  to 
tune  in  one  set  to  WEAF,  and 
then  proceed  to  tune  the  second 
and  third  sets  to  the  same  wave- 
length without  causing  a  disturb- 
ance, 


RADIO  BROADCAST  ADVERTISER 


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The  Grid 


QUESTIONS  AND  ANSWERS 

The  Grid  is  a  Question  and  Answer  Department,maintained  especially  for  the  radio  amateurs.  Full 
answers  will  be  given  wherever  possible.  In  answering  questions  ,  those  of  a  like  nature  will  be  grouped 
together  and  answered  by  one  article.  Every  effort  will  be  made  to  keep  the  answers  simple  and  direct, 
yet  fully  self-explanatory.  Questions  should  be  addressed  to  Editor,  "  The  Grid,"  Radio  Broadcast, 
Garden  City,  N.  Y. 


Summer   Receiving  Conditions   and  the   Ideal  Set 

During  the  last  two  months  my  receiving  set  has  become 
comparatively  inoperative.  During  the  winter  I  was  able 
to  hear  stations  as  far  west  as  Davenport,  Iowa.  I  also 
heard  Havana-  on  several  occasions,  many  stations  in  the 
southern  states,  to  say  nothing  of  several  Canadian  broadcas- 
ters. Now  I  am  able  to  receive  nothing  farther  away  than  five 
hundred  miles,  and  most  of  my  evenings  are  spent  listening 
to  WGY,  WEAF,  IVOR,  KDKA  and  WJZ,  all  compara- 
tively near,  and  who  {especially  WGY  and  KDKA)  do  not 
come  in  with  anything  like  their  former  loudness.  My  set  has 
not  been  changed  in  over  eight  months,  excepting  batteries,  and, 
thinking  that  the  fault  might  be  in  the  antenna,  I  recently 
erected  a  new  one  without  improving  matters. 

My  set  has  also  developed  a  crackling  which  even  the  most 
careful  investigation  of  connections  and  batteries  has  been  un- 
able to  eliminate  in  the  slightest  degree. 

Can  you  give  me  any  idea  as  to  what  is  wrong  with  my 
apparatus? 

R.  L.  S.,  Nutlf.y,  N.  J. 

THAT  the  thousands  who  have  become  broadcast 
enthusiasts  during  the  past  winter  have  yet  to  learn 
the  radio  significance  of  summer,  is  evident  from  many 
letters  similar  to  the  above  which  have  recently  been  ad- 
dressed to  this  department.  The  plaint  of  our  correspon- 
dent is  as  old  as  the  wireless  game  itself,  and  it  emphasizes  a 
field  of  radio  endeavor  that  has  yet  to  capitulate  to  science. 

Reception  drops  off,  to  a  very  appreciable  extent,  in  the 
warm  months,  and  it  is  often  less  than  fifty  per  cent,  as 
efficient  as  during  the  cold,  clear  winter  nights.  The  crack- 
ling noise  of  which  the  writer  speaks  is  "static,"  without 
a  doubt.    The  sound  will  probably  cease  with  the  discon- 


nection of  the  antenna,  proving  that  it  is  due  to  "X's" 
or  "strays"  which  the  radio  world  for  twenty  years  has 
sought  to  eliminate. 

Unless  the  enthusiast  is  willing  to  alter  his  apparatus 
so  as  to  conform  with  the  requirements  of  summer  recep- 
tion, he  must  bow  to  these  conditions  as  inevitable.  How- 
ever, the  addition  of  radio-frequency  amplification  to  ap- 
paratus operating  from  an  open  antenna  will  bring  back 
the  distance  reception  which  was  possible  on  fewer  tubes 
during  the  winter.  Two  stages,  or  at  the  most,  three,  of 
transformer-coupled  R.F.,  or  sometimes  a  single  stage  of  a 
correctly  installed  and  operated  tuned-plate  amplifier,  will 
suffice  to  accomplish  this.  Radio-frequency  amplification 
will  also,  to  an  extent,  reduce  the  effect  of  static,  and  in  no 
case  will  the  static  be  appreciably  amplified.  This  is  due  to 
the  limiting  effect  of  R.  F.,  as  well  as  to  its  discrimination 
against  all  frequencies  other  than  that  to  which  the  ampli- 
fier is  tuned.  Static  disturbances,  incidentally,  are  much 
more  noticeable  and  prevalent  on  the  higher  waves. 

Static  can  be  practically  eliminated  by  receiving  on  loop, 
using  the  requisite  R.  F.  amplification,  reception  often  be- 
ing possible  in  the  midst  of  a  thunder  storm.  Ambitious 
experimenters  will  do  well  to  arrange  an  R.  F.  set  that  may 
be  thrown  from  open  aerial  to  loop  antenna,  thus  insuring 
fairly  consistent  reception  throughout  the  summer,  re- 
gardless of  atmospheric  conditions.  Such  a  circuit,  with 
the  suggested  switching  arrangement,  is  shown  in  Fig.  I. 
The  construction  of  a  suitable  loop  antenna  was  described 
in  the  June,  1923,  grid. 

Interference  and  Fading  Caused  by  a  Near-by  Set 

/  have  a  two-stage  regenerative  set  which  is  the  same,  as 
owned  by  my  next  door  neighbors.    IV hen  I  am  tuned  in  on  a 


FIG,  I 


RADIO  BROADCAST  ADVERTISER 


Out  of  Door's  with  a 

Portable  Radiola 


RADIOLA  II 

Take  it  along — up  to  the  moun- 
tains— out  to  the  beach.  On 
every  auto  trip  and  every  camp- 
ing trip. 

Throw  an  insulated  wire  over  a 
tree.  That's  all  the  antenna 
you  need.  Attach  a  ground 
wire  to  a  bit  of  pipe  in  the 
earth,  or  a  house  pipe  indoors. 
That's  all  the  installation  you 
need. 

When  it's  home,  the  portable 
Radiola  is  a  fine  piece  of  furni- 
ture, of  rich  mahogany  finish. 
When  it's  out-o'-doors,  it's  an 
easy-to-carry  set,  with  a  handle 
to  carry  it  by,  and  all  its  bat- 
teries tucked  away  inside  it. 
Two  tubes  give  it  power  to  hear 
over  long  distances — or  to  oper- 
ate on  a  loud  speaker  over  short 
distances. 

This  symbol  of  quality  is  your  protection 


" 'There  s  a  Radiola  Jor  every  purse" 

At  the  nearest  Radio  or  Electrical  Store 

Radio  Corporation  of  America 


* 


Sales  Department 
233  Broadway,  New  York 
District  Sales  Offices 
10  So.  LaSalle  St.,  Chicago,  111. 
433  California  St. , San  Francisco,  Cal, 


RADIOLA  II 

with  two  Radio- 
trons  UV-199, 
all  batteries  and 
pair  of  h 
phones:  $97 


Radiola 


.  Radio  Corporation  of  America 
I        Dept.  2066  (address  nearest  office  listed) 

I  Please  send  me  your  free  Radio  Booklet  describing 

|  sets  from  $25  to  $350. 

I  Name  


REG.  U.  S.  PAT.  OFF. 


I  Street  Address_ 

|  City  

I  State  


R.F.D._ 


■fa  Tested  and  approved  by  Radio  Broadcast  -jf 


Radio  Broadcast 


station  and  they  tunc  in,  it  causes  a  lot  of  noise  and  lessens 
the  strength  of  my  signals.  Ow  aerials  are  about  twenty 
feet  apart.  Theirs  is  a  two-wire  antennfi,  125  feet  long, 
while  mine  is  a  single- sir  and,  160  feel  long,  strung  about 
five  feet  lower  than  theirs. 

Is  there  any  way  of  overcoming  this  interference! 

K.  B.  Wilkes-Barre,  Pa. 

JUDGING  from  the  results,  the  probability  is  that  the 
two  stations  in  question  are  using  single-circuit  regen- 
erative sets,  and  the  above  is  a  fair  example  of  the  dif- 
ficulties to  which  the  too  general  adoption  of  apparatus 
of  this  type  has  given  rise.  Though  the  antennas  in  this 
case  are  unusually  close  together,  the  same  condition  is 
found  in  many  congested  radio  districts. 


The  noise  is  doubtless  a  heterodyne  caused  by  the  inter- 
action of  the  individual  oscillations  set  up  in  each  antenna 
during  the  process  of  tuning,  or  the  conjunction  of  one  or 
both  with  the  broadcasting  wave. 

The  undesirable  effects  can  doubtless  be  greatly  reduced 
by  running  the  two  aerials  at  right  angles  to  each  other. 
However,  as  it  is  almost  impossible  to  tune  a  single-circuit 
receiver  without  throwing  it  into  an  oscillating  state,  the 
disturbances  can  be  totally  eliminated  only  by  a  complete 
change  in  equipment  at  both  stations.  Radio  Broadcast 
recommends  a  receiver  of  the  primary,  secondary,  and 
tickler  type  operated  with  loose  coupling,  or  a  variocoupler 
and  twin-variometer  regenerator.  These  receivers  radiate 
comparatively  weak  oscillations,  and  are  more  selective 
than  the  single-circuit  sets. 


Supplemental  List  of  Broadcasting  Stations  in  the  United  States 

LICENSED  FROM  MAY  18  TO  JUNE  15  INCLUSIVE 


CALL 
SIGNAL 

KFHP 

KFHQ 

KFHS 

KFIJ 

KFIK 

KFIL 

KFIO 

KFJA 

KFJB 

KFJD 

KFKA 

KFKH 

KFLE 

WABI 

WABJ 

WABK 

WABL 

WABM 

W  ABN 

WABO 

WCBA 

WBBD 

WCBD 

WDBC 

WDBF 

WJY 

WJZ 

WRAW 

WRAX 

WSAD 

WTAG 

WTAK 


Radio-Bug  Products  Co.,  Kearney,  Nebr  

Curtis  Bros.  Hardware  Store,  Los  Gatos,  Calif.  . 

Dow,  Clifford  J.,  Lihue,  Hawaii  

Sidney  I.  Thorean,  Platte,  S.  Dak  

Gladbrook  Electrical  Co.,  Gladbrook,  Iowa  . 
Windisch  Elect.  Farm  Equipt.  Co.,  Louisburg,  Kansas 
North  Central  High  School,  Spokane,  Wash. 

Central  Power  Co.,  Grand  Island,  Neb  

Marshall  Elect.  Co.,  Marshalltown,  Iowa      .     .     .  . 
Weld  County  Printing  &  Publishing  Co.,  Greeley,  Colo. 
Colorado  State  Teachers  College,  Greeley,  Colo. 
Denver  Park  &  Amusement  Co.,  Lakeside,  Colo. 
National  Educational  Service,  Denver,  Colo. 

Bangor  Railway  &  Electric  Co.,  Bangor  Me  

The  Radio  Laboratories,  South  Bend,  Ind  

First  Baptist  Church,  Worcester,  Mass  

Connecticut  Agri.  College,  Storrs,  Conn  

Doherty,  F.  E.,  Saginaw,  Mich  

Grover,  Waldo  C,  La  Crosse,  Wis  

Lake  Avenue  Baptist  Church,  Rochester,  N.  Y.. 
Charles  W.  Heimbach,  Allentown,  Pa.     .  . 

Barbey  Battery  Service,  Reading,  Pa  

Voliva,  Wilber  Glenn,  Zion,  111  

Kirk  Johnson  &  Co.,  Inc.,  Lancaster,  Pa.   

Phillips,  Robert  G.,  Youngstown,  Ohio  

Radio  Corporation  of  America,  New  York,  N.  Y.  . 
Radio  Corporation  of  America,  New  York,  N.  Y.  . 

Good,  Horace  D.,  Reading,  Pa.     .  .  

Flexon's  Garage,  Gloucester  City,  N.  J  

J.  A.  Foster  Co.,  Providence,  R.  I  

Kern  Music  Co.,  Providence,  R.  I.  

Swan-Bower  Co.,  The,  Steubenville,  Ohio  


FREQUENCY 

WAVE- 

(Kilocycles) 

LENGTH 

1 220 

246 

1240 

242 

1090 

275 

1270 

236 

1280 

234 

1280 

234 

1 190 

252 

1230 

244 

1210 

248 

1270 

236 

1210 

248 

1330 

226 

1 120 

268 

1250 

240 

1250 

24O 

1 190 

252 

1060 

283 

1 180 

254 

1280 

234 

1 190 

252 

1070 

280 

1280 

234 

870 

345 

1 160 

258 

1 1 50 

261 

740 

405 

660 

455 

1260 

238 

1 120 

268 

1 1  50 

261 

1 160 

258 

1 130 

266 

DELETIONS  FROM  MAY  1  TO  MAY  30 


KDN    San  Francisco,  Calif. 

KDZH    Fresno,  Calif. 

KFAZ    Reedley,  Calif. 

KFCQ  ......  Casper,  Wyo. 

KFGF    Mount  Vernon,  Wash. 

KFGM    Abilene,  Tex. 

KFHC    Norman,  Okla. 

KFV    Yakima,  Wash. 

KLB    Pasadena,  Calif. 

KQY    Portland,  Oreg. 

KYI    Bakersfield,  Calif. 

KYJ    Los  Angeles,  Calif. 

WAAJ    Boston,  Mass. 


WAAQ    Greenwich,  Conn. 

WAAS    Decatur,  Ga. 

WD  AC    Springfield,  III. 

WEAT    Tampa,  Fla. 

WFAU    Boston,  Mass. 

WGAD    Ensenada,  P.  R. 

WGAH  ......  New  Haven,  Conn. 

WGAJ    Shenandoah,  Iowa 

WHAR    Atlantic  City,  N.  J. 

WJZ    Newark,  N.  J.  . 

WPA    Fort  Worth,  Tex. 

WPM    Washington,  D.  C. 

WWAJ    Columbus,  Ohio. 


10,000  Miles  of  Radio  Lectures  in  China 


Prize- Winning  Hookups 
■  I  Set- Backs  and  Come- Backs  at  6KW 


How  Vacuum  Tubes  are  Made 


[r 


A  Specially 
Designed  Tube 
For  Every 
Radio  Use 


The  Ideal  Tube 
For  the  Call  of  the  Open 

Are  you  spending  your  vacation  in  the  North 
Woods — at  the  seashore — in  one  of  our  many 
great  national  parks,  or  are  you  motoring  across 
country?  In  any  event  the  new  Cunningham 
dry  battery  detector  and  amplifier,  type  C-299, 
makes  it  possible  for  you  to  take  a  radio  receiver, 
which  will  be  light  in  weight,  compact  in  design, 
and  highly  efficient  in  operation.  It  is  the  special 
filament  in  this  tube,  having  a  current  so  low 
that  it  may  receive  its  supply  from  standard 
No.  6  dry  batteries  or  even  from  ordinary  flash- 
light batteries,  that  makes  possible  this  new  and 
interesting  application  of  radio. 

The  receiving  set  you  now  have  can  be  readily 
adjusted  to  use  this  new  tube  and  be  a  source 
of  use  and  pleasure  on  your  vacation  trip.  In 
any  event  your  dealer  can  give  you  useful  sug- 
gestions for  the  purchase  or  construction  of  a 
highly  efficient  and  practical  portable  set. 

D_j._„4.  ]VT  —  4. 1 —  .  Cunningham  tubes  are  cov- 
ratent  INOtlCe:  ered  by  patents  dated  11-7- 
05,  1-15-07,  2-18-08,  and  others  issued  and  pending. 
Licensed  for  amateur,  experimental  and  entertainment 
use  in  radio  communication.  Any  other  use  will  be 
an  infringement. 


Home  Office: 
248  First  Street 
San  Francisco,  Calif. 


Eastern  Representative: 
Chicago,  Illinois 


^  Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


A  four  lube  set  in  a  beautiful,  upright,  mahogany  fin- 
ished cabinet.  The  hinged  lid  and  doors  give  easy  access  to 
any  part  of  the  receiving  apparatus.  The  lower  compart- 
ment is  for  batteries. 


Model  VI— Price  S28.00 


This  Model  contains  the  stage  of  tuned  radio  frequency 
amplification  brought  to  100%  perfection  by  the  Crosley  Co. 
For  its  price  and  size,  it  gives  surprising  results  in  long  range 
reception.  Hundreds  of  testimonials  have  paid  tribute  to  its 
efficiency. 


Crosley 
Type  "D"  Condenser — $2.25 

The  wonderful  efficiency  of  this 
new  condenser  has  caused  its  popu- 
larity to  grow  rapidly.  It  increases 
the  efficiency  of  your  Crosley  receiv- 
ing set,  notwithstanding  its  own  con- 
ventional form  and  that  it  is  different 
from  the  old  interlocking  plate  type. 


New  Crosley  Socket — 50c 

A  smaller  and  neater  socket 
now  replaces  the  old  porcelain 
one.  It  has  the  unique  feature 
of  base  and  panel  mounting 
found  only  in  Crosley  sockets. 
(Patent  pending).  It  fits  per- 
fectly and  has  the  highest 
dielectric  qualities. 


Model  XV— Price  §150 
A  console  cabinet  model  which  is  a  combination  of  effi- 
ciency and  beauty.    This  is  designed  for  homes  and  clubs 
where  a  complete,  long-distance  set  is  required.  Equipped 
with  compartment  for  batteries  and  loud  speaker. 


New  Crosley  Multistat— 80c 


This  multistat,  of  from  0  to  20 
ohms  resistance,  will  take  care  of  all 
types  of  tubes  with  its  high  and  low 
resistance  wire.  This  unit  solves 
the  problem  of  filament  control  on 
different  tubes.  The  smooth  run- 
ning, ball  bearing  contact  is  con- 
tinued. 


For  Sale  by  Best  Dealers  Everywhere 
Free  Catalogue  on  Request 


Better -Cost  Less 

Radio  Products  III 


■Jc  Tested  and  approved  by  Radio  Broadcast  -fa 


Radio  Broadcast 


ARTHUR  H.  LYNCH,  Editor 


CONTENTS  FOR  SEPTEMBER,  1923 

"Heariri  Things  at  Night"    -   -   -   -  Frontispiece 

THE  MARCH  OF  RADIO    -   --   --   --   --   --   --   --  -    J.  H.  M.  359 

SET-BACKS  AND  COME-BACKS  AT  6KW   -------     Frank  H.  Jones  368 

PAPERS  OF  THE  RADIO  CLUB  OF  AMERICA,  II 

The  Thoriated  Tungsten  Filament   ------   ^   -----  W.  C.  White  375 

10,000  MILES  OF  RADIO  LECTURES  IN  CHINA    -    -  Charles  H.  Robertson  382 

WANTED:  A  DESERT  ISLAND!  -------------     Zeh  Bouck  391 

HOW  VACUUM  TUBES  ARE  MADE       ---------  w.  W.  Rodgers  397 

SOME  NOTES  ON  TUNED  CIRCUITS  -   -   -   -    M.  B.  Sleeper  404 

A  LITTLE  FORESIGHT  AND  A  BIG  SUCCESS    -   -   -    -    Alfred  M.  Caddell  406 

HIGHLIGHTS  IN  THE  HISTORY  OF  WDAP   -----      J.  Elliott  Jenkins  411 

"MUSIC  HATH  CHARMS  "    ------------------  4i 5 

RECEIVING  CONTEST  WINNERS  -----------------  4I6 

In  Tune  with  the  Infinite   -----    -     Eric  G.  Shalkhauser  {Second  Pri(e)  417 

Hearing  North  America  -    -       -   -   -    -    Miss  Abbye  M.  White  (Third  Pri^e)  421 

The  World  at  Your  Finger  Tips  ------      H.  Blumenfeld  (Fourth  Pri^e)  426 

BROADCASTERS  IN  NEW  YORK,  PARIS,  AND  LOS  ANGELES  ------  429 

WHAT  YOU  SHOULD  KNOW  ABOUT  CONDENSERS,  I    -  Allen  D.  Cardwell  430 

THE  GRID— QUESTIONS  AND  ANSWERS   --------------  435 

ADDITIONAL  BROADCASTING  STATIONS  IN  THE  UNITED  STATES    -    -   -  438 

NEW  EQUIPMENT  -  -       -------------  .  440 

AMONG  OUR  AUTHORS  -   -   -   -  ------------  442 

Copyright,  1923,  by  Doubleday,  Page  &  Co.    All  rights  reserved 
TERMS:  $3.00  a  year;  single  copies  25  cents 
F.  N.  Doubleday,  Pres.  Arthur  W.  Page,  Vice-Pres.  Nelson  Doubleday,  Vice-Pres. 

Russell  Doubleday,  Sec'y.  S.  A.  Everitt,  Treas.  John  J.  Hessian,  Asst.  Treas. 

DOUBLEDAY,  PAGE  &  CO. 

The  World's  Work       Country  Life       The  Garden  Magazine       Short  Stories       Educational  Review 
CHICAGO.  People's  Gas  Bldg.  GARDEN  CITY,  N.  Y.  NEW  YORK:  120  W.  32nd  Street 

BOSTON:  Tremont  Bldg.  LOS  ANGELES:    Van  Nuys  Bldg 


RADIO  BROADCAST  ADVERTISER 


Radiotron 
UV-201-A 

The  super-amplifier 
tube  $6.50 


Radiotron  UV-20V 

The  long  distance  de- 
tector $5.00 


Radiotrons 

To  Get  Distance — 


This  symbol 
of  quality  is 

your  protec-  Radiotron 
tion  WD-12 

The  standard  base 
dry  cell  tube 
$6.50 


and  Get  it  Clearly 


For  quality  of  reception  and  length  of  ser- 
vice, every  fellow  wants  a  RADIOTRON. 
Experienced  amateurs  and  broadcast  lis- 
teners know  the  sensitivity  and  dependable 
performance  of  these  tubes.  UV-199  for 
portable  sets  because  it  operates  on  flash- 
light batteries.  WD-11  and  WD-12,  the  dry 
cell  tubes,  for  use  everywhere — especially 
on  farms  and  at  the  summer  bungalow — ■ 
UV-200  and  UV-201-A  for  use  with  a  storage 
battery.  There  is  a  Radiotron  for  every  need. 

Look  for  the  RCA  trade  mark,  and  the 
name  RADIOTRON.  Each  is  a  guarantee 
of  satisfaction. 

Radio  Corporation  of  America 

Sales  Dept.,  Suite  2066 
233  Broadway,  New  York 
District  Sales  Offices 
10  So.  LaSalle  St.  433  California  St. 

Chicago,  111.  San  Francisco.  Cal. 


Radiotrons 


REG.  U    S.  PAT.  OFF. 


-fa  Tested  and  approved  by  Radio  Broadcast  if 


Photograph  by  Roger  B.  Whitman 

"hearin'  things  at  night" 

This  clearing  in  the  woods  was  filled  with  music  from  a  four-tube  reflex  receiver 
perched  on  a  tree-stump.    The  Scouts  are  members  of  Troop  55,  Garden  City,  L.  I. 


AUG  21  1923  ©C1B  583707 


RADIO 
BROADCAST 

Vol.  3   No.  $  September,  1923 

The  March  of  Radio 

PRESIDENT  HARDING  OVER  WIRE  AND  RADIO 


THE  cooperation  of  wire  and  radio  is 
undoubtedly  a  development  which 
will  prove  of  inestimable  importance 
in  putting  the  vast  multitudes  of  this 
country  in  close  touch  with  its 
important  events.  Many  important  happen- 
ings occur  where  there  is  no  radio  station, 
events  which  cannot  be  brought  to  the  studio. 
But  few  and  far  between  are  the  events  which 
the  telephone  engineer  cannot  reach,  if  the 
occasion  demands.  The  vast  network  of  wires 
throughout  the  country  is  of  such  fine  mesh 
that  few  places  where  anything  important  is 
likely  to  happen  are  more  than  a  few  miles  from 
wire  connection.  With  a  good  wire  connection, 
the  distant  radio  station  is  enabled  to  broad- 
cast its  message  almost  as  well  as  if  the  event 
transpired  in  the  studio. 

We  said  "a  good  wire  connection,"  and  this 
means  more  than  the  average  reader  prob- 
ably surmises.  The  ordinary  telephone  and 
telegraph  wires  are  entirely  unsuited  for  send- 
ing the  voice  currents  to  the  broadcasting 
station.  Their  transmission  is  much  too  poor 
in  quality,  and  in  addition  they  pick  up  much 
extraneous  "electrical  noise."  The  engineers 
of  the  American  Telephone  and  Telegraph 
Company  have  studied  this  problem  in  its 
most  minute  details:  both  theoretically  and 
experimentally  the  staff  has  attacked  the 
question  as  to  what  good  voice  transmission 
really  is,  and  how  to  get  it.  They  can  tell 
you  all  about  the  different  "energy  levels"  of 


noise  and  voice  currents  for  different  kinds  of 
telephone  lines,  and  they  have  found  out  that 
only  the  highest  grade  telephone  lines  may  be 
used  in  their  long-distance,  transcontinental 
circuits.  Even  these  best  quality  lines  must 
be  improved  before  they  are  suitable  for  carry- 
ing the  voice  currents  to  a  broadcasting  station. 
The  wires  must  be  "balanced"  to  get  rid  of 
disturbing  noises,  fitted  with  "repeaters" 
which  will  amplify  the  voice  currents  and  yet 
keep  the  original  quality  of  the  voice  un- 
impaired, and  equipped  with  duplicate  appa- 
ratus to  ensure  continuity  of  service.  All  these 
items  are  being  worked  out  in  such  a  way  that 
before  long  the  telephone  company  will  have  a 
network  of  high  grade  "radio  wires"  available 
for  operating  the  various  broadcasting  stations 
it  will  probably  erect. 

An  excellent  test  and  illustration  of  the  value 
of  this  service  was  recently  given  when  Presi- 
dent Harding's  speech  was  sent  from  St.  Louis 
to  New  York,  and  there  broadcasted  from 
station  WEAF.  The  voice  currents  had  to 
travel  about  a  thousand  miles  before  actuating 
the  control  of  the  radio  transmitter,  yet  the 
articulation  was  excellent,  considering  the 
long  route  taken  by  the  voice  before  it  reached 
the  listener-in. 

This  is  one  of  the  marvels  which  radio 
engineers,  with  vision,  have  been  predicting 
for  a  year  or  two — the  President  addressing 
his  countrymen — not  a  few  hundred  or  thou- 
sand in  the  most  capacious  hall  obtainable. 


360 


Radio  Broadcast 


SPEAKING  TO  THE  NATION  FROM  ST.  LOUIS 

In  his  address  of  June  21st  at  the  St.  Louis  Coliseum, 
President  Harding  said:  "It  has  seemed  to  me  that 
nearly  every  city  and  village,  from  the  Potomac  to  the 
Pacific,  has  bestowed  an  invitation  and  a  tender  of  hos- 
pitality. I  would  like  to  say  to  you,  because  in  saying  it 
to  you  I  am  speaking  to  many  others  in  this  marvelous 
age  of  communication,  that  I  very  genuinely  regret  the 
impossibility  of  accepting  all  of  them.  Quite  apart  from 
the  personal  satisfaction  and  renewed  assurance  in  direct 
contact  with  our  people,  I  think  that  there  is  vast  benefit 
in  bringing  the  Government  a  little  closer  to  the  people, 
and  the  people  a  little  closer  to  the  Government  and 
closer  to  those  temporarily  charged  with  official  re- 
'  sponsibility." 

but  actually  millions  of  them.  While  a 
conservative  estimate  would  put  the  number 
of  the  President's  audience  at  a  few  hundred 
thousand,  it  seems  quite  possible  that  at  least 
a  million  people  heard  him  speak.  If  so  many 
did  not  hear  him,  they  could  have  done  so  had 
they  desired. 

In  this  experiment,  only  a  few  broadcasting 
stations  transmitted  the  President's  speech 
but  as  soon  as  the  high-grade  telephone  net- 
work can  be  developed  economically,  such  a 


speech  will  be  sent  out  on  different  wavelengths 
by  enough  powerful  radio  stations,  strategically 
located,  so  that  it  will  be  possible  actually,  not 
figuratively,  for  the  Chief  Executive  to  address 
all  of  his  countrymen. 

Still  Trouble  from  Interference? 

IN  OUR  last  issue  we  gave  out  the  glad  tidings 
that  "interference  had  been  done  away 
with" — that  the  new  schedule  of  frequencies 
which  the  Department  of  Commerce  had 
allotted  to  the  various  broadcasting  stations 
has  remedied  all  the  trouble  which,  for  so 
long,  had  harassed  the  radio  listener. 

The  opinion  was  based  first,  on  our  general 
knowledge  of  what  should  interfere  and  what 
should  not,  and  next,  and  more  important,  on 
the  basis  of  our  observations.  As  we  mentioned 
in  last  month's  editorial,  the  better  class  of  am- 
ateurs have  been  able  to  get  rid  of  interference 
even  when  the  stations  were  only  ten  meters 
apart,  or  only  five  (even  this  very  small  margin 
being  a  frequency  separation  of  about  fifteen 
kilocycles)  but  these  listeners  were  not  consid- 
ered when  we  gave  it  out  as  welcome  news  that 
the  wavelength  separation  for  closely  adjacent 
stations  in  the  new  assignment  was  about  fifty 
meters.  With  a  good  regenerative  receiver 
this  is  about  five  times  the  margin  necessary 
for  non-interfering  signals,  but  of  course  a  good 
many  people  do  not  have  regenerative  re- 
ceivers, and  many  of  them  who  do  are  not  able 
to  make  them  perform  as  they  should.  With 
this  idea  in  mind  we  investigated  the  inter- 
ference, with  the  new  schedule,  on  a  non- 
regenerative  receiver,  using  a  triode  detector 
and  two  circuits  for  tuning.  The  antenna  has 
tuning  of  its  own,  by  means  of  a  step  coil  and 
variable  condenser,  and  coupled  to  the  antenna 
circuit  (by  a  vario-coupler)  is  the  second  tuned 
circuit  to  which  the  detector  is  connected. 
At  a  distance  of  about  ten  miles  from  three 
stations,  rated  at  405,  455,  and  492  meters 
respectively,  there  is  no  interference!  Using  a 
loud  speaker,  and  adjusting  the  set  to  give  a 
signal  from  one  of  the  stations  loud  enough  to 
be  audible  throughout  the  house,  by  means  of 
the  audio-frequency  amplifier,  the  signals 
from  the  other  stations  were  so  weak  that  the 
ear  had.  to  be  held  quite  close  to  the  loud 
speaker  before  they  were  even  audible.  That's 
what  we  called  "no  interference". 

In  talking  with  one  of  our  well  known  radio 
inspectors,   however,   we  found   that  many 


The  March  of  Radio 


361 


people  still  report  interference;  in  fact,  some  go 
so  far  as  to  say  the  old  schedule  was  better — 
that  only  one  station  should  be  allowed  to  send 
at  a  time.  Of  course,  this  is  nonsense,  the  new 
schedule  is  a  real  step  in  advance  and  the 
Department  of  Commerce  is  to  be  commended 
in  having  taken  it.  What,  then,  is  the  matter 
with  these  people  reporting  interference?  In 
general,  we  can  say  their  sets  are  certainly  not 
operating  as  they  should,  or  else  the  set  is  too 
crude  to  be  considered  as  a  real  radio  receiver. 
Those  sets  made  of  a  few  turns  of  wire  on  an 
oatmeal  box,  with  a  crystal  and  telephone 
shunted  around  the  coil,  are  not  considered  in 
this  argument.  Interference  undoubtedly  does 
occur  in  many  sets  of  this  kind,  but  complaints 
from  such  sources  should  receive  but  little 
consideration  from  the  radio  inspector  trying 
to  satisfy  the  public.  Radio  to-day  has  ad- 
vanced sufficiently  to  warrant  a  fairly  selective 
receiver;  if  the  set  is  non-regenerative,  tjvo 
tuned  circuits  should  be  used,  with  compara- 
tively weak  coupling,  and  if  a  regenerative  set 
is  used,  those  operating  them  must  study 
their  action  sufficiently  to  get  reasonable 
selectivity. 

1  To  be  sure,  there  are  a  few  listeners  who  will 
undoubtedly  report  interference,  even  after 
observing  all  precautions.  A  few  members 
of  the  radio  audience  live 
throw  of  one  of  the  broad- 
casting stations.  They  are 
really  "out  of  luck,"  be- 
cause the  signal  from  the 
neighboring  station  will  be 
able  to  drown  out  the  distant 
stations  even  if  the  two  sig- 
nals are  a  hundred  meters 
apart.  In  such  cases  only 
expert  adjustment  of  an  es- 
pecially selective  set,  and  the 
use  of  absorbing  circuits,  can 
eliminate  interference.  For- 
tunately only  a  small  per- 
centage of  the  radio  listeners 
are  so  situated. 

Preparing  for  Long 
Distance 


within  a  stone's 


had  from  a  radio  receiver  is  found  in  our  ability 
to  astound  our  friends  by  tuning  in  a  pro- 
gram a  thousand  or  more  miles  away  for 
their  particular  benefit.  This  mild  method  of 
"showing  off"  is  sure  to  find  disciples  among 
us  mortals  for  some  little  time  to  come. 

There  is  something  fascinating  about  hearing 
a  concert  from  a  long  way  off,  and  the  pleasure 
does  not  seem  to  wane  with  familiarity.  Some 
of  the  old  ship-  operators  spend  much  of  their 
spare  time  listening  for  distant  broadcast  sta- 
tions, much  as  the  proverbial  letter  carrier, 
on  his  day  off,  takes  a  little  walk.  Among  the 
radio  manufacturers,  merchants,  and  writers 
whom  it  is  our  privilege  to  know,  there  are 
many  who  feel  a  holiday  or  a  vacation  incom- 
plete unless  they  have  a  radio  receiver  with 
them  in  order  to  compare  the  reception  at  dis- 
tant points  with  the  results  they  obtain  at  home. 

And  now,  when  the  days  are  still  long  and 
there  is  more  time  for  us  to  devote  to  radio 
than  is  possible  in  winter,  would  it  not  be  wise 
for  us  to  give  a  thought  to  the  long-distance 
receiver  we  will  want  for  use  when  the  weather 
makes  the  care  of  a  good  fire  and  radio  a  most 
attractive  pair  of  indoor  sports? 

Now  is  the  time  to  begin  work  on  that  power 
amplifier,  or  super-heterodyne,  or  reflex  receiver 
for  use  at  home  or  in  connection  with  various 
jamborees  to  be  held  by  the  sons  or  daughters 


DESPITE  all  argu- 
ments to  the  con- 
trary, we  are  of  the 
belief  that  a  great  deal  of 
the  enjoyment  which  is  to  be 


AN  INTERESTED  GROUP  AT  LONG  BEACH,   L.  I. 
Frank  M.  Squire,  Chief  Engineer  of  the  De  Forest  Company,  (standing  just  behind 
the  bulldog)  is  trying  a  new  model  receiver,  developed  by  him,  which  works  a 
loud  speaker  from  the  small  circular  loop  shown  just  to  the  left  of  the  horn 


362 


Radio  Broadcast 


of  Something-or-Other  to  be  given  in  the  fire  reliable  newspapers  to  such  articles  as  the  one 
house  or  the  town  school  next  winter.  Dane-  before  us — "  Deaf  ears  hear  again  through  the 
ing  to  music  played  by  an  orchestra  a  thousand  magic  of  radio."  As  the  article  consists  largely 
miles  away  is  now  possible — if  you  have  the  of  an  interview  with  a  deaf  person  who  had 
proper  receiver  in  good  shape.  Are  you  put-  heard  radio  signals  the  article  is  apparently 
ting  your  radio  house  in  order  for  the  good  a  confirmation  of  the  idea  conveyed  by  the  head- 
times  that  are  coming?  lines. 

How  then  does  radio  help  these  deaf  people? 

"Deaf  Ears  Hear  Again"  Simply  in  this  way:  in  the  development  of  radio 

it  has  been  found  necessary  to  have  amplifiers, 

THERE  have  recently  appeared  several  the  same  kind  of  amplifiers  as  have  been  used 
reports  to  the  effect  that  people  who  for  the  past  ten  years  by  the  telephone  engi- 
have  been  deaf  all  their  lives  have  been  neers  in  all  their  long-distance  lines;  by  means 
able  to  hear  by  means  of  radio  apparatus;  and  of  these  amplifiers,  which  the  average  person 
the  achievement  was  heralded  as  one  of  radio's  naturally  thinks  of  as  radio,  extremely  loud 
greatest  triumphs.  We  pointed  out  that  a  sounds  can  be  produced,  as  witness  the  loud 
mistake  had  surely  been  made — sound  was  speakers  frequently  used  in  large  lecture  halls 
sound,  and  after  the  sound  waves  had  left  the  by  the  "public  address"  engineers  of  the  tele- 
diaphragm  of  the  telephone  it  was  a  matter  of  phone  companies.  Now  evidently  amplifier 
no  consequence  to  the  ear  drum  whether  the  vi-  systems  are  exactly  what  the  average  deaf 
bration  of  the  diaphragm  was  caused  by  a  radio  person  needs.  Probably  many  "deaf"  people 
signal  or  by  ordinary  wire  telephone  currents,  are  not  absolutely  deaf — loud  enough  signals 
It  seems  worth  while  to  point  out  this  fact  might  well  be  audible  to  them  no  matter  how 
again  in  view  of  the  importance  given  by  hardof  hearingthey  might  be.  This  is  what  radio 


CHIEF  RADIO  OFFICER  E.  N.  PICKERILL  IN  THE  OPERATING  ROOM  OF  THE  "  LEVIATHAN  " 
Uninterrupted  service  with  points  3,000  miles  away  is  claimed  for  this  ship's  radio  apparatus 


The  March  of  Radio 


363 


 .  ,  .  .  *  •   .  -,  ,  ;" "  *   :  ,  ,  ;  —  '  "  *"  

©  Underwood  &  Underwood 

THE  "LEVIATHAN" — SHE  CARRIES  THE  MOST  POWERFUL  RADIO  EQUIPMENT  OF  ANY  SHIP 

The  "duplex  "  system  of  radio  telephony,  whereby  conversations  may  be  carried  on  as  over  a  land  line — with- 
out changing  from  "send  "  to  "receive" — has  been  installed  on  this  floating  hotel  by  the  Radio  Corporation 


is  doing  for  the  deaf;  enabling  them  to  apply  to 
their  ear  drums  signals  perhaps  ten  thousand 
times  as  loud  as  the  ordinary  person  requires 
for  normal  hearing.  Such  amplifying  systems 
are  entirely  apart  from  radio  in  the  strict  sense 
of  the  term,  however.  The  same  apparatus 
attached  to  the  ordinary  telephone  line  would 
permit  the  deaf  to  hear  ordinary  telephone 
conversation  perfectly  well,  and  yet  this  would 
evidently  not  be  an  achievement  of  radio. 

We  must  remember,  however,  that  radio 
makes  available  to  the  deaf,  concerts,  pro- 
grams, and  speeches,  in  such  form  that  the 
amplifying  apparatus  is  able  to  strengthen  it 
sufficiently  for  their  hearing.  Thus  even 
though  the  radio  waves,  as  such,  do  nothing  to 
make  the  deaf  hear,  the  apparatus  associ- 
ated with  radio  has  no  doubt  proved  a  great 
boon  to  them.  If  one  is  very  deaf,  a  good  deal 
of  amplification  is  necessary;  one  person  known 
to  us  has  a  five-tube  amplifier,  and  wears  head 
phones!  As  he  says,  "it  costs  money  if  you're 
very  deaf."  So  delighted  was  he  actually  to 
hear  that  he  burned  up  two  of  his  tubes  the 
first  hour,  trying  to  increase  this  amplification. 

A  real  advantage  of  this  use  of  the  amplifier 
is  that  by  using  the  head  phones,  the  deaf  per- 
son can  have  his  signals  as  loud  as  he  wants 
them;  yet  people  around  him  are  not  disturbed, 


or  even  aware  of  the  extremely  loud  signal  to 
which  he  is  listening. 

It  is  possible,  too,  that  the  continued  use  of 
greatly  amplified  signals  beating  upon  the  ear 
drums  will  cause  the  organs  associated  with 
hearing  to  improve,  due  to  exercise.  We  know, 
for  instance,  that  a  broken  arm  or  leg,  after 
being  held  in  a  plaster  cast  for  a  long  period  is 
difficult  or  impossible  to  use  immediately  after 
the  cast  has  been  removed.  But  when  the 
newly  knitted  member  is  exercised  periodically, 
the  muscles  gradually  become  stronger  and  we 
find  that  the  member  may  be  used  quite  as  well 
as  it  could  before  the  period  of  inaction  began. 
Some  interesting  experiments  are  being  carried 
on,  taking  advantage  of  this  method  for 
improving  hearing,  and  some  favorable  reports 
of  the  results  obtained  have  reached  us.  It  is 
a  very  worth-while  undertaking  and  should  be 
encouraged. 

Marconi  Making  Progress  With 
His  Short  Waves 

ABOUT    a    year    ago    Senator  Marconi 
/\     reported   before   a  joint  meeting  of 
£    V  radio  and  electrical  engineering  socie- 
ties, at  a  meeting  in  New  York  City,  his 
interesting  and  apparently  promising  experi- 


364 


Radio  Broadcast 


A   COIN-BOX    BROADCAST   RECEIVER   IN  PARIS 

In  some  of  the  Parisian  cafes,  movie  houses,  hotels,  and 
other  public  places  are  now  found  "Radio-Automatic" 
stations  at  which  any  one  may  listen-in  on  broadcasting 
programs  for  a  few  centimes,  at  times  indicated  on  a 
chart  hung  near  the  instrument 

ments  in  short-wave  radio.  He  showed  ex- 
perimentally how  the  short  waves  could  be 
reflected  by  an  "electrical  mirror"  and  sent  in 
any  desired  direction,  like  light  waves,  and  how 
easily  they  might  be  absorbed.  There  was 
nothing  new  in  these  special  experiments, 
Hertz  having  done  exactly  similar  ones  in  his 
laboratory  thirty-odd  years  previously,  but 
the  experiments  did  indicate  to  the  large  and 
enthusiastic  audience  how  Hertz's  laboratory 
experiments  on  short  waves  might  be  turned  to 
practical  use.  It  was  evident  to  every  one 
that  if  radio  waves  could  be  confined  to  one 
direction,  instead  of  spreading  out  in  all  direc- 
tions, much  less  power  would  be  required  and 
much  interference  would  surely  be  eliminated. 

From  a  recent  interview  given  by  Marconi 
to  the  London  press  it  appears  that  he  has  been 
applying  himself  to  the  problem  with  very 
successful  results.  Although  he  did  not  men- 
tion short  waves  as  the  means  he  employed, 
reading  between  the  lines  of  his  interview,  we 
are  forced  to  conclude  that  such  was  the  case. 
"  We  have  transmitted  messages  up  to  a  dis- 
tance of  2,500  miles,  not  only  with  much 
smaller  power,  but  also  far  more  cheaply  than 
with   the  ordinary  system  of  long-distance 


wireless,"  he  said.  "To  send  the  message 
2,500  miles  took  less  power  than  the  ordinary 
message  from  London  to  Paris.    .    .  ." 

Our  best  wishes  are  extended  to  the  radio 
pioneer  in  this  new  field  he  is  developing.  We 
should  ourselves  be  doing  more,  in  this  country, 
to  open  up  this  unexplored,  but  very  promising, 
field  of  radio  transmission. 

Radio  an  Auto  Accessory  in  Jolly  Old 
England 

EVERY  potential  buyer  of  a  modern 
motor  car  knows  that  long  list  of 
"accessories."  They  bristle  all  over 
the  specification;  they  crop  up  in  the  selling 
price;  but  in  the  car  itself  they  are  models 
of  unobtrusiveness.  Some  of  them  are  absolute 
necessities:  a  good  many  of  them  are  not. 
Attractive  accessories,  contrived  to  add  just  a 
degree  more  of  comfort  and  convenience  for 
the  user,  are  constantly  being  devised  by 
makers  who  see  in  them  an  additional  some- 
thing to  sell. 

It  was  therefore  to  be  expected  that  with  the 
recent  rapid  development  of  wireless  broad- 
casting and  the  perfection  of  portable 
"listening-in"  sets,  motor  car  manufacturers 
would  soon  be  considering  the  adaptability 
of  yet  another  luxurious  accessory.  The 
Daimler  Company  was  quick  to  realize  the 
possibilities  of  carrying  a  portable  wireless  set 
on  its  cars,  and  the  Marconi  Company,  doubt- 
less with  business  prospects  also  in  mind,  has 
combined  with  it  to  overcome  some  of  the 
technical  problems  involved. 

In  October  of  last  year  two  Daimler  landau- 
lettes  made  a  reasonably  successful  experi- 
mental run  from  London  to  Chelmsford  and 
back,  fitted  with  an  installation  which  appears 
crude  in  comparison  to  recent  achievements. 
Their  biggest  problem  was,  of  course,  the 
antenna.  As  everyone  who  is  interested  in 
wireless  is  aware,  the  height  of  the  antenna 
which  picks  up  the  transmitting  station's 
signals  has  a  great  bearing  upon  the  ability  of 
the  vacuum  tube  to  produce  clear  sounds  in  the 
receiver.  A  traveling  motor  car  is,  obviously,  no 
place  for  an  antenna  of  more  than  insignificant 
height,  so  that  the  first  experiments  were  made 
with  an  ingenious  contrivance,  shaped  rather 
like  a  catherine-wheel,  and  mounted  pivotally 
to  the  roof  of  the  car.  This  was  actuated  by  a 
small  hand  wheel  which  rotated  the  antenna 
through  a  certain  number  of  degrees,  and  so 


The  March  of  Radio 


365 


was  able  to  obtain  the  best  results  from  sig- 
nals coming  from  all  points  of  the  compass. 
By  this  means  a  directional  value  was  given 
to  it,  which  compensated  for  loss  of  height. 
When  not  in  use  it  could  by  means  of  the 
same  hand  wheel  be  folded  down  to  lie  flat  upon 
the  roof  of  the  car. 

In  any  case,  the  antenna  was  unsightly  and 
very  much  in  the  way,  so  the  experimenters 
quickly  evolved  a  flat  antenna  consisting  of  a 
copper  plate,  suspended  and  insulated  from 
the  luggage  rail  on  the  car  top  at  eight  points. 
This,  it  was  found,  overcame  all  the  receiving 
difficulties  and  proved  actually  more  efficient 
than  the  frame  antenna.  Later  it  was  found 
possible  to  build  it  into  the  car  between  the 
coachwork  of  the  roof  and  the  upholstery. 
From  the  centre  of  the  lower  side  of  the  copper 
plate,  lead-in  wires  passed  down  to  the  receiving 
set  within  the  car. 

In  the  earlier  models,  the  tuning  appara- 
tus was  in  the  form  of  a  vertical  projection, 
rather  awkwardly  placed,  and  having  three 


controls.  This  has  been  replaced  by  an  eight- 
tube  receiving  set  (five  radio-frequency,  a 
detector,  and  two  A.  F.  amplifiers),  neatly 
and  compactly  enclosed  in  a  small  upholstered 
box  to  the  left  of  the  back  seat.  Four  people 
can  listen-in  on  this  set  at  the  same  time, 
using  either  one  of  the  light  single  earpiece 
receivers  provided,  or,  if  they  prefer  it,  the 
ordinary  double  head-phones. 

Another  problem  was  the  disturbing  influence 
set  up  by  the  ignition  apparatus  of  the  car 
itself.  Each  spark-plug  was  found  to  be  a 
miniature  transmitter,  throwing  off  waves 
which  could  plainly  be  heard  in  the  receivers. 
This  has  been  overcome  by  enclosing  the 
magneto  in  a  copper  box,  and  each  spark  plug 
in  a  copper  sheath.  Moreover,  each  high 
tension  wire  is  run  through  a  flexible  copper 
casing,  the  copper  in  every  case  serving  to 
ground  the  disturbing  waves  and  minimize 
their  effect. 

As  a  motor  car  is  insulated  from  the  roadway 
by  its  tires,  the  next  problem  was  to  devise  an 


Harris  &  Ewing 

HERE  MESSAGES  ARE  SENT  AND  RECEIVED  THROUGHOUT  THE  WORLD 
T  he  Radio  Central  room  of  the  U.  S.  Navy  Department.    Communications  are  transmitted  to  Lyons,  London,  Balboa, 
and  to  fleets  operating  near  Constantinople.    This  station  has  picked  up  a  message  from  Cairo,  Egypt.  The 
"clarophone,"  or  static  eliminator,  invented  by  W.  J.  Scott  of  the  Navy  Department,  is  seen  in  the  background  (small 

cylinders  projecting  from  a  large  horizonal  cylinder) 


366  Radio  Broadcast 


RECEIVING  FIVE  CONCERTS  AT  ONCE  WITH  SUPER-HETERODYNES 
Claude  Golden  in  the  Research  Laboratory  of  the  Experimenters'  Information  Service, 
New  York,  tuning  in  on  Pittsburgh,  Chicago,  Schenectady,  New  York,  and  Cleveland 


efficient  "ground."  They  soon  found  that 
the  frame  of  the  car  made  what  is  called  a 
"capacity  ground,"  which,  although  not  so 
efficient  as  a  true  "  ground,  "  served  the  purpose 
very  well  indeed. 

The  A  and  B  batteries  and  valve  panel  are 
neatly  and  cleverly  put  away  out  of  sight 
between  the  floor-board  and  the  chauffeur's 
seat.  No  technical  knowledge  whatever  is 
required  to  operate  the  tuning  controls  con- 
tained in  the  small  upholstered  box  to  the  left 
of  the  back  seat:  only  the  simplest  operations 
are  necessary  to  achieve  excellent  results. 

So  efficient  has  this  apparatus  proved  that 
the  Daimler  Company  proposes  to  build  plate 
antenna  into  the  roofs  of  all  their  cars  as 
standard  fittings,  so  that  the  purchaser  who 
wants  to  install  a  wireless  will  have  his  antenna 
ready  at  hand. 

The  Daimler  Hire  Ltd.,  of  London,  has 
already  installed  sets  in  fifteen  of  its  fleet  of 
250  cars,  and  so  great  has  the  demand  been  for 
them,  that  the  company  is  busily  engaged  in 
fitting  more.  "2LO, "  the  London  station 
of  the  British  Broadcasting  Company  has  been 
heard  clearly  and  distinctly  from  Southampton 
on  one  of  these  cars,  while  only  the  other  day 


a  car  on  the  road  in  the  neighborhood  of 
Uxbridge  picked  up  signals  from  a  station  at 
Newcastle. 

As  an  "attractive  accessory,"  the  wireless 
set  has  undoubtedly  come  to  stay:  how  soon 
the  portable  transmission  set  follows  it  remains 
to  be  seen.  At  the  present  rate  of  develop- 
ment, what  is  now  but  an  ingenious  pastime 
may  soon  pass  into  the  sphere  of  commercial 
usefulness. 

"Frate  Sole"  Is  Carried  Across  Continent 
to  Composer's  First  Instructor 

PROBABLY  not  more  than  a  dozen 
persons  were  cognizant  of  the  drama 
of  the  air  that,  according  to  the  San 
Francisco  Chronicle,  was  enacted  recently,  when 
Giuseppe  Bartalo,  aged  teacher  of  Luigi  Man- 
cinelli,  author  of  the  motion  picture  opera 
"  Frate  Sole,"  which  was  presented  at  the  Civic 
Auditorium  in  San  Francisco,  heard  in  New 
Orleans  his  pupil's  last  composition,  broad- 
casted from  station  KPO  in  San  Francisco. 

It  was  Bartalo  who,  many  years  ago,  shaped 
the  musical  foundation  of  Luigi  Mancinelli 
in  far-off  Milan,  when  the  little  boy  with  the 


The  March  of  Radio 


367 


serious  eyes  came  to  him  for  his  initial  instruc- 
tion. Proudly  he  watched  the  fruits  of  his 
labors,  as  Mancinelli  developed  into  a  composer 
whose  operatic  and  symphonic  scores  were 
familiar  to  thousands. 

While  Mancinelli  was  climbing  to  fame, 
Bartalo  was  establishing  himself  in  America. 
The  roads  of  pupil  and  teacher  parted.  Man- 
cinelli rose  high  in  his  profession,  but  he  never 
forept  the  instructor  to  whom  he  owed  his 
early  training  and  encouragement.  Frequently 
he  wrote  him,  and  sent  him  copies  of  his  newest 
scores.  And  Bartalo's  breast  would  swell  with 
pride,  and  he  would  tell  his  friends  tales  of 
his  Luigi  as  he  always  remembered  him. 

In  1922,  Mancinelli  died.  Bartalo  was  heart 
broken.  He  collected  all  of  his  pupil's  works 
that  he  could  find.  But  some  of  the  latest 
works  he  overlooked,  among  them,  "  Frate 
Sole,"  which  he  had  never  heard.  No  more 
had  America.  When  arrangements  were  made 
to  bring  "Frate  Sole"  to  this  country,  no  one 
thought  of  little  Bartalo,  down  in  New  Orleans. 

When  a  special  concert  was  arranged  through 
station  KPO,  so  that  the  radio  world  might 
hear  a  fragment  of  the  dead  composer's  work, 
friends  recalled  the  aged  maestro.  Telegrams 
were  exchanged  between  San  Francisco  and 
New  Orleans.  As  a  result  of  them,  little,  old, 
bent  Giuseppe  Bartalo  sat  at  a  receiving  set 
half  across  the  continent,  and  with  tears  stream- 
ing down  his  cheeks,  as  he  later  explained  by 
telegram  to  KPO  and  to  his  friends,  heard 
again  the  living  fire  of  "Little  Luigi." 

Private  Radiophone  Communication 

A RECENT  announcement  from  the  Bell 
System's  engineers  states  that  the 
famous  radio  link  in  their  telephone 
network,  connecting  Los  Angeles  with  Catalina 
Island,  is  soon  to  be  abolished,  as  the  radio 
service  is  not  as  economical  as  the  cable  service 
between  these  points.  Having  found  the  Key 
West-Havana  cable  service  satisfactory,  the 
telephone  company  has  decided  to  put  a  cable 
to  Catalina.  But  before  dismantling  the  radio 
plant  the  engineers  have  been  experimenting 
with  a  scheme  for  private  radio  telephone 
transmission — a  scheme  such  that  any  one 
not  "in  the  know"  could  not  decipher  it. 
The  experiments  are  said  to  have  been  success- 
ful to  the  extent  that  the  average  receiving  set 
could  hear  nothing  intelligible  from  the  station. 
It  seems,  however,  that  one  skilled  in  the  art 


could  soon  adjust  his  set  to  pick  it  up.  The 
system,  we  judge  from  the  interview  the  engi- 
neers gave,  is  not  similar  to  Marconi's  directive 
radiation  scheme  but  probably  one  which 
broadcasts  the  radio  signal  without  the  carrier 
wave;  as  this  is  necessary  to  make  an  in- 
telligible signal  it  must  be  put  back  into  the 
signal  at  the  receiving  station  and  if  one  did 
not  appreciate  this  fact,  the  speech  would 
indeed  be  "private."  If  our  guess  is  correct, 
this  scheme  is  far  from  being  private  because 
it  would  not  take  long  for  the  average  listener 
to  learn  what  to  do  to  his  set  to  put  the  requisite 
carrier  wave  back  in  to  the  received  signal. 

Service  is  Necessary 

IN  YOUR  own  sphere  of  acquaintances  how 
many  people  have  you  known,  who,  after 
procuring  a  radio  receiver,  could  secure  any- 
thing like  satisfactory  results  before  you  or  some 
other  person  versed  in  operation  showed  them 
how  to  adjust  the  knobs  properly?  Again,  how 
many  of  these  same  acquaintances  could  make 
head  or  tail  out  of  the  instruction  book  they 
received  with  their  outfit — if,  indeed,  they 
received  one? 

Inquiries  of  this  nature  among  our  own 
acquaintances  have  brought  home  the  need  for 
reliable  service  with  every  radio  receiver  put 
in  the  home.  We  believe  that  the  reliable 
radio  dealer  a  year  or  two  from  to-day  will 
find  that  the  sale  of  one  or  two  standard  lines 
of  complete  receivers  will  pay  him  well  enough 
to  allow  a  fair  profit  above  his  expenditures  and 
permit  him  to  give  the  desired  service  at  a 
comparatively  low  figure.  As  in  the  automo- 
bile business,  it  will  be  possible  for  him  to 
make  a  definite  charge  for  service  after  the 
guarantee  period  has  passed.  And  it  is  more 
than  likely  that  the  cost  of  supplying  service 
on  newly  installed  machines  may  be  kept  down 
to  a  minimum  by  sending  a  representative, 
capable  of  instructing  the  purchaser,  to  check 
up  each  installation  and  show  its  owner  how 
to  secure  the  best  results  from  it. 

Along  with  the  idea  of  service  comes  the 
thought  that  much  of  the  high-class  radio 
business  of  the  future  will  be  done  on  the  time 
payment  plan,  and  the  merchant  who  can 
secure  proper  financing  and  is  willing  to  convert 
service  from  a  liability  to  an  asset  by  advertis- 
ing it  properly  has  his  finger  on  the  latch  that 
will  open  the  door  to  prosperity  for  him. 

J.  H.  M. 


CHRISTMAS  DAY  AT  THE  HOME  OF  6KW 
Office  building  at  the  Tuinucu  Sugar  Company  plantation 

Set-Backs  and  Come-Backs  at 

6KW 

A  Story  of  the  Building  and  Operating  of  the  Well- 
Known  Amateur  Broadcasting  Station  in  Tuinucu,  Cuba 

By  FRANK  H.  JONES 


IN  1920,  when  the  Westinghouse  Company 
first  started  broadcasting  from  KDKA  and 
WJZ  for  local  listeners,  I  surprised  them  as 
well  as  myself  by  picking  them  up  clearly 
here  at  Tuinucu,  Cuba — a  distance  of 
1,250  miles — with  a  single-tube  regenerative 
circuit.  Later,  I  added  audio-frequency  ampli- 
fiers and  we  were  dancing  to  music  transmitted 
by  these  stations  before  they  could  believe  they 
were  reaching  out  more  than  a  few  hundred 
miles  at  best.  But  the  joke  was  really  on  me, 
for  I  thought  they  must  be  using  at  least  five 
or  maybe  ten  kilowatts,  and  you  can  imagine 
my  surprise  when  I  found  that  they  were  not 
using  more  than  §  kw.  We  heard  them  so 
well  at  times  that  for  all  the  1 ,250  miles  from 
KDKA   and    1,375    miles   from  WJZ,  the 


thought  took  root  in  my  mind  that  maybe  I 
could  reach  out  half  that  far  with  a  set,  say, 
of  100  watts,  carefully  constructed  and  ac- 
curately adjusted. 

In  December,  1921,  I  decided  to  make  the 
plunge  and  thought  that  all  1  had  to  do  was 
order  what  I  wanted,  set  it  up,  and  proceed  to 
startle  the  world.  I  ordered  all  the  necessary 
apparatus  to  make  a  100-watt  set,  using 
Kenotron-rectified  current  on  the  plates — that 
is,  two  50-watt  oscillator  tubes  and  two  50-watt 
Kenotron  rectifier  tubes,  planning  to  use 
magnetic  modulation,  this  being  considered 
simple  and  easy  to  operate. 

This  was  about  the  time  when  broadcasting 
started  to  boom,  and  I  then  had  my  first  of  a 
series   of   disappointments.    It   was  almost 


Set-Backs  and  Come-Backs  at  6KW 


369 


exactly  a  year  before  I  was  able  to  get  together, 
down  here  in  Cuba,  all  the  necessary  parts  for 
that  first  transmitter.  First  a  few  sockets 
came,  and  some  transformers;  then  a  long  wait 
and  some  condensers  and  Kenotrons;  then 
another  long  wait  and  some  more  condensers 
and  the  Radiotrons.  Then  I  would  find  that 
one  tube  had  arrived  with  a  broken  grid  and 
another  with  a  broken  filament.  It's  a  long 
way  down  here  and  the  boxes  receive  lots  of 
rough  handling.  It  seemed  as  though  the  fates 
were  against  me,  but  finally  the  great  day 
arrived  when  I  had  all  the  stuff  I  needed  at 
the  same  time  ! 

Of  course  I  had  already  put  up  an  antenna, 
having  planned  to  transmit  on  about  300 
meters.  I  used  an  inverted  L  200  feet  long 
with  a  series  condenser  to  get  down  to  300 
meters.  I  did  not  have  a  thermal  galvano- 
meter wavemeter,  but  just  a  buzzer  device 
which  I  had  used  to  calibrate  my  receivers,  and 
I  had  expected  to  be  able  to  employ  this  by 
using  my  calibrated  tube  receiver  as  a  wave- 
meter  with  phones.  It  was  truly  an  exciting 
moment  when  I  first  turned  on  the  current  with 
fond  expectations  of  having  to  buy  a  new  an- 
tenna ammeter  so  the  reading  woudn't  go  off 
the  scale  (I  had  a  meter  reading  0-5  amperes.) 

I  was  glad  I  had  no  expectant  audience,  for 
the  meter  needle  never  budged  a  hair's  breadth. 

Then  followed  industrious  retracing  out  of 
circuits  and  rechecking  approximate  calcu- 
lations I  had  made  on  the  various  values  of 
capacitance  and  inductance  to  give  me  the 
300-meter  wave.  The  circuits  all  checked  up 
O.  K.  From  then  on  I  sweat  blood.  I'll  bet, 
if  I  tried  one  combination  of  capacitance  and 
inductance  in  the  various  high-frequency  parts 
of  the  circuit,  I  tried  999,999.  Remember,  I 
had  no  laboratory  testing  meters  and  apparatus 
and  so  had  to  try  various  combinations — and 
try  them  carefully — so  as  not  to  burn  up  any 
apparatus.  Well,  to  cut  this  part  of  the  story 
shorter,  I'll  say  that  I  finally  made  a  very 
slight  change  in  the  inductance  value  of  one 
of  the  coils,  and  lo  and  behold,  I  had  a  radia- 
tion of  about  two  measly  tenths  of  an  ampere ! 
Eureka,  I  was  getting  along. 

But  what  was  the  wavelength? 

I  could  hear  the  ding  thing  all  over  my 
receiving  tuner. 

"Que  pasa?"  as  we  say  in  Spanish. 

Had  the  manufacturer  forgot  to  send  the 
wavelength,  or  had  there,  somehow  or  other, 
sneaked  in  too  many? 


THE  TRANSMITTER  PANEL  AT  TU1NUCU 


Well,  finally,  after  deep,  heavy,  thinking,  I 
decided  my  radiation  (?)  was  principally  on 
a  wave  somewhere  around  228  meters.  I 
asked  a  friend  living  about  1,000  feet  away,  if 
he  could  hear  me,  and  he  said  yes,  so  then  after 
calibrating  his  receiver,  I  asked  him  to  let  me 
know  what  wave  I  was  radiating.  He  said  he 
didn't  think  it  was  a  wave  at  all,  but  sounded 
more  like  a  buzz-saw. 

Some  people  always  try  to  be  funny  when 
you're  serious. 

1  finally  wrote  to  my  good  friend  Pierri  of 
R.  C.  A.  and  upon  his  advice  got  a  thermal 
galvanometer  wavemeter.  Oh  boy,  that's  the 
finest  piece  of  testing  apparatus  I  ever  had  my 
hands  on — quick  and  easy  to  operate — but 
they  sure  dent  your  pocket-book.  With  it 
I  began  to  get  somewhere.  I  found  I  was 
really  radiating  fairly  sharply  on  250  meters. 
It's  some  satisfaction  to  know  where  you're 
at,  even  if  you  don't  know  how  you  got  there 
nor  where  you  go  from  there. 

After  making  'steen  thousand  more  trials 
and  combinations  (incidentally  burning  out 
only  two  50-watters),  I  finally  boosted  my 
current  in  the  antenna  to  15  amperes. 


370 


Radio  Broadcast 


MR.  JONES  AT  HIS  RECEIVING  STATION 

From  here  the  telegraph  transmitter,  located  in  another  room,  is  operated  by  remote  control.  l.C.W. 
(interrupted  continuous  wave)  transmission  is  carried  on  under  the  call  letters  6XJ,  on  275  meters 


Viva  Cuba,  viva  yo,  viva  everybody! 

I  then  seemed  to  be  stumped.  But  I  came 
across  an  article  in  a  magazine  that  said  an 
earth  was  the  poorest  kind  of  a  ground,  or 
something  like  that.  My  pocket-book  was 
already  getting  flat  and  1  couldn't  think  of 
importing  any  special  dirt  from  U.  S.  dealers 
who  "guarantee"  everything  to  add  100 
per  cent,  efficiency  to  everything.  We  had  lots 
of  dirt  here,  and  I  had  always  thought  it  was 
pretty  dirty  dirt;  but  apparently  as  a  ground 
it  didn't  speak  the  right  language  for  radio. 

Curtain  after  great  gloom. 

Scene  Two:  Same  as  before. 

Enters  the  hero,  "Jack  Counterpoise." 

Well,  to  come  down  to  earth  (grounds)  again 
—  I  read  many  lines  on  how  not  to  construct  a 
counterpoise  and  then  discovered  1  would  have 
to  cut  down  all  the  nice  trees  around  our 
bungalow,  and  move  the  house  away  and  level 
off  the  ground. 

1  consulted  my  wife. 

Result:  house  stays  where  it  is  and  trees  also. 
Then  I  wished  that  my  little  son  Vincente 
would  turn  out  to  be  a  second  G.  W.  Without 
giving  him  any  hints,  for  one  has  to  be  honor- 


able with  one's  wife,  1  gave  him  a  nice  nickle- 
plated  hatchet  for  his  birthday  and  told  him  he 
mustn't  cut  the  trees.  (Tough  luck,  he  obeyed.) 

My  wife  said  she  had  read  lots  of  things  in 
books  that  she  knew  were  not  true,  so  maybe 
the  ones  who  wrote  about  counterpoises  didn't 
know  everything,  either.  She  said,  "Why 
don't  you  put  up  your  old  counterpoise  con- 
traption over  the  trees  and  over  the  house." 

So  1  did. 

I  don't  know  by  experience  what  a  theoreti- 
cally good  counterpoise  could  do  to  my  set,  but 
anyway,  the  one  I  put  up  over  trees  'n  every- 
thing, boosted  my  antenna  current  right  off  the 
bat  to  3!  amperes  on  straight  C.  W.,  on  275 
meters;  and  then  to  around  45  on  342  meters 
after  1  had  made  a  few  thousand  more 
adjustments. 

Now  I  connected  in  the  magnetic  modulator 
which  brought  the  current  down  to  around 
3  amperes  after  re-tuning.  The  phonograph 
was  then  started  and  my  friend  about  1,000 
feet  away  was  asked  how  it  sounded.  He  said 
it  didn't  sound  at  all,  it  buzzed.  I  asked  him 
if  it  buzzed  like  a  saw-mill  and  he  said  no  .  .  . 
it  buzzed  like  about  ten  saw-mills. 


Set-Backs  and  Come-Backs  at  6KW 


37i 


I  then  wrote  down  in  my  log,  "  Communi- 
cation just  received  from  one  thousand  feet 
away  saying  we  are  coming  in  loud— 'Can  hear 
you  all  over  the  house.'" 

1  was  surely  "radiating"  now. 

"Can  you  hear  the  music?"  I  asked  him. 

"  Yes,  maybe,"  he  came  back,  "  if  you  could 
shut  down  the  saw  mills." 

Some  people  are  so  unappreciative. 

Well,  naturally,  I  decided  the  filter  circuit 
must  be  leaking,  so  1  added  more  condensers 
and  filter  coils,  took  some  out  here  and  put 
them  there  and  after  trying  many  combinations 
I  finally  found  I  could  eliminate  most  of  the 
60-cycle  hum  by  proper  adjustment  of  the 
filament-tap  return  on  the  tank  inductance. 
I  was  then  using  circuit  No.  5  of  the  R.  C.  A. 
catalogue. 

My  first  report  was  from  a  sugar  mill  about 
80  miles  from  Tuinucu,  using  342  meters.  My 
friend,  Mr.  Leonard  Fox,  the  manager  there, 
and  a  fellow  radio  fan,  said  he  heard  me  fairly 
loud  with  quite  a  bit  of  hum. 

With  this  arrangement  I  experimented  and 
transmitted  for  about  two  months,  finally 
greatly  improving  the  modulation  by  bridging 
a  variable  condenser  around  the  secondary 
of  the  magnetic  modulator  with  a  value  of 


about  .003  mfd.  This,  also,  cut  out  a  lot  of  the 
remaning6o-cycle  hum.  1  was  then  being  heard 
all  over  Cuba,  with  maximum  distances  in 
Cuba  from  Tuinucu  being  around  300  miles. 

Friend  Pierri  of  the  R.  C.  A.  then  suggested 
that  I  try  the  same  set  using  one  50-watt  tube 
as  oscillator  and  one  50-watt  tube  as  modulator, 
adding  the  necessary  choke  coils  and  making  a 
slight  change  in  the  wiring  circuit.  This  gave 
me  2^  to  3  amperes  in  the  antenna  on  310 
meters,  and  letters  began  to  come  in  from 
points  in  Florida,  U.  S.  A.  saying  they  were 
hearing  me  quite  clearly.  After  that,  I  added 
a  5-watt  tube  as  speech  amplifier  in  front  of  the 
modulator  tube  and  all  during  December  of 
1922  and  January,  February,  and  to  March  1, 
1923,  my  50-watter,  so  arranged,  was  heard 
quite  consistently  all  through  the  Southeastern 
states  with  a  goodly  number  of  reports  from 
Pennsylvania,  New  Jersey,  New  York,  and 
Porto  Rico. 

While  I  was  still  fussing  around  trying  to  get 
rid  of  my  60-cycle  hum,  an  enthusiastic  (?) 
listener  wrote  me  in  Spanish  asking  if  1  would 
kindly  do  my  transmitting  during  the  "madru- 
gada"  (midnight  to  morning)  as  he  wanted  to 
listen  to  KDKA  and  my  battery  of  saw  mills 
"distracted"  his  attention. 


THIS  IS  WHERE  THE  "jUICE"  ORIGINATES  FOR  6KW 
As  the  power  plant  of  an  amateur's  broadcasting  station,  this  would  indeed  be  imposing,  but  it  is  first 
and  foremost  the  power  plant  of  the  Tuinucu  Sugar  Company,  of  which  Mr.  Jones  is  chief  electrical  engineer 


372 


Radio  Broadcast 


These  Spanish  people  are  very  polite. 

Caramba,  pense  yo,  mi  idea  original  era 
ieneo    un   trasmisora   de   100  vatios.  Voyll 

So  1  squeezed  my  pocket-book  again  and 
bought  some  more  tubes,  coils,  condensers- 
and  a  iooo-volt  D.  C.  generator.  No  more 
6o-cycIe  hum  for  me,  and  with  D.  C.  you  don't 
have  any  hum  to  filter  out,  oh,  of  course  not! 

More  waiting. 

I  swear  to  goodness,  from  the  time  it  takes  to 
get  this  kind  of  apparatus  down  here,  one 
would  think  that  every  one  of  a  million  people 
in  the  U.  S.  A.  were  building 
transmitters  also. 

Considerable  difficulty  was  en- 
countered at  first  in  eliminating  the 
hum  caused  by  the  commutator 
ripple  of  the  D.  C.  generator,  but 
this  was  finally  almost  perfectly 
accomplished  by  using  about  9 
mfds  across  the  D.  C.  and  some 
additional  filter  coils  as  shown  in 
the  circuit  (page  374). 

The  antenna  current  on  31  5  meters  with  900 
volts  on  the  plates  is  3!  amperes,  and  this  in- 
creases to  j\\  during  speech  or  music.  1  now 
transmit  concerts  on  31 5  meters  and  my  broad- 
casting license,  under  Cuban  laws,  allows  me  to 
use  from  300  to  360.  The  call  letters  of  this 
license  are  6KW.  It  is  a  Cuban  class  "C" 
station. 

I  am  also  a  member  of  the  American  Radio 
Relay  League  and  this  summer  1  hope  to  open 
up  traffic  between  Porto  Rico  and  Cuba  and 
amateurs  in  the  U.  S.  A.  1  have  also  a  class 
"B"  license  which  down  here  is  for  amateur 
phone  and  C.  W.  telegraph.  No  spark  trans- 
mitters are  to  be  allowed  in  Cuba.  Move 
along,  you  rock-crusher  operators  in  the  States 
and  don't  let  Cuba  lead  too  long.  Don't  try 
to  sell  it  to  some  newcomer,  just  bury  it  and 
stand  the  loss  and  your  new  C.  W.  set  will 
more  than  pay  you.  I  know — 1  used  to  have 
a  spark  set  way  back  in  1907.  My  class  "  B" 
license  call  number  is  6XJ,  and  1  shall  use  I.  C. 
W.  on  275  meters.  Next  winter  1  shall  use 
straight  C.  W.  for  work  with  England  and 
France. 

Ye  Gods,  when  I  think  back.  .  .  .  With 
my  old  spark  set  of  1  K.  W.  rating,  I  used  to 
get  50  to  75  miles  when  she  was  "good"  and  I 
take  off  my  hat  to  the  boys  who  get  such  fine 
DX  work  on  only  20  watts. 

I  first  tested  out  my  new  100-watt  set  on 
March  9,  1923,  and  had  previously  advised  a 


friend,  Mr.  Donald  Hutchinson  of  North 
Tarrytown,  N.  Y.  to  be  listening  for  me.  He 
cabled  next  morning  that  he  heard  me  so  loud 
and  clear  that  he  couldn't  comfortably  use  the 
headphones. 

The  modulation  of  Station  6KW  has  been 
reported  good  from  Dakota  to  St.  Johns,  New- 
foundland, signals  clear,  wave  steady,  and  good 
volume.  Literally,  thousands  of  letters  have  been 
received  from  enthusiastic  listeners,  and  1  do 
think  that  for  100  watts  it  gets  out  very  well. 
1  have  many  letters  from  Canada.  Hundreds 
up  there  have  reported  6 KW  louder 
and  clearer  than  some  of  theirgood- 
sized  local  stations.  1  don't  pretend 
to  explain  this.  Perhaps  someone 
will  come  along  and  explain  away 
the  mystery.  6KW  has  been  heard 
many  times  with  consistent  volume 
and  clearness  in  every  state  east 
of  the  Rocky  Mountains;  in  Can- 
ada, in  every  province  from 
Saskatchewan  to  Newfoundland. 
St.  John's  is  2,500  miles  from  Tuinucu.  Re- 
ports have  come  from  all  over  Cuba,  of  course, 
Porto  Rico,  Hayti,  Jamaica,  Mexico,  Central 
America,  and  throughout  the  Panama  Canal 
Zone.  I  don't  believe  they. have  any  receiving 
sets  in  the  northern  part  of  South  America,  for 
from  there  to  Tuinucu  it  is  only  900  miles,  and 
I  have  no  report  as  yet  from  South  America. 

The  koo'ing  of  a  cuckoo  bird  is  reproduced 
between  numbers  during  concerts  and  the 
slogan  which  I  adopted  is  "  If  you  hear  the 
'koo'  of  the  cuckoo,  you  are  in  tune  with 
Tuinucu,  Cuba." 

A  perusal  of  the  letters  received  by  a  broad- 
casting station  reveals  some  curious  phases  of 
psychology.  On  one  night  when  I  transmitted 
nothing  but  phonograph  records,  I  only  an- 
nounced "phonograph  record"  after  one  par- 
ticular selection.  A  man  wrote  in  saying  that 
he  liked  all  the  orchestra  selections,  but  that  he 
did  not  like  "the  phonograph  record"  and 
never  did  like  phonograph  records  over  the 
radio.  My  experience  is  that  eight  out  of  ten 
people  can't  tell  the  difference,  if  the  trans- 
mitter is  working  well,  the  record  is  new,  and 
the  microphone  properly  placed. 

Another  man  wrote  in  from  the  frozen  north 
asking  if  I  operated  the  transmitter  in  pa- 
jamas! No  one  suffers  with  the  heat  in  Cuba. 
Sunstroke  is  practically  unknown.  One  is 
usually  comfortable  at  night  with  a  light 
blanket  on  the  bed. 


Set-Baeks  and  Gome-Backs  at  6KW 


373 


THE  STUDIO  IN  MR.  JONES  S  HOME 


Many  listeners-in  pleaded  to  have  me  open 
a  bottle  of  champagne  in  front  of  the  micro- 
phone and  let  them  just  hear  the  "pop." 

We  have  winds  here  in  Cuba  that  play  havoc 
at  times.  You  may  look  at  your  antenna  in 
the  morning  and  think  what  a  beauty  it  is;  and 
the  next  night  it's  on  the  ground,  maybe,  masts 
and  all.  Then  we  just  heave  to,  and  put  it  up 
again  and  "nothing  to  do  till  to-morrow." 

And  lightning  during  the  summer  months, 
WOW!  Several  times  1  have  seen  all  the 
incandescent  street  lamps  light  up  with  a 
heavily  charged  atmosphere  here  during  storms. 
You  can  open  your  antenna  grounding  switch 
j  inch  many  times  with  a  clear  sky  and  a 
continuous  stream  of  j-inch  sparks  will  flow 
from  antenna  to  ground.  Once  my  antenna 
was  found  all  tangled  up  in  a  tree  a  quarter  of 
a  mile  from  its  home. 

The  Cuban  government  first  assigned  me 
5KW  and  after  I  had  been  announcing  this 
for  about  a  week  they  changed  it  to  6KW. 
The  numbers  refer  to  the  Provinces.  No.  1  — 
Pinar  del  Rio;  Nos.  2,  3,  and  4,  Havana;  No. 
5,  Matanzas;  No.  6,  Santa  Clara;  No.  7, 
Camaguey;  and  No.  8,  Oriente. 

I  transmitted  for  several  months  before  I 
had  call  letters,  but  I  had  a  special  permit,  so, 
while  I  was  OK  legally,  it  caused  many  dis- 


cussions in  the  States  as  to  why  the  station  of 
"Frank  H.  Jones"  never  signed  off  with  call 
letters. 

Naturally  musical  talent  is  hard  to  obtain 
here  in  the  "woods"  as  one  might  say,  but  we 
very  frequently  have  orchestras  here  from 
nearby  towns  for  dances  in  the  " Sociedad" , 
"Escuela",  or  the  manager's  house  on  the 
plantation.  1  have  put  up  private  metallic 
circuits  to  all  these  places  running  to  my 
house  and  also  from  our  "park"  and  all  the 
concerts  and  dances  and  "doings"  in  these 
places  I  can  transmit. 

The  Cuban  Government  also  authorized 
6KW  to  broadcast  officially  the  weather  report 
which  is  telegraphed  to  me  daily  from  the 
National  Observatory.  I  pick  up  also  in  the 
early  evening,  many  bits  of  news  by  radio  from 
the  States  and  sometimes  1  broadcast  these. 

Tuinucu  (pronounced  Too-e-nu-koo)  has 
been  spelled  no  fewer  than  hundreds  of  differ- 
ent ways,  some  listeners  even  addressing  their 
cards  "  Stoni-cove,"  "Cuni-kuk,"  "Cookuti- 
cuk, "  "Punicu,"  "Sonnicu"  and  "Boomicu." 
My  wife  gets  the  most  fun  reading  these  ad- 
dresses. Tuinucu  is  the  plantation  town  and 
home  of  the  Tuinucu  Sugar  Company  cane- 
sugar  mill.  It  is  located  almost  exactly  in  the 
centre  of  the  island  of  Cuba  about  eight  miles 


374 


Radio  Broadcast 


MILLIAMNIETER  FOR 
OSCILLATOR  PLATES  0-500 


MILLIAMMETER  FOR 
MODULATOR  PLATES  O-50O 


MILLIAMMETER  FOR  PLATE 
VOICE  AMPLIFIER  0-500 


M.G.  1000  V.  600  MILLIAMPERES 

DIAGRAM  OF  THE  TRANSMITTER  CIRCUIT  USED  AT  6KW 


northeast  of  Sancti  Spiritus  and  about  a  mile 
west  of  Zaza  del  Medio,  both  of  these  latter 
towns  usually  being  found  on  maps,  although 
Tuinucu  may  not  be  shown.  Tuinucu  is  200 
miles  by  air  line  east  of  Havana. 

Some  operating  data  on  the  transmitter 
when  using  the  315-meter  wave  may  be  of 
interest.  The  current  in  the  tank  circuit  may 
be  around  8  amperes  when  4J  is  being  radiated. 
Under  these  conditions,  the  oscillator  tubes 
show  about  280  to  350  milliamperes  in  the  plate 
circuit ;  the  modulator  tubes  100  to  400  milliam- 
peres on  plates,  and  amplifier  tube  plate  from 
25  to  125  milliamperes;  these  currents  applying 
when  the  plate  voltage  is  900  volts. 

In  eliminating  parasitic  sounds  in  a  trans- 
mitter, one  has  to  be  as  careful  in  the  wiring  as 
in  a  good  receiver.  All  the  leads  liable  to 
produce  feed-back  effects  are  run  in  lead- 
covered  wire  with  the  casings  grounded.  1 
first  had  the  i^-henry  choke  near  the  modu- 
lating and  oscillating  tubes,  but  its  strong 
flux  made  it  necessary  to  place  it  farther  away. 
I  found  that  it  is  also  well  to  mount  the  tubes 
on  several  thicknesses  of  felt.  All  mechanical 
vibrations  have  to  be  carefully  guarded  against. 
1  first  had  my  motor  generator  in  the  same  room 
as  the  transmitter,  but  even  its  slight  vibration 
was  picked  up  by  the  amplifier  tube  and 
tremendously  amplified.  I  then  mounted  the 
motor  generator  in  another  room  about  30 
feet  from  the  operating  room  and  on  a  concrete 
base  extending  from  the  ground  up  through 
the  floor  of  the  house  but  not  touching  the  floor. 


Just  a  word  about  my  receiving  apparatus. 
1  have  built  and  tried  out  almost  every  circuit 
1  ever  saw  described,  but  for  good,  reliable 
work,  both  near  and  DX,  I  use  either  my  G.  E. 
Company  single-circuit  or  my  Westinghouse 
R.C.  Either  of  these  is  generally  sufficiently 
selective  with  a  fairly  short  antenna  and  plenty 
of  tickler  coupling  and  low  filament  voltage. 

I  began  playing  the  game  of  "  Radio  Golf"  a 
couple  of  years  ago,  and  after  I  had  made  a  score 
of  more  than  100,000  miles  1  quit  keeping  track. 
My  real  object  in  starting  the  game  was  to  get 
people  really  to  know  how  to  use  their  de- 
tectors. My  watchword  was  always:  "What 
I  can't  hear  on  detector  alone  can't  be  heard  on 
audio  amplification." 

I  built  a  radio-frequency  set  with  3  stages 
of  R.  F.  and  detector  (page  370),  this  set  being 
arranged  with  various  combinations  to  use 
antenna  or  18"  loop  alone  or  in  combination 
with  the  well-known  three-circuit  regenerative 
tuner,  using  vario-coupler,  grid  variometer 
and  plate  variometer.  On  the  loop,  I  have 
heard  everything  1  have  been  able  to  pick  up 
on  the  antenna  with  the  detector  alone  in  the 
regenerative  set.  Generally  speaking,  how- 
ever, I  prefer  to  use  my  single-circuit  sets. 
With  them  I  can  usually  pick  up  a  station  and 
tune  it  in  (if  it's  possible)  in  a  few  seconds, 
while  to  pick  up  and  tune  in  well  a  station 
1,000  miles  away  on  the  R.  F.  set,  requires  a 
lot  of  time  and  more  patience.  Of  course,  in 
the  case  of  a  real,  "dyed  in  the  wool"  radio 
amateur,  his  middle  name  is  patience. 


The  Thoriated  Tungsten  Filament 


Characteristics  of  the  New  X-L  Filament,  Used  in  the  UV-201-A  and 
UV-199  Tubes.    Comparisons  with  the  Older  Pure  Tungsten  Type 

By  W.  C.  WHITE 

General  Electric  Company 

The  papers  of  the  Radio  Club  of  America  are  being  published  exclusively  in  Radio  Broadcast.  Mr. 
White's  discussion  in  this  number  is  the  second  of  the  Club's  articles  to  appear.  The  first,  "  Eighteen  Years 
of  Amateur  Radio,"  by  George  E.  Burghard,  was  published  last  month. — The  Editor. 


TN  THE  design,  manufacture,  and  use  of 
high-vacuum  receiving  tubes,  the  electron 

I  source,  in  most  cases,  has  always  been  the 

1  chief  problem. 

By  far  the  greatest  amount  of  scientific 
work  on  vacuum  tubes  and  also  a  considerable 
part  of  the  manufacturing  development  has 
been  devoted  to  this  question  of  the  production 
of  electrons. 

Until  quite  recently,  the  pure  tungsten  fila- 
ment and  the  coated  filament  were  the  only  two 
types  of  electron-emitting  sources  in  extended 
use  in  receiving  tubes.  Although  each  of  these 
sources  met  the  requirements  of  practical  use, 
it  has  been  found  possible  to  reduce  the  filament 
energy  and  secure  other  characteristics  equal 
or  better  than  that  formerly  obtained. 

The  important  desirable  features  which  the 
ideal  electron-emitting  filament  for  a  high- 
vacuum  receiving  tube  should  have,  some  of 
which  are  self-evident,  can  be  listed  as  follows: 

(1)  Long  operating  life. 

(2)  Low  filament  energy  to  supply  the  necessary 
electron  emission. 

(3)  Uniformity  of  electron  emission  during  life. 

(4)  Uniformity  of  electron  emission  among  differ- 
ent tubes  of  the  same  type. 

(5)  Quietness  of  operation. 

(6)  "Electrical  robustness"  of  the  filament. 

Another  most  desirable  feature,  if  not  the 
most  important,  but  which  is  not  so  self-evident, 
is  the  necessity  for  low  electron  emission  per 
unit  of  length  or,  expressed  in  another  way,  the 
greatest  length  possible  within  reason  for  a 
given  amount  of  electron  emission  and  filament 
energy.  These  features  of  long  filament  length 
combined  with  long  life  and  low  filament 
energy  were  always  the  difficult  problems  in 
tungsten  filament  design  for  receiving  tubes. 

The  new  X-L  tungsten  filament  meets  these 


many,  and  it  would  almost  seem,  divergent 
requirements  in  a  most  admirable  way,  and 
although,  of  course,  it  is  probably  not  the  final 
development  in  electron-emitting  sources,  still 
it  is  such  a  big  advance,  particularly  over  the 
old  type  of  pure  tungsten  filament,  that  it  meets 
to  a  considerable  extent  the  ideal  requirements. 

The  outstanding  features  of  this  new  X-L 
tungsten  filament  considered  from  the  view- 
point of  the  desirable  features  of  the  ideal  and 
in  comparison  with  the  old  pure  tungsten  fila- 
ment are  as  follows: 

(1)  For  the  same  life,  the  X-L  filament  can  have 
several  times  the  electron  emission,  and  only  a 
fraction  of  the  same  amount  of  energy  is  re- 
quired for  excitation.  This  is  best  brought  out 
by  a  comparison  between  the  old  UV-201  and 
the  new  UV-201-A  tubes,  the  latter  tube  utilizing 
this  new  X-L  tungsten  filament.  This  compari- 
son is  a  convenient  one  to  bring  out  these  points 
because  the  two  tubes  are  made  to  be  inter- 
changeable and  to  operate  from  the  same  fila- 
ment voltage. 


Filament 
Type        Volts    A  mperes 
UV-201  5  1 

UV-201-A       5  .25 


Watts 
5 

1.25 


Electron  Emission 
Milliamperes 

7-5 
45 


(2)  The  uniformity  of  electron  emission  from  the 
X-L  filament  is  the  same  asfrom  the  old  tungsten 
filament.  This  can  be  brought  out  by  the  fact 
that  in  the  UV-199  tube,  which  also  uses  the  X-L 
filament,  measurement  of  electron  emission  has 
been  made  on  every  tube  leaving  the  factories. 
The  minimum  allowable  limit  is  six  milliamperes. 
The  average  of  thousands  of  tubes  is  eight  milli- 
amperes, and  practically  the  highest  that  is  found 
among  the  standard  product  is  twelve  milli- 
amperes. 

(3)  Tube  noise,  a  troublesome  feature  in  the  older 
type  of  tungsten  tube,  is  practically  eliminated 
with  the  X-L  filament,  largely  because  of  the 
much  lower  operating  temperature. 


376 


Radio  Broadcast 


(4)  The  feature  of  increased  electron  emitting  length 
is  well  brought  out  by  the  following  tabulation, 
again  a  comparison  between  the  UV-201  and  the 
UV-201-A  tubes: 


Type 


Approxi- 

Approxi-   Fila-  mate  Relative 

mate       ment        Mutual  Delivered 

Life      Length  Conductance  Energy 


UY-201  1000  38  mm.  300 
UV-201-A     1000     48  mm.  475 


From  the  foregoing  tabulation  it  will  be  seen 
that  there  is  more  than  fifty  per  cent,  increase  in 
mutual  conductance  due  to  the  longer 
filament  which  allows  also  the  use  of 
larger  plate  areas.  The  figures  under 
the  column  "Relative  Delivered  En- 
ergy" imply  that  under  similar  con- 
ditions the  increased  mutual  conduct- 
ance allows  the  UV-201-A  tube  to  give 
about  double  the  energy  output  as  an 
amplifier.  The  figures  for  mutual  con- 
ductance given  above  refer  to  these  constants 
measured  at  rated  filament  voltage,  a  plate 
voltage  of  forty  and  a  grid  voltage  of  zero. 
Probably  this  feature  of  increased  electron  emit- 
ting area  with  the  X-L  filament  can  be  more 
clearly  brought  out  by  the  statement  that  if  an 
X-L  filament  tube  were  built  operating  at  the 
same  filament  temperature  as  the  UV-201 -A 
but  having  the  same  volts  and  amperes  as  the 
UV-201  and  the  same  life,  the  electron  emission 
from  the  X-L  filament  would  be  twenty-four 
times  as  great  and  the  length  approximately 
double  that  of  the  pure  tungsten  filament. 
(5)  The  X-L  filament  has  a  long  life.  Life  in  this 
case  is  not  terminated  by  a  burnout,  but  by  loss 
of  electron  emission.  This  drop  of  emission 
does  not  occur  continously  during  the  life  of  the 
filament,  but  quite  suddenly,  and  in  a  very 
pronounced  way  at  the  end  of  its  useful  life. 
The  relation  between  life  and  filament  voltage  is 
not  a  simple  relation,  because  operation  at 
abnormally  high  voltage  will  destroy  electron 
emission  which,  however,  can  be  renewed  by  the 
proper  procedure  in  the  hands  of  the  user.  This 
question  of  life  of  the  tube  and  the  fundamental 
causes  allowing  this  possibility  of  renewing 
electron  emission,  or  reactivation,  as  it  is 
termed,  will  be  discussed  more  fully  in  the 
following  paragraphs. 

.  The  electron  emission  from  a  given  material 
can  be  expressed  by  a  fairly  simple  formula  and 
is  determined  by  two  factors,  one  of  which  is  a 
constant  that  is  typical  of  that  material  and 
the  second  is  a  function  of  the  temperature; 
the  electron  emission  increasing  very  rapidly 
with  temperature.  In  the  case  of  a  coated 
filament,  the  constant  of  the  material  indicates 


a  high  emission,  but  the  allowable  temperature 
is  low.  In  the  case  of  the  pure  tungsten  fila- 
ment, the  constant  of  the  material  indicates 
a  relatively  low  electron  emission  at  a  given 
temperature,  but  there  is  the  practicability  of 
operating  at  relatively  high  temperatures. 

It  has  been  found  that  in  general  in  the  case 
of  suitable  electron  emitting  substance  the 
more  stable  and  homogeneous  the  material 
the  lower  the  electron  emission  and,  conversely, 
the  lower  the  temperature  at  which  the  ma- 
terial evaporates  or  disintegrates  the  higher  the 
electron  emission.  Another  factor 
found  experimentally  was  that  in  most 
cases  the  more  active  the  material,  that 
is,  the  greater  the  electron  emission  at 
low  temperature,  the  more  subject  the 
material  was  to  loss  of  electron  emission 
from  contamination  and  insufficient 
vacuum;  certain  gases  or  vapors  in  par- 
ticular being  very  fatal  to  this  electron  emission. 
The  problem,  therefore,  was  one  of  finding 
a  compromise  between  these  divergent  factors. 

The  X-L  filament  is  a  tungsten  filament  in 
which  there  is  a  small  percentage,  considerably 
under  five  per  cent,  of  a  material  that  has  high 
electron  activity.  This  active  material  in  the 
case  of  the  X-L  filament  as  at  present  used  is 
thorium  and  a  chemical  compound  of  this 
thorium  is  mixed  with  the  tungsten  early  in  the 
stage  of  the  manufacture  of  the  metal  from 
which  the  filament  wire  is  drawn. 

When  the  completed  filament  containing  this 
active  material  is  operated  in  a  vacuum  at  a 
certain  high  temperature,  there  is  a  change 
from  the  chemical  compound  to  pure  thorium. 
At  another  certain  lower  temperature,  there  is 
a  constant  diffusion  of  this  thorium  toward 
the  surface  of  the  filament.  By  this  process, 
a  layer  of  these  thorium  atoms  one  atom  deep, 
(and  only  one  atom  deep)  is  formed  on  the 
surface  of  the  filament.  This  atomic  layer 
of  thorium  is  of  high  electron  emissivity  so  that 
ample  electron  emission  is  obtained  from  it  at 
temperatures  that  would  give  practically  no 
useful  electron  emission  from  a  pure  tungsten 
filament. 

Thorium  cannot  remain  indefinitely,  how- 
ever, on  the  surface  of  a  hot  filament,  because 
in  comparison  with  tungsten,  it  has  a  higher 
rate  of  evaporation,  this  rate,  of  course,  increas- 
ing rapidly  with  the  temperature.  At  the 
temperature  at  which  the  X-L  filament  is 
operated,  this  evaporation  is  relatively  slow, 
but  is  quite  appreciable.    The  instant  that  an 


The  Thoriated  Tungsten  Filament 


377 


atom  of  thorium  evaporates 
from  the  surface  there  is  a 
movement  of  atoms  inside 
the  body  of  the  material 
which  places  another  atom 
in  the  surface  layer  in  the 
position  occupied  by  the 
former  atom  after  which 
movement  there  is  again 
equilibrium  of  thorium  in- 
side the  filament. 

A  rough  analogy  to  the 
actions  just  described  is  the 
case  of  a  jar  of  liquid  which 
is  capable  of  forming  bub- 
bles. The  production  of 
pure  thorium  can  be  likened 
to  the  formation  of  air 
bubbles  at  the  bottom  of 
the  jar  and  the  diffusion  of 
these  thorium  atoms  to  the 
surface  of  the  filament  can 
be  likened  to  these  air 
bubbles  rising  to  the  surface  of  the  liquid.  As 
in  the  case  of  the  thorium  atoms,  these  small 
air  bubbles  will  distribute  themselves  so  that 
the  entire  surface  is  covered  with  bubbles  one 
layer  deep.  If  more  bubbles  are  then  formed 
at  the  bottom  of  the  jar,  they  will  rise  until 
they  strike  the  under  surface  of  the  surface 
layer  of  bubbles  and  there  will  remain  station- 
ary and  it  is  possible  to  thus  form  a  thick  mass 
of  the  bubbles,  all  stationary.  The  evapor- 
ation of  the  thorium  from  the  surface  of  the 
filament  may  be  likened  to  the  evaporation  of 
the  film  of  some  of  the  bubbles  in  the  surface 
layer  which  causes  these  bubbles  to  burst 
and  immediately  other  bubbles  from  beneath 
rise  to  the  surface  taking  the  place  of  the 
bubbles  just  destroyed. 

In  the  case  of  the  filament,  the  higher  the 
temperature  the  greater  the  evaporation  of  the 
thorium  from  the  surface  which  would  corres- 
pond in  this  analogy  to  the  bubbles  in  the 
surface  layer  of  the  liquid  bursting  at  more 
frequent  intervals. 

The  bubble  analogy  is  in  one  respect  not  a 
good  one,  and  this  point  is  that  the  volume 
occupied  by  the  thorium  atoms  is  only  a  very 
small  portion  of  the  total  volume  of  the  ma- 
terial near  the  surface  of  the  filament,  whereas, 
in  the  case  of  the  bubbles  in  the  jar  of  liquid 
the  volume  of  these  bubbles  under  the  surface 
is  much  greater  than  the  volume  occupied  by 
the  liquid.    Therefore,  in  the  bubble  analogy 


FIG.  i 

The  UV-199  dry-cell  tube.    It  uses  the  new  thoriated  tungsten  filament 


the  layer  of  atoms  one  atom  deep  is  not  clearly 
portrayed  because  the  bubbles  underneath 
crowd  toward  the  surface  displacing  practically 
all  the  liquid. 

The  reactions  inside  of  the  X-L  filament 
when  operating  at  its  normal  temperature  are 
such  that  the  production  of  thorium  in  the 
interior  and  the  rate  of  its  diffusion  to  the 
surface  are  proportioned  so  that  at  normal 
rated  temperature  they  amply  compensate  for 
the  loss  of  thorium  atoms  by  evaporation. 

There  is  one  effect,  however,  which  tends 
to  prevent  the  practical  utilization  of  the  pro- 
cess in  the  simple  form  here  outlined. 

In  an  earlier  paragraph  it  was  stated  that  one 
of  the  disadvantages  of  an  active  electron 
emitting  material  was  its  liability  to  contami- 
nation. This  contamination  consists  of  the 
chemical  combination  of  some  gaseous  or  vapor 
impurity  in  the  vacuum  with  the  thorium  at 
the  surface  of  the  filament,  which  is  emitting 
the  electrons.  The  X-L  filament  would  be 
very  sensitive  to  such  contamination  and 
this  chemical  compound  formed  at  the  sur- 
face by  this  contamination  would  not  emit 
any  electrons  and  would  require  an  exceedingly 
high  temperature,  up  to  near  the  melting 
point  of  the  tungsten,  to  remove  it  and 
leave  free  the  surface  area  for  the  pure  active 
material.  Therefore,  in  the  case  of  the  X-L 
filament,  unless  some  precautionary  measures 
were   taken,    the   electron    emission  would 


378 


Radio  Broadcast 


last  only  a  few  seconds  or  a  few  minutes 
during  which  time  the  active  surface  would 
become  so  contaminated  that  the  emission 
would  drop  to  practically  zero. 

This  problem  of  keeping  the  active  surface 
of  the  filament  "clean"  was  solved  by  first 
finding  out  what  the  contaminating  agents 
were  and  then  by  placing  inside  the  bulb  cer- 
tain substances  that  would  have  a  more  active 
chemical  combination  with  these  contaminating 
agents  than  the  thorium  surface  on  the  fila- 
ment. The  presence  of  such  substances  pre- 
vents contamination  of  the  filament 
by  previously  combining  with  the  con- 
taminating agents.  It  does  not  in  any 
way  increase  the  electron  emission  from 
the  filament  directly,  but  simply  pro- 
tects the  thorium  film  so  that  the  full 
electron  emission  characteristic,  as 
would  be  obtained  in  practically  a 
perfect  vacuum,  is  more  conveniently  realized. 

Keeping  in  mind  the  phenomena  just 
described,  the  various  characteristics  of  the 
X-L  filament  as  an  electron  emitting  source 
are  explainable. 

For  instance,  if  the  filament  is  operated 
at  an  abnormally  high  temperature,  the 
electron  emission  at  first  will  be  very  large, 
but  the  higher  this  abnormal  temperature  the 
quicker  will  this  high  electron  emission  fall  off 
until  it  is  below  even  normal  value.  This 
rapid  falling  of  electron  emission  is  due  to  the 
fact  that  the  rate  of  evaporation  of  thorium 
from  the  surface  is  more  rapid  than  the  dif- 
fusion to  the  surface  and,  therefore,  the  surface 
of  the  filament  is  no  longer  covered  v/ith  the 
active  thorium,  but  only  with  pure  tungsten, 
the  electron  emission  from  which  at  a  given 
temperature  is  far  below  that  from  thorium. 
If  then  the  filament  is  operated  at  normal 
temperature  for  a  short  period  of  time,  the 
evaporation  of  thorium  is  reduced  to  normal 
and  the  diffusion  from  the  interior  rebuilds  the 
electron  emitting  layer  at  the  surface.  As  the 
surface  of  the  filament  becomes  more  and  more 
completely  covered  with  thorium,  the  electron 
emission  rises  until,  when  it  has  become  fully 
covered,  it  returns  to  normal. 

This  brings  out  the  point  that  there  is  an. 
optimum  temperature  for  operation  of  the 
X-L  filament,  or  more  properly  speaking,  a 
restricted  range  of  temperature  for  satisfactory 
operation.  If  the  temperature  is  maintained 
above  this  range,  the  electron  emission  sooner 
or  later  falls  off  as  explained,  but  there  is  no 


permanent  injury  to  the  filament  unless  this 
misuse  is  continued,  and  operation  again  at 
normal  value  soon  brings  back  normal  electron 
emission.  If  the  operation  is  below  this  use- 
ful temperature  range,  the  electron  emitting 
efficiency  is  unnecessarily  low. 

Under  rare  operating  conditions,  the  supply 
of  thorium  in  the  interior  of  the  filament  might 
become  deficient,  which  would  reduce  the 
supply  of  thorium  arriving  at  the  surface  and 
fail  to  keep  a  complete  layer  at  the  filament 
surface.  Under  these  circumstances,  there  is 
usually  still  a  supply  of  the  thorium 
compound  present  which  was  originally 
put  into  the  filament  metal  and  by 
operation  of  the  filament  at  approxim- 
ately three  times  normal  voltage 
for  a  fraction  of  a  minute  there 
will  be  a  new  production  of  pure 
thorium.  Then,  after  this  new  pro- 
duction of  thorium  has  occurred,  operation 
of  the  filament  at  normal  temperature  for  a 
reasonable  period  of  time  will  cause  this  new 
thorium  to  be  diffused  to  the  surface  and  a 
new  complete  active  electron  emitting  layer  will 
be  formed. 

Also,  under  abnormal  conditions,  such  as 
overload  of  the  plate,  the  contaminating  agents 
may  be  so  plentiful  inside  the  bulb  that  the 
substances  placed  inside  to  absorb  these  con- 
taminating vapors  and  gases  may  not  take 
them  up  rapidly  enough  and  so  allow  a  con- 
tamination of  the  filament.  Again,  the  cure 
for  this  condition  is  to  operate  the  filament  for 
a  few  seconds  at  about  three  times  normal 
voltage  which  decomposes  this  contaminated 
thorium  from  the  surface  of  the  filament  and 
then  by  operation  at  normal  temperature  for  a 
reasonable  time  the  normal  thorium  layer  and 
normal  electron  emission  are  regained. 

The  length  of  time  that  the  filament  must  be 
operated  at  normal  temperature  under  these 
different  conditions  described  in  order  to  regain 
normal  emission  varies  widely,  depending  upon 
whether  or  not  the  thorium  just  below  the 
surface  has  been  removed.  If  the  thorium  has 
been  removed  a  considerable  distance  below 
the  surface,  a  longer  time  is  required  for  it  to 
diffuse  through  this  distance  to  the  surface 
than  would  be  required  if  simply  the  surface 
layer  were  destroyed.  Therefore,  if  the  fila- 
ment has  been  operated  at  an  abnormally  high 
voltage  for  ten  to  twenty-five  hours,  it  may 
require  this  same  length  of  time  at  normal 
rated  operating  voltage  in  order  to  obtain 


The  Thoriated  Tungsten  Filament 


379 


normal  electron  emission.  It  is,  therefore, 
apparent  that  an  X-L  filament  contains  a 
certain  amount  of  stored-up  or  potential  elec- 
tron capacity  which  under  normal  conditions 
is  continuously  brought  to  the  surface  and 
utilized  in  an  efficient  manner  so  as  to  give  long 
life.  If  abnormal  conditions  occur,  this  orderly 
procedure  is  disturbed  so  as  to  cause  a  failure 
of  electron  emission.  However,  as  pointed 
out,  this  potential  source  of  electron  emission 
is  seldom  permanently  destroyed  before  the 
end  of  filament  life,  and  the  proper  procedure 
should  bring  back  normal  electron  emission. 

X-L  FILAMENT  RADIOTRON  TUBES 

THE  Model  UV-199  Radiotron  tube  utilizes 
the  X-L  filament  and  brings  out  in  a  most 
striking  manner  its  unusual  characteristics 
and,  therefore,  it  is  of  interest  to  describe 
briefly  this  tube  and  some  of  its  characteristics 
and  properties.  The  general  appearance  of 
this  Radiotron  tube  is  shown  in  Fig.  1.  The 
overall  length  of  this  tube  from  the  tip  of  the 
bulb  to  the  bottom  of  the  contact  pins  of  the 
base  is  and  its  maximum  diameter  1". 
One  of  the  first  features  noted  in  an  inspection 
of  this  tube  is  the  fact  that  the  bulb  is  opaque 
so  that  the  electrodes  are  not  visible.  This 
opaqueness  is  caused  by  the  materials  used  to 
prevent  contamination  of  the  filament  in  the 
manner  previously  described. 

The  outstanding  advantages  of  this  new  tube 
are  its  low  filament  energy  which  is  only  about 
75  per  cent,  of  that  of  any  other  tube  in  use  at 
the  present  time,  its  small  size  and  excellent 
detector  and  amplifier  characteristics. 

The  filament  is  operated  at  three  volts  and 
requires  only  sixty  milliamperes. 
*  The  tabulation  shown  below  indicates  what 
service  can  be  obtained  from  a  set  employing 
one,  -two,  three,  or  four  of  these  tubes  in  parallel 
operated  from  three  good  quality  No.  6  dry 
cells  connected  in  series.  This  tabulation 
is  based  on  the  use  of  the  tubes  two  hours  out 
of  each  twenty-four  hours. 

No.  of  tubes  in 


set 

Total  hours 

Days 

Months 

1 

387 

'93 

2 

200 

100 

3 

126 

63 

2 

4 

92 

46 

.  Pi 

u 

tit 

I  Li 

-  c 

t  W 

'hi 

{  L  L 

{ C  i 

V  f 
i  J 

ft 

"  r 

/-) 

f 

th 

fr 

u 

V  ~ 

19 

g 

'I  i 

1  . 
(  V 

//- 

€ 

P/ 

i  L 

at 

p  ( 

l  L 

on 

/ 

.  

. 

c 

Hi 
L 

«j 
-0 

Jj 

SO 

V 

c 

C 

—T 

/ 

J 

< 

/ 

y 

V 

?// 

1  V 

- 1-' 

■V. 

L 

The  extremely  low  filament  current  of  this 
UV-I9Q  tube  makes  it  possible  to  operate 
from  flashlight  cells.    Operation  from  such 


fig.  2 

The  "characteristic  curve"  of  the  UV-199 

small  size  cells  is  not  as  economical  as  from  the 
six-inch  size  of  cells.  However,  for  portable 
equipments,  this  difference  is  more  than  offset 
by  the  light  weight  and  small  size  of  these 
flashlight  cells. 

One  UV-199  tube  may  be  operated  from  a 
three  cell  flashlight  battery  one  hour  out  of 
each  day  for  a  little  over  a  month.  A  longer 
period  of  daily  operation  than  one  hour  will 
shorten  somewhat  the  total  useful  battery  life. 

For  portable  sets  containing  more  than  one 
UV-199  rube  one  three  cell  flashlight  battery 
should  be  used  for  each  tube  operated.  Opera- 
tion of  the  filaments  of  more  than  one  tube 
from  a  single  flashlight  battery  is  not  only  poor 
economy,  but  the  voltage  drop  of  the  cell  while 
in  use  under  this  heavier  current  drain  is  after 
a  short  time  so  rapid  that  operation  of  the  set 
is  unsatisfactory. 

This  size  of  unit  flashlight  cell  is  approxi- 
mately if"  in  diameter  and  2^"  long. 
Smaller  sizes  of  flashlight  cells  have  not  been 
found  satisfactory  for  use  with  these  filaments, 
because  not  only  is  the  economy  poor  but  their 
voltage  drops  so  rapidly  that  in  a  regenerative 
circuit  difficulty  is  experienced  in  satisfactorily 
holding  an  adjustment. 


380 


Radio  Broadcast 


This  use  of  flashlight  cells  combined  with  the 
small  size  of  the  tube  gives  the  possibility  of 
making  up  extremely  sensitive,  small,  and  light 
weight  portable  receiving  equipments. 

The  characteristic  curve  of  this  tube  is  shown 
in  Fig.  2,  and  is  very  similar  to  that  of  the  old 
UV-201. 

In  this  connection,  it  should  be  kept  in  mind 
that  the  UV-201 -A  tube  has  a  higher 
amplification  constant  and  lower 
impedance  than  the  UV-199  tube, 
and,  therefore,  has  a  greater  mu- 
tual conductance  so  that  it  is  in- 
herently a  better  amplifier.  This  is 
to  be  expected,  because  the  UV-201 -A 
requires  almost  seven  times  as  much 
filament  energy  and  has  bigger  elec- 
trodes. The  higher  electron  emission 
of  the  UV-201 -A  and  the  fact  that  it 
can  be  operated  at  a  higher  plate 
voltage  than  the  UV-199  combined 
with  its  better  characteristic  curve 
make  it  a  much  better  tube  to  use 
for  the  operation  of  loud  speakers 


where  an  exceedingly 


large 


volume 


FIG 

Showing 
ment  of 
on  the 


of  sound  is  required.  However,  where 
it  is  desired  to  build  a  multi-tube 
set,  the  UV-199  's>  °f  course,  super- 
ior because  a  dry  battery  can  be 
used  for  the  filaments,  whereas, 
the  same  number  of  UV-201-A 
tubes  would  make  dry  battery  opera- 
tion   rather   out  of   the  question. 

The  UV-199  tuDe  is  als0  ver>'  suitable  for 
radio-frequency  amplification,  because  the 
capacity  between  electrodes,  owing  to  their 
small  size,  is  considerably  below  that  of  any 
other  tube  available  to  the  experimenter  at  the 
present  time.  To  get  the  full  advantage  of  this 
low  capacity,  a  socket  designed  for  the  tube 
rather  than  an  adapter  to  a  standard  socket 
should  be  used.  Attention  should  also  be 
directed  to  the  set  wiring  so  as  to  keep  capacity 
effects  at  a  minimum. 

The  arrangement  of  the  contacts  on  the  base 
of  this  UV-199  tube  (Fig.  3)  is  not  the  same  as 
in  the  case  of  the  standard  bases.  This  change 
has  been  made  so.that  the  wiring  of  the  filament 
leads  as  well  as  the  plate  and  grid  leads  can  be 
more  conveniently  arranged  and  with  less 
capacity  effects  between  them  than  in  the 
former  pin  arrangement. 

One  of  the  principal  precautions  to  be  ob- 
served in  the  use  of  the  Radiotron  Model 
UV-199  is  to  be  certain  that  the  rheostat  used 


is  such  that  the  voltage  of  the  filament  source 
can  be  reduced  to  the  proper  value  of  three 
volts  for  the  filament. 

Ina  much  as  three  new  dry  cells  for  a  very 
short  time  have  a  voltage  of  4.5  volts,  this 
means  that  1.5  volts  must  at  first  be  absorbed 
by  the  filament  rheostat.  A  filament  rheostat 
of  thirty  ohms  maximum  resistance  is  recom- 
mended for  a  single  tube.  In  the  case  of  two 
tubes,  the  filaments  of  which  are  in 
parallel  and  controlled  from  a  single 
rheostat,  the  resistance  should  be 
fifteen  ohms,  and  in  the  case  of  three 
m    tubes,  ten  ohms. 

If  for  any  reason  it  is  desired  to 
operate  these  tubes  from  a  three  cell 
storage  battery  and  a  connection  for 
the  voltage  from  two  cells  cannot  be 
obtained,  the  rheostat  resistance 
should  be  at  least  sixty  ohms  for  one 
tube,  thirty  ohms  for  two  tubes,  and 
twenty  ohms  for  three  tubes. 

In  a  great  majority  of  cases,  if 
due  to  improper  operation  these  tubes 
show  low  electron  emission,  this  elec- 
tron emission  can  be  regained  by 
operation  at  normal  filament  volt- 
age for  a  period  of  time  roughly 
proportioned  to  the  time  during 
which  the  tubes  were  operated 
at  an  over- voltage.  It  is  prefer- 
able during  this  reactivation  of 
the  filament  and  often  hastens  its 
recovery  to  disconnect  the  B  battery  so  that 
there  is  no  plate  voltage  on  the  tube.  If  this 
treatment  fails  to  reactivate  the  filament,  the 
tube  filament  may  be  flashed  at  eight  to  nine 
volts  for  about  ten  seconds  and  folowed  by  a 
run  of  several  hours  at  rated  voltage.  This 
should,  in  practically  all  cases,  cause  the  return 
of  normal  electron  emission.  These  methods  of 
reactivation  will  not,  of  course,  be  successful 
if  the  tube  has  run  its  normal  life  or  has  been 
consistently  operated  at  excess  temperature  or 
misused. 

Under  normal  operating  conditions,  these 
methods  of  reactivation  are  not  necessary  dur- 
ing the  life  of  the  tube. 

Many  modern  vacuum  tube  receiving  cir- 
cuits are  of  extreme  sensitivity,  and  vibration 
often  causes  the  tube  to  introduce  into  the 
receivers  a  disturbing  sound.  This  is  termed 
microphonic  effect  of  the  tube  and  is  a  factor 
which  must  be  taken  care  of  in  multi-tube 
UV-199  circuits  in  the  same  way  as  it  has  been 


arrange- 
contacts 
UV-199 


The  Thoriated  Tungsten  Filament 


taken  care  of  in  the  use  of  other  tubes,  that  is, 
by  proper  cushioning  of  the  sockets. 

A  plate  voltage  higher  than  that  obtained 
from  four  standard  block  cells  should  not  be 
used  on  this  tube,  as  it  reduces  seriously  the 
factor  of  safety  against  overload  and  will 
shorten  the  life.  With  eighty  volts  on  the  plate 
a  negative  bias  of  three  to  4.5  volts  should  be 
used  on  the  grid.  This  is  conveniently  ob- 
tained by  two  or  three  small  flashlight  cells. 

It  is  an  interesting  fact  that  with  a  plate 
voltage  as  obtained  from  four  block  cells  and 
with  the  proper  negative  bias,  the  plate  current 
is  approximately  2.5  milliamperes  which  at 
eighty  volts  gives  a  dissipation  of  energy  on 
the  plate  of  approximately  .2  watt.  As  the 
normal  filament  energy  is  only  .18  watt,  this 
fact  that  the  plate  energy  is  more  than  the 
filament  energy  is  rather  a  striking  example  of 
the  great  improvement  that  has  been  made  in 
these  tubes  in  regard  to  filament  operation  and 
electron  emitting  efficiency. 

A  fairly  comprehensive  examination  of  tubes 
that  have  become  inoperative  due  to  actual 
filament  burnout  has  disclosed  the  fact  that  a 
very  large  majority  of  these  tubes  were  burned 
out  by  the  filament  becoming  connected  across 
the  plate  battery.  It  is  a  common  custom, 
but  dangerous  to  the  tubes,  to  make  changes  in 
the  wiring  or  connections  of  the  set  while  it  is 
in  operation  or  while  the  tubes  are  in  the 
sockets  and  the  B  battery  in  circuit.  A  mis- 
taken connection  which  puts  the  filament  of  a 
UV-199  or  UV-201-A  tube  across  a  B  battery 


of  forty  volts  or  more  that  is  in  good  condition 
usually  destroys  the  filament  so  quickly  that 
a  flash  is  not  noticeable  unless  the  tube  is 
directly  in  the  line  of  vision. 

In  view  of  these  facts,  it  is  particularly  to  be 
urged  that  wherever  possible  tubes  be  removed 
from  their  sockets  or  the  B  batten1  discon- 
nected while  experimenting  with  the  circuit 
arrangement.  An  even  preferable  arrange- 
ment and  one  which  allows  the  convenience  of 
trying  various  arrangements  without  the  pre- 
ceding precaution  is  to  insert  in  one  lead  of  the 
B  battery  at  one  batten'  terminal  a  ten-watt. 
1 10- volt  Mazda  lamp.  The  cold  resistance  of 
such  a  lamp  is  so  low  that  in  the  great  majority 
of  circuits  there  will  be  no  ill  effects,  but  such  a 
lamp  has  the  valuable  characteristic  of  increas- 
ing its  resistance  so  that  at  operating  tempera- 
tures it  is  ten  or  twelve  times  as  high  as  when 
cold.  A  ten-watt  lamp  used  in  such  a  manner 
even  with  a  plate  voltage  of  eighty  or  more  will 
limit  the  current  to  less  than  100  milliamperes 
which  can  do  absolutely  no  harm  to  even  such 
a  small  filament  as  that  used  in  the  UV-199. 
A  lamp  used  in  this  manner  also  is  convenient 
in  that  it  shows  up,  by  the  filament  becoming 
incandescent,  a  B  battery  short  circuit  or 
leakage  that  might  otherwise  go  unnoticed 
and  very  quickly  run  down  this  battery. 

The  X-L  tungsten  filament  is  not  only  use- 
ful in  receiving  tubes,  but  is  alike  applicable 
to  the  smaller  sizes  of  transmitting  tubes, 
resulting  in  a  much  lower  requirement  of  fila- 
ment energy. 


10,000  Miles  of  Radio  Lectures  in 

China 

By  C.  H.  ROBERTSON 

Science  Lecturer,  Educational  Dept.,  National  Committee  Y.  M.  C.  A.  of  China 


Back  in  1902,  Professor  Robertson  was  asked  to  give  up  his  work  on  the  Engineering  Faculty  at  Purdue 
University  and  go  to  China  to  carry  on,  under  the  auspices  of  the  Y.  M.  C.  A.,  the  work  he  had  been  doing 
in  the  United  States.  Except  for  the  war  period,  when  he  was  on  a  special  mission  in  Russia  and  Siberia, 
Professor  Robertson  has  spent  most  of  the  intervening  years  in  China.  Concerning  the  purpose  and  results 
of  these  years  of  work  in  the  Orient,  he  said,  in  1920:  "  I  have  been  back  on  the  field  but  four  months  after 
returning  from  furlough,  and  perhaps  the  most  encouraging  thing  has  been  the  constantly  increasing  in- 
dustrial development  in  mining  and  manufacturing,  in  all  this,  the  Association  (Y.  M.  C.  A.)  has  been 
a  constantly  increasing  factor  in  helping  the  people  to  assert  themselves,  in  pointing  out  and  studying  new  and 
difficult  problems  that  the  rising  industrial  life  presents,  and  has  been  particularly  helpful  in  encouraging 
right  educational  ideals  and  methods.  In  the  face  of  these  and  other  things,  there  should  be  no  retrench- 
ment, we  should  advance." 

Professor  Robertson's  account  of  his  radio  lectures  in  China  is  especially  interesting  as  a  revelation  both 
of  the  widespread  interest  in  modern  scientific  progress  evidenced  by  Chinese  of  intelligence,  and  of  the 
rapidity  with  which  knowledge  of  radio  communication  is  being  assimilated  and  turned  to  practical  account. 
— The  Editor. 


iHE  radio  telephone  as  a  lecture  sub- 
ject has  gripped  China  more  power- 
full}'  than  any  other  subject  in  the 
twenty  years  of  lec- 
ture experience  of  the 
writer  in  the  "  Middle  Flowery 
Peoples  Government  Coun- 
try. " 

The  first  radio  lecture  was  in 
Tientsin  in  1906.  The  audience 
was  the  staff  of  the  great  Gov- 
ernment Educational  Museum, 
established  in  a  confiscated 
temple.  Building  after  building 
had  been  filled  with  modern 
educational  equipment  of  the 
Western  type  to  supplant  the 
recently  abolished  "Literati" 
or  classical  educational  system 
dating  from  before  the  time  of 
Columbus.  A  part  of  this  equip- 
ment was  a  wireless  telegraph 
station.  No  one  on  the  staff 
knew  how  to  operate  it,  and 
so,  at  their  request,  the  writer 
put  it  in  order,  gave  them  a 
lecture  and  started  this  group 
in  radio. 

Later,  the  writer  constructed, 
in  the  "  Y"  Lecture  Laboratory 
at  Shanghai,  a  spark  station 


that  was  completely  dissectible  and  connect- 
able  in  a  great  number  of  ways.    This  did 
several  years'  service  until  superseded  by  a 
modern  vacuum-tube  outfit. 


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THE   PORTABLE   STATION  RE- 
CENTLY USED 


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PROFESSOR  ROBERTSON  S 
LICENSE 

Title  page  of  document  issued  for 
radio  lecture  campaigns.  As  will  be 
noted,  this  is  "Number  One."  It 
happens  that  Dr.  Robertson  holds 
another  "One",  also  issued  by  the 
Republic  of  China,  with  a  date  ten 
years  earlier — in  1912 


HIS  station  (shown  in  the 
picture  on  the  opposite 
page)  was  used  in  the  Victory 
Day  celebration  in  New  York 
in  1 91 9,  and  a  year  later  was 
built  into  a  traveling  lecture 
unit  in  our  Shanghai  Labora- 
tory. It  has  power,  sending, 
receiving,  and  amplifying  units. 
It  uses  two  five-watt  W.  E.  "  E  " 
power  tubes,  one  as  oscillator, 
the  other  as  modulator  on  the 
Heising  system.  For  reception 
W.  E.  "  J  "  tubes  are  used,  a  de- 
tector and  two  stages  of  audio- 
frequency amplification.  For 
the  loud  speaker  three  stages  of 
amplication  are  added,  the  last 
through  an  "  E"  tube  to  handle 
the  greatly  increased  energy. 
The  panels  turn  back  and  down 
into  the  base  which  shuts  up 
like  a  jack-knife,  completely  en- 
closing the  panels.    The  tables 


LI  YUAN  HUNG,  RECENT  PRESIDENT  OF  THE  REPUBLIC  OF  CHINA,  AN  ENTHUSIASTIC  PATRON  OF  THE 

POPULAR  SCIENTIFIC  LECTURES 

He  is  shown  with  his  son  and  daughter  and  Professor  Robertson.    The  apparatus  in  the  picture  was  built  for  this 
lecture  work  and  was  mounted  on  panels  so  as  to  be  accessible  from  front  and  rear,  allowing  every  detail  to  be  followed 
out.    Two  5-watt  tubes  were  used  for  transmitting,  and  for  reception,  a  detector  and  two  stages  of  A.  F.  amplification 
were  used,  three  more  stages  being  added  when  the  loud  speaker  was  employed 


in  front  turn  back  and  lock  together  making 
the  cover,  and  the  outfit  becomes  a  strong 
trunk  ready  for  the  road. 

The  energy  is  supplied  by  two  175-ampere 
storage  batteries  which  in  turn  drive  a  motor 
generator  giving  350  volts  plate  current.  A 
suitable  switch  enables  one  voltmeter  to  read 
all  pressures.  All  supply  current  passes  through 
one  ammeter,  so  by  subtraction,  the  consump- 
tion of  any  unit  of  the  station  is  determined. 
The  station  can  be  opened  or  closed  in  about 
ten  minutes.  A  folding  frame  giving  a  10-foot 
square  loop  provides  for  short  distance  trans- 
mission and  reception,  while  a  switch  throws 
over  to  an  antenna  with  which  long  distances 
can  be  had  on  both  transmission  and  reception. 
An  exact  duplicate  of  this  station  in  another 
trunk  provides  for  complete  two-way  demon- 
strations over  short  or  long  distances. 

This  quite  possibly  was  the  first  radio  tele- 
phone station  mounted  on  a  Chinese  wheel- 
barrow, and  in  this  form  our  preliminary  tests 
were  made  between  the  laboratory  and  various 


positions  on  the  streets  of  Shanghai.  The 
temporary  loop  may  be  seen  supported  by  the 
mast  from  the  front  end  of  the  barrow  (page 
384.) 

On  the  opposite  page  is  shown  the  title  page 
of  the  amateur  license  issued  to  the  writer.  Of 
course  all  the  lecturing  has  to  be  done  in 
Chinese.  The  radio  lecture  generally  begins: 
"Wo-men  chin-tien  wan-shang-ti  ti-mu  shih 
wu  hsien-tien-hwa. "  "The  subject  of  our 
lecture  to-night  is  the  radio  telephone." 

With  the  portable  apparatus  described,  we 
started  down  the  hundreds  of  miles  of  coast- 
line to  South  China  and  began  at  Hongkong. 
The  British  Navy  gave  fine  cooperation  and 
we  installed  our  broadcasting  station  on  one 
of  their  cruisers.  To  our  delight,  we  found 
that  it  worked  across  the  spacious  harbor  and 
could  be  amplified  and  made  clearly  audible  to 
the  large  audiences  gathered  in  the  "  Y " 
auditorium  on  the  precipitous  mountainside 
upon  which  the  city  is  built. 

In  Canton,  the  first  lecture  was  before  the 


384 


Radio  Broadcast 


officials  of  the  South  China  Government.  Our 
old  friend.  Premier  Wu  Ting  Fang  (whom  many 
of  you  will  remember  as  China's  Minister  to 
America)  was  present  and  just  as  keen  and 
penetrating  in  his  questions  as  when  he  fasci- 
nated so  many  American  audiences  in  years 
gone  by. 

The  Canton  "  Y  "  has  a  fine  new  plant,  and  to 
the  auditorium  came  three  audiences  per  day. 
Of  all  I  enjoyed  none  so  much  as  the  group  of 
seventy  students  in  a  technical  series  on 
"Radio,"  with  a  view  to  the  further  develop- 
ment of  the  spirit  and  method  of  science  in  the 
city  of  Canton. 

At  Amoy,  the  smallest  city  on  the  whole 
trip,  C.  J.  Wang,  the  able  Chinese  Secretary, 
and  John  Bradshaw,  his  American  associate, 


EXPERIMENTING  WITH  A  LOOP  TRANSMITTING  AND  RECEIVING 
STATION  IN  SHANGHAI 


have  a  tremendous  grip  on  the  town.  They 
put  up  a  special  auditorium  seating  over  2,000 
people,  and  to  this  on  one  day  came  7,800, 
with  a  total  for  the  first  four  days  of  17,800, 
supplemented  by  a  later  four-day  campaign 
of  over  10,000,  making  a  total  of  more  than 
27,000  people.  Not  only  were  there  large 
numbers,  but  the  character  and  appreciation 
of  the  audiences  were  of  a  high  order. 

A  unique  event  was  made  with  the  co- 
operation of  the  Chinese  Navy,  on  a  cruiser  on 
which  we  installed  our  broadcasting  radio- 
phone. The  other  apparatus  we  erected  seven 
miles  up  the  bay  at  a  new  educational  centre 
called  "Chi  Mei"  (The  Assemblage  of  the 
Beautiful).  Here  I  was  privileged  to  speak 
to  an  audience  of  1 ,600,  and  great  was  their  de- 
light to  hear  the  voice  of 
my  associate,  Mr.  Han,  and 
then  a  musical  program 
coming  across  the  seven 
miles  of  mountain  and  sea. 

The  occasion  was  the 
opening  of  a  new  depart- 
ment of  what  is  building 
intoAmoy's  two  million  dol- 
lar University;  the  gift  of 
Mr.  Tang  Ka.Ki,  now  a 
wealthy  rubber  grower  who, 
in  times  of  business  depres- 
sion, has  even  worked  as  a 
ric-sha  coolie,  and  who,  out 
of  these  great  octaves  of 
humanizing  experience,  is 
now  devoting  himself  and 
all  that  he  has  to  the  put- 
ting forward  of  education  in 
his  native  province  after 
years  of  strenuous  business 
at  Singapore. 

In  Foochow,  I  found  my 
old  friend  Governor  Li  Hou 
Chi.  He  was  immensely  in- 
terested in  the  lecture  mes- 
sage. He  appointed  his  chief 
officials  to  attend,  got  up  a 
fine  dinner  in  his  palace, 
urged  me  to  get  to  him  as 
soon  as  possible  data  for 
linkingup  the  different  cities 
of  his  province  by  wireless 
telephone,  and  then  provid- 
ed a  contribution  sufficient 
to  cover  the  local  expenses 
of  the  lecture  campaign. 


10,000  Miles  of  Radio  Lectures  in  China 


385 


But  even  greater  was  the  appreciation  of  a 
mission  college  student  who  sat  in  the  front 
seat  at  every  lecture  and  afterward  wrote: 
"O!  my  teacher.  I  am  very  grateful  toward 
you  for  having  come  to  us.  I  have  got  lots  of 
things  from  you.  My  schoolmates  wish  me  to 
speak  on  what  you  have  taught  in  the  special 
wireless  telephone  class,  so  may  I  see  your  book 
on  the  Audion  for  I  not  yet  understand  it.  1 
desire  to  be  your  student  or  servant  after  have 
graduated  from  college  this  year,  whereby  I 
have  the  opportunity  to  learn  from  you  the 
electricity.  .  .  .  You  are  very  kind  and 
have  done  big  service."  How  many  others 
were  interested  as  much  as  this  young  fellow  I 
do  not  know,  but  that  it  was  a  great  many  I  am 
sure. 

A  TRIP  TO  THE  NORTH 

IN  PAOTINGFU  is  the  great  Military 
1  Academy,  the  West  Point  of  China,  and  it 
was  a  fine  show  to  see  the  1,200  students  come 
marching  through  the  city  as  twelve  companies 
of  one  hundred  each.  Their  officers  all  came 
to  the  stage  and  examined  the  equipment,  and 


C.  H.  HAN  DEMONSTRATING  MONORAIL  APPA- 
RATUS 

Mr.  Han  has  been  associated 
with  Dr.  Robertson  for  18  years 


PROFESSOR  CHARLES  H.  ROBERTSON 


then  we  had  a  most  appreciated  presentation, 
ending  up  with  exchange  of  messages  with  one 
of  their  wireless  telephone  squads  outside  the 
East  Gate.  Each  following  day  they  brought 
the  whole  radio  corps  to  the  technical  lectures, 
and  good  times  we  had!  The  initial  meeting 
was  followed  up  by  two  big  audiences  each  day 
from  the  schools,  merchants,  gentry,  and  other 
classes  of  that  interesting  old  capital. 

The  unusual  campaign  in  Peking  was 
initiated  by  working  day  and  night  in  the 
laboratory  of  the  China  Electric  Company, 
where,  with  the  help  of  their  radio  engineer, 
Mr.  F.  R.  Lack,  our  equipment  was  brought  up 
to  date.  The  meetings  were  held  in  that  fairy- 
land-like group  of  buildings,  in  the  centre  of  the 
city,  that  has  been  erected  by  the  Rockefeller 
Foundation  for  the  Union  Medical  College. 
It  ranks  high  among  the  medical  training 
institutions  of  the  world,  and  in  its  beautiful 
auditorium  all  the  meetings  of  the  Peking 
campaign  were  held.  But  better  even  than 
the  fine  surroundings  was  the  cooperation  of  the 
Peking  Board  of  Education  in  gathering  the 
audiences,  made  up  of  picked  students  from 
about  fifty  of  the  schools  and  colleges  of  the 
city. 

After  a  long  trip  through  the  wide  plains  of 
Manchuria  we  tackled  the  Yangtze  Valley. 

Our  ton  of  radio  and  lecture  equipment  was 
put  on  board  the  steamer  Kiang  Shun.  .  We 


386 


Radio  Broadcast 


started  up  river  at  daybreak.  Plains  gave  way 
to  mountains,  and  steaming  by  pagodas, 
lumber  rafts,  sailing  junks,  big  steamers,  and 
many  walled  cities,  we  debarked  four  days 
later,  six  hundred  miles  from  the  sea  on  the  wide 
swift  flowing  Yangtze  at  Hankow,  with  waves 
so  big  that  my  demonstrating  mechanics  were 
sea-sick  as  we  shifted  by  sailing  junk  to  a 
J  apanese  steamer  for  the  next  leg  of  the  journey 
to  Changsha. 

We  crossed  the  Tung  Ting  Lake,  the  "  Bull's- 
eye"  of  China,  and  after  an  all-day  run  up 
the  beautiful  Hsiang  River,  arrived  at  Chang- 
sha (Long  Sand),  the  thriving,  bustling  capital 
of  the  agricultural  and  mining  province  of 
Hunan. 

We  had  to  hustle  to  get  our  radio  telephone 
stations  up  and  working  for  the  official  meeting 
at  seven  o'clock  with  Governor  Chao  Hung  Ti 
in  the  chair,  and  the  principal  high  officials  and 
gentry  present.  It  was  an  appreciative  audi- 
ence, and  the  Governor  was  especially  gracious. 
We  effected  a  fine  exchange  of  messages  with 
the  American   Navy  ship  Villalobos  (One  of 


Admiral  Dewey's  prizes  from  the  Battle  of 
Manila  Bay).  Our  radio  reached  through  to 
them  strongly  and  their  signals  were  amplified 
by  our  receiving  set  loud  enough  for  an  audi- 
ence of  50,000 people.  When  the  meeting  ended, 
1  took  the  Governor  for  a  look  at  our  auxiliary 
radiophone  in  a  closed  room  on  the  other  side  of 
a  big  compound. 

When  we  were  through,  I  escorted  him  to 
his  sedan  chair  at  the  door.  He  was  soon 
seated  and  1  followed,  according  to  Chinese 
courtesy,  to  the  gate.  He  had  just  gained  the 
street,  thickly  surrounded  by  his  armed  body- 
guard, when — Bang!! — a  heavy  explosion,  and 
I  saw  the  chair  careening  through  the  smoke, 
and  stepping  over  the  threshold  found  nine 
wounded  people  moaning  and  crying  on  the 
stone  flagging,  from  the  missiles  of  the  bomb 
thrown  from  somewhere  in  the  darkness.  The 
soldiers  grabbed  the  shafts  and  got  away  with 
the  Governor  unharmed  to  his  palace.  Later 
we  learn  that  seventeen  were  wounded.  One 
of  his  chair  coolies  died  shortly  after.  How 
harrowing  an  experience  this  is  one  doesn't 


CADETS  OF  THE  WEST  POINT  OF  CHINA  IN  THE  TEMPLE  OF  THE  GOD  OF  WAR  IN  PAHOTINGFU 
Two  officers  of  the  Military  Radio  Telephone  squad  are  on  the  stage.     The  charts  in  Chinese  at  the  back  of  the  stage 
summarize  the  applications  of  radio.    During  the  last  two  years  about  four  hundred  such  audiences  have  gathered  for 

these  radio  lectures  in  China 


10,000  Miles  of  Radio  Lectures  in  China 


387 


3mm 

PART  OF  AN  AUDIENCE  IN  FOOCHOW 
This  was  a  combination  meeting,  at  which  Eddy  spoke  on  religion  and  Robertson  on  science 


realize  until,  after  having  gotten  the  wounded 
on  stretchers  to  the  Red  Gross  Hospital,  one 
washes  off  the  blood  and  grime  and  turns  in 
late  at  night. 

The  next  day  the  pressure  began.  Popular 
lectures  at   10:00  and  4:00,  technical  radio 


lecture  at  2:00  and  science  and  religion  forum 
at  7:00  with  an  attendance  for  the  day  just 
beyond  3,000.  There  was  a  keen  interest  shown 
by  the  audiences  and  fine  cooperation  by 
Kallam,  the  American  navy  operator  who  was 
with  us.    He  especially  appreciated  the  en- 


FOOCHOW  OFFICIALS  WHO  ATTENDED  LECTURES  BY   PROFESSOR  ROBERTSON 


388 


Radio  Broadcast 


AN  OFFICIAL  RECEPTION   BY  THE  MILITARY  AND  CIVIL  GOVERNORS  OF  KIANGSI  PROVINCE 


thusiastic  applause  of  the  audience  transmitted 
to  him  by  radiophone,  and  replied  with  an  apt 
Chinese  phrase — "Ting  Hao"  (Very  good). 

On  the  last  day  of  our  tour  came  a  final 
address  before  a  group  of  faculty  members  of 
a  great  Chinese  college.  Paul  Kwei,  Head  of 
the  Department  of  Physics,  got  his  big  impetus 
for  scientific  educational  work  in  two  of  our 
lectures  in  St.  John's  University  at  Shanghai, 
ten  years  ago.  The  total  attendance  in  Chang- 
sha  was  16,705. 

A  trying  twenty-hour  railway  trip  in  day 
coaches  brought  us  back  again  to  Hankow, 
just  in  time  to  catch  the  night  steamer  for 
Kiukiang,  twelve  hours  down,  and  there  we 
made  close  connections  for  the  train  to  Nan- 
chang,  the  capital  of  Kiangsi,  seventy  miles 
interior  on  the  south  bank  of  the  river. 

Again  a  week  of  eager  faces,  and  1  found  a 
Purdue-trained  engineer,  C.  E.  Draper,  ar- 
ranged to  take  charge  of  the  students  from 
the  technical  radio  series  part  of  the  program 
and  to  lead  them  in  their  studies  in  actual 
experimental  contact  with  this  fascinating 
subject. 

Twenty-four  hours  down  river  brought  us  to 
Anking,  the  proud  capital  of  Anhwei  Province. 
Here  we  found  the  American  Navy  Flagship 
Isabel  equipped  with  a  radiophone,  so  we  had 


beautifully  clear  communications  by  voice,  as 
well  as  by  telegraph,  to  the  immense  delight  of 
the  audiences  in  the  provincial  educational 
Association  lecture  hall. 

Another  week  of  eager  faces — three  meetings 
with  Governor  Hsu,  an  old-time  friend,  and  his 
official  family,  a  three-page  poem  in  Chinese 
from  one  of  the  auditors,  and  we  started  with 
light  hearts  for  a  sail  past  a  mile-long  flock  of 
wild  ducks  down  the  Yangtze. 

Here  we  arrived  home  in  Shanghai  again; 
and  a  strenuous  time  it  had  been.  The  cities 
visited  were  twenty-seven,  the  distance  more 
than  13,000  miles,  and  the  attendance  184,242. 
Not  only  were  there  great  numbers  but  also 
personalities.  Twelve  provincial  Governors 
and  twenty-five  national  and  ex-national 
officials,  including  two  national  ex-presidents, 
graced  the  meetings  with  their  presence,  and 
were  stirred  by  the  vision  of  science  in  the 
future  of  China,  and  of  the  contributions  to 
science  in  the  world  that  China  would  some- 
time make. 

A  friend  said:  "  It  looks  easy,  but  we  know  it 
is  not."  And  that  is  the  truth.  The  journeys 
took  us  into  four  main  regions  of  China.  In 
one  were  bandits,  in  another  famine,  in  the 
third  pirates  and  in  the  fourth  mutinous  and 
looting  soldiers.    Shortly  after  1  left  the  City  of 


10,000  Miles  of  Radio  Lectures  in  China 


389 


Wuchang 


"Long' 


the 

street  was  looted  and 
burned.  The  Governor  per- 
mitted the  looters  to  get 
away,  but  laid  an  ambush 
for  them  on  the  railroad, 
and  when  their  long  train 
pulled  in,  turned  on  the 
artillery  and  shot  the  train 
and  its  contents  to  pieces. 

A  RADIO  TRIP  TO  THE  MAN- 
CHURIAN  FRONTIER 

AFTER  a  series  of  travel 
l  adventures  on  the  dis- 
organized railways  of  China, 
early  this  year,  1  drew  near 
to  Mukden.  Major  Gao, 
aide  of  General  Chang 
(whose  guest  I  was  to  be  in 
Mukden),  met  me  two  sta- 
tions out  and  on  disembark- 
ing I  found  motor  cars  and 
army  transport  waiting. 

In  a  motor  placed  at  my 
disposal  for  the  visit,  and  in 
the  crisp,  sharp  northern 
winter  morning  I  went  to 
the  provincial  assembly 
building.  The  army  radio 
telephone  corps  had  erected 
the  antenna  masts.  In  less 
than  an  hour  we  were  set 
up,  all  ready  for  the  lecture 
except  for  the  testing. 
Throwing  in  the  switches,  I 
said:  "Wo-men  tsai  che-pien 
hswo  hua  ni-men  tsai  na- 
pien  ting  teh  lai  la  ma" — 
"We  here  speaking  you  there  hear,  eh?"  Im- 
mediately came  back  the  reply  from  their 
radio  corps  in  a  temple  outside  the  city:  "Wo- 
men che-pien  ting  teh  heng  hao" — "We  here 
hear  extremely  well."  After  a  little  more 
testing,  they  said:  "  If  you  will  listen  in  we  will 
call  Chang  Chun."  I  heard  them  calling  and 
in  a  moment  back  came  the  reply  from  Chang 
Chun,  200  miles  away. 

At  10  o'clock  in  came  my  first  audience,  a 
half  regiment  of  sturdy  Manchurian  soldiers. 
We  had  a  fine  time  together!  Immediately 
following  this,  came  the  first  of  a  series  of  eight 
daily  lectures  with  laboratory  work  for  the 
radio  corps. 
That  same  afternoon,   came  a   group  of 


THE  GOVERNMENT  RADIO  ENGINEERING  SCHOOL  AT  SHANGHAI 

In  the  centre,  "X",  is  Professor  T.  C.  Chang,  Dean  of  the  School.    With  him  are 
some  special  radio  students.    The  building  is  finely  equipped  with  class  rooms,  and 
"labs,"  and  an  operating  room  in  which  are  various  types  of  phone  and  telegraph 
sending  and  receiving  apparatus 


important   business   men   gathered   by  Joe 


Piatt,  our  wonder-working  "Y"  secretary, 
who  is  so  esteemed  in  Manchuria's  capital.  In 
the  evening  a  small  group  gathered  in  General 
Chang's  headquarters  office,  made  up  of  staff 
officers  and  influential  civilians,  for  an  informal 
chatty  hour.    Some  subjects  discussed  were 

1,  The   Stroboscope   and    Its  Revelations; 

2,  Glimpses  Into  Astronomy;  3,  Molecular 
Motions;  4,  Curious  Right-angle  Gyroscopic 
Reactions;  and  so  on  for  eight  days  in  suc- 
cession! 

The  life  of  Mukden  often  reminded  me  of 
pioneer  days  in  the  Dakotas.  It  is  an  im- 
mense prairie  land  bordered  on  the  east  by  the 
Pacific,  on  the  west  by  mountains  and  deserts 


39Q 


Radio  Broadcast 


THE      BRIDGE  OF  TEN  THOUSAND  AGES      AND  FOOCHOW  HARBOR — 
Atypical  panorama  of  the  "old  and  populous  land,"  which,  according  to  Professor  Robinson,  is  now  beginning- 


and  on  the  north  by  the  great  rivers  and  forests 
of  Siberia.  The  streets  are  crowded  with 
traffic  coming  in  from  the  country,  big  two- 
wheel  carts  (rims  recently  broadened  by  law) 
drawn  by  three  to  six  horses.  Markets  filled 
with  furs  from  muskrat  to  tiger.  One  day  my 
soldier-audience  failed  me.  They  were  out 
suppressing  a  bandit  uprising.  Everywhere  a 
great  stir  of  life.  Plans  for  agricultural 
development  on  quantity  scale,  companies  for 
exploiting  forests,  promotors  of  mines,  of 
electric-service  monopolies  and  of  new  railways. 
I  felt  1  ought  to  be  staking  out  a  claim,  organ- 
izing a  lumber  camp  or  opening  a  mine! 

On  the  last  day  General  Chang  gave  us  and 
his  staff  a  banquet  in  the  great  North  Camp 
four  miles  out.  It  was  a  stinging  cold  day, 
yet  the  big  military  band  marched  out  for  the 
occasion.  The  next  morning,  escorted  again 
by  the  ever-courteous  Major  Gao,  we  got  our 
i  ,500  lbs.  of  lecture  equipment  on  the  train  and 
started  back  again  for  the  Yangtze  and  home. 

It  was  a  great  experience,  but  of  it  all  nothing 
seemed  to  me  more  significant  than  the  quiet 
evenings  with  General  Chang  and  his  keen, 
intelligent  group  of  officers,  holding  informal 
discussions  on  science,  on  religion,  and  on  the 
moral  issues  of  life.  They  all  seemed  to  enjoy 
it  immensely,  and  so  did  I.  How  much  all  this 
will  count  in  the  potential  struggle  between 
Russia,  Japan  and  China  of  which  Manchuria 
is  the  future  stage,  I  know  not,  but  that  it  was 
in  the  right  direction,  and  that  it  has  given 
another  link  with  some  of  the  personalities 
that  will  loom  large  in  the  future  of  China,  I 
am  confident. 

Without  doubt,  the  greatest  handicap  to 
the  progress  of  radio  education  in  China  to-day 
is  the  bureaucratic  monopoly  of  the  military 


party  who  have  not  yet  raised  the  war  embargo 
against  the  importation  of  radio  equipment 
into  China.  It  took  me  no  less  than  two  months 
to  get  through  the  Customs  at  Shanghai  the 
lecture  equipment  for  educational  purposes — 
and  then  only  after  special  authority  had 
been  secured  from  Peking. 

One  of  our  keenest  supporters  and  patrons 
has  been  President  Li  Yuan  Hung.  Our  first 
meeting  with  him  in  our  lecture  work  came 
when,  as  a  Colonel  of  a  local  regiment  in  Wu- 
chang, in  191 1,  he  attended  a  science  lecture. 
A  few  weeks  later  he  was  instrumental  in 
starting  the  revolution  that  upset  the  Ching 
Dynasty  after  its  267  years'  rule,  helped  to 
establish  the  Republic  of  China,  became  its 
first  Vice-President,  and  then  President  of 
China. 

In  the  early  days  of  the  lecture  work,  it  was 
extremely  difficult  to  secure  the  cooperation  of 
American  business  men  and  firms.  Not  so, 
however,  with  the  Germans,  who  through  their 
agents  in  China  were  glad  to  provide  fine 
cooperation  in  equipment  and  publicity.  A 
visit  of  the  writer  to  America  in  1919  helped 
to  increase  American  support.  There  is  need 
however,  of  far  greater  foresight  and  vision 
and  more  extended  cooperation  of  American 
radio  and  scientific  organizations. 

Returning  to  Shanghai  I  found  that  "broad- 
casting" had  arrived  and  was  producing  that 
tidal  wave  of  interest  and  enthusiasm  with 
which  all  of  you  in  America  are  so  familiar. 

Now  is  the  time  for  constructive  propagan- 
da; a  Radio  Corporation  broadcasting  station 
has  been  started  in  Shanghai,  and  daily  pro- 
grams of  Western  and  Chinese  selections  are 
sent  out  and  the  same  great  enthusiasm  and  un- 
answerable demand  for  receiving  equipment  has 


Wanted:  A  Desert  Island! 


391 


— WITH   KUSHANG  MOUNTAIN   IN  THE  BACKGROUND 
-to  throb  with  interest  and  activity  in  applying  the  fruits  of  modern  science  to  its  social  and  industrial  life 


developed  in  Shanghai  that  so  many  of  you 
are  familiar  with  in  America. 

In  getting  ready  for  big  developments,  it  is 
the  plan  of  the  National  "Y"  Educational 


tutes  with  the  provision  for  amateur  teacher 
training,  literature  supply,  equipment,  etc.,  so 
that  there  may  increasingly  come  to  China  the 
great  blessings  that  radio  will  engender  in  this 


Department  to  initiate  special  training  insti-    old  and  populous  land. 


Wanted:  A  Desert  Island! 

The  Story  of  an  Attempt  to  Forget  Radio  and  All  Its  Dreadful  Associations 

By  ZEH  BOUCK 


THERE  was  a  time,  when  to  isolate 
myself  from  radio — from  its  induc- 
tances and  extravagances — was 
farthest  from  my  desires;  and  oc- 
casionally, even  now,  I  am  not  alto- 
gether antagonistic  to  it.  I  don't  mind  writing 
a  radio  article  now  and  then — it  returns  to  me 
a  fraction  of  the  money  1  have  squandered  on 
everything  from  coherers  to  power  tubes — or 
listening-in  once  in  a  while  to  WLC  handling 
traffic  in  a  way  that  shakes  the  dust  from  a 

thousand  memories!   But  one  can  have 

too  much  of  a  good  thing,  and  the  time  came, 
not  very  long  ago,  when  radio  and  I  decided  to 
see  less  of  each  other  (I'd  laugh,  were  it  not  so 
tragic!). 

After  disposing  of  a  motor-generator  and 
sundry  apparatus,  I  presented  an  incipient 
lunatic  next  door  with  my  antenna,  on  condi- 
tion that  he  swing  the  unsightly  lead  across  the 
courtyard  into  his  own  window.  Feeling  more 
or  less  like  an  emancipated  drug  addict,  I 
looked  forward  to  an  enjoyable  freedom.  But 
I  was  sadly  mistaken.  Generosity  may  be  a 
virtue — but  virtue  has  always  been  my  stumb- 


ling block.  My  neighbor  apparently  con- 
sidered that  services  went  with  the  aerial,  and 
he  dogged  my  steps  and  my  telephone  with  an 
implacable  demand  for  a  crystal  regenerative 
set!  With  the  usual  malignancy  of  neighbors 
across  the  court,  he  recommended  me  to  some 
dozen  of  his  fanatic  friends,  with  the  result  that 
instead  of  being  divorced  from  radio  I  was  all 
the  more  embroiled  in  its  iniquities!  Deciding 
to  finish  my  next  door  neighbor  once  and  for 
all,  I  sold  him  an  electrolytic  interrupter  with 
which  to  light  his  filaments.  When  his  three 
tubes  blew  out  (as  1  knew  they  would  the 
second  he  turned  them  on),  instead  of  being- 
disgusted  and  forever  through  with  me,  the 
leech  came  around  and  demanded,  not  my  life 
as  I  had  hoped,  but  a  scientific  explanation  of 
why  his  tubes  had  blown! 

That  finished  me — pitifully  so.  I  deter- 
mined to  leave  the  city,  to  seek  new  parts, 
(no,  no,  I  mean  new  places),  some  virgin  land; 
vowing  to  shun  radio  in  every  form  however  in- 
nocuous it  might  appear!  But  the  question  was, 
where  to  go;  in  what  direction  lay  my  escape? 

"  Finding  an  unpolluted  spot  is  going  to  be 


392 


Radio  Broadcast 


like  searching  for  a  catwhisker  in  a  haystack!" 
I  thought ;  which  paraphrasing  of  the  old  aphor- 
ism well  indicates  my  disordered  state  of  mind. 

Haysfackl   A-a-ah!    The  very  thing!  Back 

to  nature  farm-life,  cows,  sleepy  pigs — back 

to  those  far  regions  where  they  have  yet  to  learn 
the  value  of  silos  as  antenna  masts!  And 
visualizing  the  peace  and  antiquity  that  I 
desired,  Schoharie,  N.  V.,  my  ancestral  village, 
flashed  to  mind.  Schoharie,  backward  and 
somnolent,  lying  in  the  valley  of  the  same  name, 
between  slopes  that  farther  south  and  east  run 
into  the  less  lazy  majesty  of  the  Catskills. 
Schoharie!  A  great  soft  country,  like  a  sleep- 
ing cat,  indolently  beautiful,  with  hills  of  green 
and  tilled  gold  squares  isolating  it  from  "civili- 
zation." Down  in  the  centre  of  the  valley 
runs  the  twisty,  slow  Schoharie  River,  emptying 
later  into  the  Mohawk,  and  beside  the  river,  the 
twisty,  slow  Schoharie  train.  In  my  mind's  eye 
I  saw  myself  alighting  from  that  train  at  the 
little  station.    .    .  . 

W  ithout  more  ado  I  telegraphed  the  Mack- 
eys,  with  whom  I  had  previously  boarded.  It 
was  not  until  1  had  finished  packing  my  bag  that 
1  noticed  that  1  had  thrown  in  a  pair  of  phones, 
by  force  of  habit. 

The  next  day,  on  the  observation  platform  of 
train  51,1  breathed  a  sigh  of  relief  as  she  slowly 
pulled  out  of  Grand  Central  Terminal.  Good- 
bye to  radio!  But  fifteen  minutes  later  1  was 
dizzy  with  counting  antennas!  1  was  actually 
ill  by  the  time  we  passed  the  old  De  Forest 
tower  at  Highbridge.  As  we  sped  through 
Yonkers,  I  cast  a  final,  half  fascinated  glance  at 
a  huge  umbrella  type  aerial  (2ZS,  I  think),  and 
turned  to  my  paper,  carefully  folding  inside  the 
page  that  gave  the  broadcasting  programs. 

At  Albany,  I  changed  to  the 


Binghamton 


Local,  a  fairly  comfortable  train  when  stopped 
at  stations,  or,  as  is  quite  often  the  case,  be- 
tween them.  1  had  barely  settled  myself  in  the 
old  D.  &  H.  smoker,  when  a  native  son  of  the 
soil  dropped  into  the  seat  beside  me.  I  wig- 
gled over  to  the  window,  partly  to  give  him 
room  and  partly  to  escape  the  hazard  of  a  heavy 
basket  which  he  balanced  on  the  rack  above  me. 
My  companion  looked  me  over  with  disconcert- 
ing deliberateness,  and  taking  a  preliminary 
chew  from  a  package  of  Old  Cottage,  spat  and 
spoke. 

"  Going  out  far  this  way?" 

1  beamed  on  him  with  a  sudden  realization 
of  where  I  was.  At  last  1  could  converse  with 
some  one  in  a  language  in  which  "coil"  could 
mean  rope  and  spaghetti  was  something  to  eat. 

"Oh  not  very  far.  I'm  getting  off  at  the 
Junction.    It's  a  great  free  country  out  here!" 

"Uh  huh,"  and  he  chewed  away  unim- 
pressed, for  all  the  world  like  the  ruminating 
stock  he  doubtless  owned.  He  evidently  figured 
it  was  my  turn,  so  I  ventured: 

"Coin'  very  far  yourself?" 

"No,  I'm  jest  going  to  Delanson." 

"  Delanson,  eh?  You  don't  happen  to  re- 
member Dick  Mackey,  do  you?"  Dick,  years 
ago,  had  there  proprietored  the  best  hotel  in 
the  county.  He  taught  the  bartender  the 
ramifications  of  his  art,  until  his  license  was 
voted  away,  when  he  took  to  farming. 

"Dick!  I  should  say  I  do  reck'lect  him. 
Beint  he  up  in  Schoharie  now?" 

"  Right-o.  That's  where  I'm  going.  .  .  . 
Out  on  his  farm." 

"  Yep,  Dick's  a  good  fellow.  D'ye  know 
Russ  Deyo  up  in  Schoharie?" 

"  Russ?  Sure!  He  has  the  Ever-ready 
Storage  Battery  agency,  hasn't  he?" 


I  CAUGHT  A  GLIMPSE  OF  JED  WILKINS  IN  THE  EXPRESS  OFFICE 


Wanted:  A  Desert  Island! 


393 


RUSSELL  DEYO  S  FIVE-BULB  SET 
Which  gave  the  writer  a  surprise 

"  Reckon  he  has.  Russ  is  a  lively  boy,  Russ 
be.  Got  one  of  these  here  radios  now,  and  he's 
selling  'em  all  over  the  county.  Farmer  down 
by  Delanson  got  one  the  other  day  offin  him!" 

My  heart  sank.  I  made  a  mental  note  to 
keep  away  from  Russ  Deyo.  It  was  a  darn 
shame,  too,  for  we've  always  been  the  best  of 
friends.  "  Radio  all  over  the  county !"  That 
was  discouraging.  Well,  anyway,  I  knew  that 
Dick  had  two  hundred  acres  of  virgin  hillside, 
and  I  consoled  myself  with  the  thought  of  my 
coming  isolation. 

Then  my  curiosity,  whetted  by  fourteen 
years'  environment,  got  the  better  of  my  dis- 
cretion, and  I  asked: 

"What  do  you  farmers  think  of  this  radio, 
anyhow?" 

"  Well,  to  be  frank  with  ye,  we  don't  think  a 
hell  of  a  lot  of  it  " 

I  nodded  and  beamed  approvingly,  almost 
asking  him  for  a  chew  of  tobacco. 

"Well,"  1  pursued,  "doesn't  it  do  you  any 
good?  Don't  you  derive  any  benefit  from  the 
market  quotations  and  the  crop  reports,  and 
all  that  sort  of  stuff?  There's  the  weather 
forecasts — and  then,  don't  you  enjoy  the  con- 
certs?" 

"Weather  reports?  Huh!  I  reckon  I  kin 
gen'rally  figure  out  the  weather  'thout  any- 
body's assistance.  The  music's  all  right  for 
them  as  likes  it.  My  wife,  she  kinda  takes  to 
sech  tripe  .  .  .  but  then  she  ain't  re- 
sponsible. And  then  that  there  crop  report. 
Well,  half  the  farmers  don't  get  it  anyway, 
'cause  it's  sent  out  at  the  wrong  time,  'round 
seven  in  the  evening  when  we're  doing  chores. 
The  farmer  ain't  got  the  time  to  lissen  to  sech 
stuff ;  he's  got  work  to  do,  and  when  that's  done, 


he  goes  to  bed.  The  only  chanct  he's  got  is  in 
the  winter  when  work's  slack,  and  then  those 
market  reports  don't  do  him  any  good  'cause 
there  ain't  no  crops!" 

I  was  beginning  to  understand  what  was 
meant  by  "agricultural  depression."  My  ac- 
quaintance continued. 

"The  trouble  is,  I  guess,  "he  closed  his  eyes 
as  he  became  philosophical,  "that  most  of  us 
are  too  old.  It's  a  thing  for  the  young  people. 
There  ain't  no  doubt  in  my  mind  that  when 
they  perfect  it,  radio's  goin'  to  be  a  wonderful 
thing.  There's  heaps  of  opportunity  in  it. 
There's  lots  of  fortunes  that's  goin'  to  be  made. 
There's  a  chanct,  now,  for  a  young  man  like 
you  " 

I  excused  myself,  rather  abruptly  I  fear,  and 
stood  on  the  platform  until  we  had  jerked  out 
of  Delanson. 

Manly  Bellinger,  an  old  friend  of  mine,  met 
me  at  the  Junction,  and  1  settled  back  in  his 
Ford  delighted  to  abandon  the  Schoharie 
Express  and  its  attendant  evils.  But  while 
Manly  was  turning  over  the  engine,  1  caught  a 
glimpse  of  Jed  Wilkins  in  the  Express  Office, 
checking  over  a  collection  of  boxes  and  pack- 
ages, half  of  which  displayed  the  labels  of  some 
radio  company.  Well  we  started  off,  and  I  was 
soon  breathing  deeply  of  the  fresh  valley  air. 
As  my  spirits  rose,  I  asked  Manly  for  the 
village  scandal,  which  he  gladly  furnished  ad 
infinitum.  But  my  heart  sank  again  as  my 
chauffeur  mentioned  a  new  small-town  ini- 
quity, RADIO;  and  he  enthusiastically  pro- 
claimed that  Schoharie's  aristocracy  had  capi- 
tulated to  it! 

Prompted  by  the  instinct  of  self-preservation, 
I  directed  my  chauffeur  to  raise  the  dust  of  the 
back  street  when  running  through  the  town, 
and  under  no  condition  to  stop,  whether  for 


VAN    — A  RADIO  TRAGEDY 


394 


Radio  Broadcast 


MR.  SPADEHOLTZ  S  ANTENNA  SYSTEM  IN  THE  SCHOHARIE  HILLS 


blowout  or  earthquake.  Manly  was  somewhat 
taken  back. 

"Well,"  said  he,  obviously  disappointed,  "1 
kinda  told  Russ  Deyo  that  I  might  bring  you 
around  to  his  store  before  1  took  you  up  to  the 

farm  "    Manly  paused,  daunted  for  the 

moment  by  my  pallor  and  the  contrasting  dan- 
ger in  my  eyes.    "  yes  yes,  1  know  you 

didn't  particularly  want  me  to  tell  any  one  that 
you  were  coming  up  this  time,  but  I  just  figured 
it  out  to  myself,  I  did,  being  that  you  and  Russ 
are  such  good  friends.  .  .  .  And  then 
there's  Pert — Pert  Badgely  at  the  Newsroom. 
He's  got  the  agency  for  the  Specific  Electric 
Radios,  and  he  sorta  reckoned  on  seein'  you. 


He  said  he  had  a  couple  of 
questions  he  calculated  to 

ask  " 

"That's  all  very  interest- 
ing," I  broke  in  ironically, 
"  but  it's  contrary  to  orders. 
You  steer  clear  of  Main 
Street,  and  when  you  see 
Pert  and  Russ,  you  just  pass 
it  along  that  I  changed  my 
mind  and  went  to  Bermuda 
—  no,  better  yet,  to  the 
South  Sea  Islands!" 

BUT  the  farm  was  Para- 
dise! The  weather  was 
lazy  and  perfect,  not  a  single 
stretch  of  wire  polluting  the 
blue  depths  of  the  sky.  The 
trees,  light  with  the  soft 
verdure  of  early  summer, 
swung  their  green  laurels 
unstayed  or  weighted  by 
unsightly  insulators  and  spreaders.  Not  even  a 
telephone  or  electric-light  wire  did  I  see,  and  I 
rejoiced  in  my  perfect  isolation.  1  settled  down 
to  a  quiet  existence,  and  read  extensively — The 
Dairyman' s  League  News,  The  Schoharie  Re- 
publican and  County  Democrat,  and  the  Sears 
&  Roebuck  Company  catalogue  (this  last  only 
until  1  came  to  the  radio  department).  Bui 
such  tranquility  could  not  last,  and  it  came  to 
a  tragic  conclusion  two  days  after  my  arrival, 
when  Russ  Deyo  drove  up,  and  burst  in  on  me. 

"Well,  well,  Jack!  I  sort  of  thought  I'd  find 
you  up  here,  though  Manly  didn't  like  to  admit 
it.  Well  I  suppose  you  came  up  here  to  dope  out 
some  new  radio  ideas  all  by  your  lonesome!" 


THE  NEAT  APPARATUS  OF  MR.  SPADEHOLTZ 
Both  cabinets,  the  honeycomb  coils,  loop,  and  key  were  all  made  by  him  in  his  amateur  workshop 


Wanted:  A  Desert  Island! 


395 


I  shook  hands  with  him,  though  his  words 
had  somewhat  rubbed  my  fur  the  wrong  way, 
and  before  I  could  denounce  such  calumny, 
Russ  elaborated  on  his  delusion. 

"  1  bet  you  miss  your  set  out  here.  Nothing 
to  do,  no  signals  to  listen  to.  Well,  I  think  we 
can  make  up  for  that  a  little  bit.  I've  got  a 
peach  of  a  little  set  down  at  the  house  you  can 
fool  around  with." 

I  began  to  protest,  but  my  friend  cut  me 
short. 

"Not  at  all,  Jack.  It's  not  the  least  trouble. 
I'm  only  too  glad  to  let  you  play  with  the  set. 
To  tell  you  the  truth  I'm  rather  proud  of  that 
little  instrument,  and  I'd  like  to  have  you  look 
'er  over.  Come,  you're  not  doing  anything  this 
afternoon,  why  not  let  me  run  you  to  town  and 
show  it  to  you?" 

"No,  no,  Russ,"  I  expostulated  (rather 
feebly),  "  I  don't  want — well  to  tell  you  the 
truth,  I  didn't  come  out  here  to  " 

"Now,  I  told  you  before,  Jack,  it's  not  the 
least  bit  of  trouble,  and  the  Missus'll  be  glad 
to  see  you." 

I  capitulated;  I  couldn't  offend  Russ,  so, 
letting  him  continue  to  think  that  he  was  doing 
me  a  favor,  I  made  up  my  mind  to  get  it  over 
with  as  soon  as  possible.  As  we  drove  past  the 
stables,  Russ  called  back  to  the  folks  that  I 
would  not  return  to  supper,  and  before  I  could 
assure  them  that  I  most  certainly  would  be 
back  in  one  half  hour,  we  were  around  the 
corner  and  out  of  range.  I  sat  glumly  in  the 
car,  watching  the  little  dashboard  ammeter 
jump  back  and  forth  as  we  lurched  over  the 
hillside  road.  But  the  little  instrument  soon 
called  forth  unpleasant  memories,  so  I  wrenched 
my  eyes  from  it,  and  made  a  sorry  endeavor  to 
be  pleasant. 

"I  suppose  WGY  is  about  all  you  can  get 
around  here  on  a  crystal  set,"  I  suggested,  try- 
ing to  show  an  interest  in  the  apparatus  which 
he  was  taking  me  to  see. 

"  Yes,  that's  about  all  we  can  get." 

"Crystals  don't  work  very  well  on  single- 
circuit  sets,  do  they?" 

"No,  I  guess  not." 

I  was  deciding  that  Russ  didn't  know  a 
great  deal  about  receivers,  but  nevertheless  I 
persevered  in  talking  intelligently  about  a 
simple  set. 

"  Do  you  use  a  synthetic  crystal?"    I  asked. 
"No;  no,  I  never  heard  of  them.    What  are 
they?" 

Quite  discouraged,  I  said  a  few  thing  about 


THE  LAYOUT  OF  MARSTON  VROOMAN 

In  Middleburg,  N.  Y.    A  set  that  takes  one  back  to  pre- 
war amateur  days 


metal  sulphides,  wondering,  for  the  want  of 
something  more  cheerful  to  do,  what  sort  of  a 
mineral  he  used  under  the  bent  safety-pin, 
which  contrivance  I  was  now  convinced  con- 
stituted his  "little  instrument." 

Five  minutes  later  Russ  Deyo  introduced  me 
to  his  five-bulb,  two  radio,  detector,  and  two  audio 
set!  I  was  simultaneously  introduced  to  his 
dog,  Van  (whom  I  renamed  Pan,  as  being  short 
for  Pandemonium),  and  I  spent  the  next 
ten  minutes  between  pretending  to  enthuse 
over  the  apparatus  (which  really  deserved 
commendation)  and  warding  off  the  attacks 
of  the  mongrel  who  was  sedulously  destroying 
my  right  trouser  leg.  I  looked  first  at  the 
glowing  bulbs,  and  then  at  the  dark  circles 
under  my  friend's  eyes,  and  comprehended.  I 
determined,  at  least,  to  save  his  reason.  As 
Russ  left  the  room  for  a  moment,  I  called  to 
Van,  who  had  relinquished  my  ankle  in  favor 
of  the  pedals  on  the  piano,  and  sicked  him  on 
the  radio  set. 

"Get  'em,  Van!"  1  hissed,  pointing  to  the  five 
tubes.    "Rats!    Eat 'em!" 

Van  cocked  his  eye  that  was  airdale  (the 
other  was  partly  fox  terrier),  and  threw  one 
comprehending  glance  at  the  apparatus.  He 
yelped  pitifully,  and  flew  from  the  room,  his 
tail  between  his  legs.  That  dog  was  the  only 
male  member  of  the  Deyo  family  with  sense 
enough  to  be  scared  of  the  thing.  (Poor  Van. 
well  might  he  fear  it!    He  is  now  dead,  and  his 


396 


Radio  Broadcast 


THE  UNASSUMING  SHOP  OF  MR.  DEYO 

From  which  he  dispenses  radio  equipment  to 
Schoharie,  N.  Y.,  and  throughout  the  county 

spirit  flown  at  a  speed  which  I  hope  is  greater 
than  186,000  miles  a  second.  He  ran  into  a 
moving  automobile  one  night  in  a  precipitate 
rush  to  escape  from  the  loud-speaker.) 

Russ  returned  a  moment  later,  his  face  beaming. 

"Come  on,  Jack,  we're  off!  I've  got  a  treat 
for  you.  We're  going  up  to  Spadeholtz's  farm 
on  the  hill.  He's  got  one  of  the  neatest  little 
sets,  and  he  made  every  bit  of  it  himself  on  the 
farm.    He's  got  antenna  masts,  and  " 

"  I'm  sorry,  Russ,  but  1  must  get  back  to  the 
Mackeys'.  Supper,  you  know,  and  besides — " 
But  my  protests  were  futile. 

"  Nonsense,  you're  eating  with  me.  Come  on \" 

By  this  time  1  was  prepared  to  look  for  some- 
thing better  than  a  crystal  set,  and  under  hap- 
pier circumstances  I  should  have  admired  the 
ingenuity  of  the  lad  who  built  his  set  on  the 
lonely  hillside.  A  year  before,  1  could  have  ap- 
preciated the  antenna  and  its  supports,  the 
cleancut  appearance  of  the  apparatus,  the 
audion  sockets,  transmitting  key,  loop,  honey- 
comb coils  and  omnigraph,  all  home  made!  As 


it  was,  I  assimilated  these  details  quite  dis- 
passionately, and  made  not  the  slightest  pro- 
test when  Russ  announced  that  he  was  now 
going  to  show  me  another  station  located 
somewhere  in  Middleburg  owned  by  one  Mars- 
ton  Vrooman.  1  was  led,  unresisting,  much 
after  the  manner  that  a  criminal  is  conducted 
to  and  from  the  scenes  of  his  crime. 

Young  Vrooman's  station  brightened  me  a 
little,  for  in  appearance  and  layout,  it  was  remi- 
niscent of  the  old  amateur  days  before  the  war. 
But  my  retrospective  thoughts  brought  the  evils 
of  to-day  into  a  more  prominent  relief,  and  1 
soon  sank  back  into  my  "slough  of  despond." 

I WAS  depressed  the  next  day,  and  in  my 
melancholy,  the  blue  sky  seemed  hidden  be- 
hind a  network  of  a  thousand  antennas.  I 
went  to  town  that  evening,  hoping  to  lose  my- 
self, mentally  and  physically,  in  the  motion 
picture  theater.    But  Russ  saw  me  first. 

"Hello  there,  Jack!"  he  beamed.  "I've 
been  wanting  to  get  up  to  you  all  day,  but  I've 
been  as  busy  as  the  deuce.  I'm  going  to  take 
you  down  to  Charlie  Holmes's,  you  remember 
him.    He's  got  quite  a  set,  and  I  know  you'll  be 

interested  in  it.    I'll  get  the  car  " 

"No!  No  you  won't,  Russ!"  This  time  I 
would  be  firm.  "Impossible!  I'm  going  to 
the  show,  and  nowhere  else."  But  Russ 
smiled  as  cheerfully  as  ever. 

"All  right,  fine!"  he  assented. " Hattie 
Meyers  has  a  set  there  in  the  theater.  It's  the 
same  as  Charlie  Holmes's,  in  fact  he  installed 
it.  .  .  ."  and  in  half  swoon  I  heard  only 
vaguely  the  details  of  " .  .  .  Westinghouse 
.  .  .  two  step  .  .  .  Western  .  . 
loud-speaker.    .    .  ." 

As  we  left  the  theater,  two  tortured  hours 
later,  Russ,  always  painfully  enthusiastic, 
grabbed  my  arm. 

"Now,  I'm  coming  up  for  you  to-morrow 
night,  Jack.  The  firemen  are  giving  a  combined 
party  and  radio  dance,  and  I  know  you'll  want 
to  be  there.  In  fact  you  can  operate  the  set. 
Well  good  night,  Jack!" 

"Good-bye,  Russ,"  I  said,  "Adieu!" 
The  next  morning  Manly  Bellinger  made 
what  reparation  he  could,  and  in  his  Ford,  he 
sneaked  me  away  from  Schoharie  before  the 
sun  was  fairly  up.  I  didn't  dare  brave  the 
train.  I  had  just  been  reading  about  the  receiv- 
ing experiments  on  the  Lackawana  Railroad  and 
Heaven  only  knows  what  atrocities  Russ  might 
have  committed  on  the  Schoharie  Limited. 


WD-n's  and  WD-12's  on  the  aging  table.  The  tubes  are  kept  on  this  table  one 
hour  to  increase  the  possible  electron  emission  and  to  test  for  the  degree  of  vacuum 


How  Vacuum  Tubes  are  Made 

Following  the  WD-ll's  and  WD-12's  Through  One  of  the  Plants  in  Which  They  are  Made 

By  W.  W.  RODGERS 

Westinghouse  Electric  and  Manufacturing  Company 

This  is  the  first  time  that  an  article  has  been  published  in  a  radio  magazine  describing  and  illustrating  the 
important  steps  in  the  manufacture  of  vacuum  tubes.  Except  for  minor  modifications  and  a  difference  in 
the  exhausting  process,  all  vacuum  tubes  are  made  in  a  way  much  like  the  dry-cell  tubes  here  described 
by  Mr.  Rodgers. — The  Editor. 


IF  ONE  were  asked  what  single  factor  has 
made  radio  universally  popular  in  America, 
the  answer  might  not  be  as  difficult  as  it 
first  seems.  For,  of  the  many  things  intro- 
duced into  the  radio  market  for  the  benefit 
of  amateur  and  fan,  the  dry-cell  vacuum  tube 
stands  supreme  in  the  number  of  radio  enthu- 
siasts it  has  added  to  the  list  of  those  who 
nightly  listen-in.  Thousands  of  new  fans  were 
created  as  soon  as  the  dry-cell  tube  began  to  be 
sold  in  quantities. 

This  little  tube  eliminated  a  sharp  class  dis- 
tinction in  the  radio  world.  Before  it  came 
there  were  the  crystal  detector  users  and  the 
vacuum-tube  users.  Crystal  detector  sets  were 
numerically  superior  to  vacuum-tube  sets  when 


all  that  could  be  obtained  was  the  six-volt  tube 
operated  from  a  heavy  and  expensive  storage 
battery.  People  who  could  not  afford  these 
items  had  to  be  content  with  crystal  detectors, 
and  thus  were  very  limited  in  their  range  of 
radio  entertainment. 

Then  came  the  dry-cell  tube,  changing  this 
condition.  The  purchaser  of  the  one-volt  tube 
could  procure  his  current  from  a  40-cent  dry 
cell;  whereas  the  storage  battery  needed  for 
a  six-volt  tube  cost  from  ten  to  twenty  dollars. 
There  was  such  a  rush  on  the  part  of  the  public 
to  buy,  that  for  a  time  the  manufacturers  were 
swamped.  In  fact,  two  great  shortages  have 
occurred  in  the  vacuum  tube  supply  since  they 
were  first  placed  on  sale. 


398 


Radio  Broadcast 


FIG.  I 

The  short  glass  tube  has  a  flare  on  one  end  and  its 
other  end  has  been  melted  and  pressed  down  around  the 
five  wires,  which  are  imbedded  firmly  in  the  glass.  Note 
that  there  are  five  wires  in  the  glass  press,  but  only  four 
leads  come  through  the  flared  opening.  The  fifth  wire 
is  a  blind  which  acts  as  a  support,  later,  for  the  plate 

These  shortages  are  not  likely  to  occur  again 
as  they  occurred  with  a  type  of  tube  made  by 
one  company,  which  at  the  time  was  the  only 
concern  in  America  capable  of  producing  these 
tubes  in  quantities.  There  are  now  two  com- 
panies making  such  vacuum  tubes,  and  thus 
with  their  increased  facilities  a  much  larger 
production  is  available. 

The  first  commercial  dry-cell  vacuum  tube, 
the  WD-ii,  is  a  product  of  the  Research 
Laboratories  of  the  Westinghouse  Electric 
and  Manufacturing  Company  at  East  Pitts- 
burgh, Pa.  It  was  here  that  the  need  for  such 
a  tube  was  first  seen  and  the  research  work 
necessary  to  the  perfection  of  the  finished  tube 
carried  on. 

Early  in  radio  telephone  broadcasting  his- 
tory, after  the  public  had  indicated  its  interest 
in  the  concerts  and  the  possibilities  of  the  in- 
dustry were  realized,  the  need  for  a  vacuum 
tube  which  could  be  operated  at  low  cost  was 
clearly  seen.  It  was  apparent  to  the  men  who 
had  the  problem  to  solve  that  the  first  cost  of 
the  tube  was  not  what  prevented  an  almost 
universal  interest  in  radio,  but  that  it  was  due 
to  the  upkeep,  as  they  say  in  the  automobile 
world.  Storage  batteries  cost  money  to  buy 
and  to  keep  charged. 

Long  before  the  first  order  was  given  the 
Research  Laboratory  to  start  experimenting 
on  the  proper  material  for  a  low-voltage  fila- 
ment, preliminary  work  had  been  started  by 
the  research  engineers.  It  had  been  discovered 
that  a  new  filament  was  necessary.  This  fila- 
ment must  consume  a  very  small  amount  of 
current  yet  have  a  satisfactory  electron  emis- 
sion. 

However,  in  spite  of  the  preliminary  experi- 
menting on  the  tube,  it  was  nearly  eight  months 
before  the  Research  Laboratory,  which  re- 
ceived its  order  from  the  Company  officials  to 
start  developing  a  tube  having  the  WD-i  i  char- 
acteristics in  March,  1921,  was  able  to  furnish 
the  perfected  tube.    The  first  commercially 


practical  tube  was  completed  October,  1921. 
During  the  eight  months  intervening  a  new 
oxide-coated  filament  was  perfected  and  the 
WD- 1 1  type  designed. 

At  first  there  was  some  trouble  in  securing 
the  proper  type  of  worker — one  who  required 
no  small  degree  of  skill  in  the  various  stages  of 
assembly.  Girls  had  been  decided  upon  for  a 
large  number  of  the  manufacturing  operations, 
and  a  few  thought  that  it  would  require  a  long 
period  of  training  to  fit  them  for  the  work. 

While  the  organization  was  being  perfected 
the  Research  Laboratory  undertook  the  con- 
struction of  400  tubes.  This  order  came  in 
October,  1921.  With  an  augmented  force  the 
400  tubes  were  completed  in  a  short  time. 
Then  another  order  for  400  tubes  was  placed 
with  the  Research  Laboratory  and  upon  its 
completion,  another  and  still  other  orders. 
The  tube  became  popular  at  once  and  the  de- 
mand for  it  by  the  public  exceeded  expecta- 
tions. 

At  the  time  the  tubes  were  being  assembled 
in  the  Research  Laboratory,  a  section  of  the 
factory  in  East  Pittsburgh  was  being  equipped 
to  build  the  tubes.  The  men  and  girls  trained 
by  the  research  engineers  formed  the  nucleus 
of  the  larger  force  required  in  the  department  of 
the  Main  Works  where  the  tubes  are  now  as- 
sembled. Soon  this  department  was  building 
tubes  in  daily  increasing  quantities. 

Since  the  vacuum  tube  department  was 
given  the  task,  production  has  so  increased  that 


fig.  2 

The  filament,  plate,  and  grid  of  the  WD-11  and  WD-12 
dry-cell  tube.  Note  that  the  ends  of  the  filament  are 
held  by  two  clips  and  that  there  is  a  support  running 
from  the  upper  clip.  These  attachments  are  provided 
so  that  the  filament  may  be  spot-welded  to  its  support 


How  Vacuum  Tubes  are  Made 


399 


Mounting  the  filamen 
assembled  inner  unit 


now  the  average  number  of 
tubes  assembled  daily  is 
7,500.  This  is  quite  a  large 
quantity  when  one  con- 
siders the  care  necessary  in 
their  assembly  and  the 
number  of  tests  each  tube 
is  required  to  pass  before  it 
is  considered  ready  for  the 
purchaser. 

The  WD-n  and  WD-12 
tubes,  which  are  identical 
except  for  their  bases,  de- 
spite the  fragile  character  of 
the  materials  used  and  the 
great  care  and  skill  neces- 
sary to  their  proper  as- 
sembly, are  sturdy  bits  of 
apparatus,  well  adapted  to 
withstand  fair  handling  and 
give  efficient  service  during 
a  long  life.  Much  attention 
has  been  given  to  construct- 
ing them  so  that  they  might 
be  small  yet  not  at  all  del- 
icate. This  does  not  mean 
that  they  are  dropped  on  the  ground  to  test  the 
strength  of  the  glass,  nor  that  they  will  come  up 
smiling  after  having  22|  volts  connected  across 
their  filaments.  How  many  users  have  burned 
out  their  dry-cell  tubes  because  of  this  error! 
The  filament  voltage  should  not  be  more  than 
one  and  one-tenth  volts. 

There  are  two  main  units  in  these  tubes — 
the  outer  tube,  from  which  the  air  is  removed, 
and  the  assembled  inner  unit.  If  this  is  kept 
in  mind  and  if  it  is  understood  that  all  assem- 
bly is  done  on  the  inner  unit  which  is  then  in- 
serted in  the  outer  tube,  sealed  in  and  the 
outer  tube  exhausted  of  air,  the  various  stages 
of  manufacture  may  be  followed  very  easily. 

There  are  13  steps  or  processes  through 
which  the  parts  go  before  they  emerge  as  the 
complete  vacuum  tube.  There  is  a  test  made 
after  each  stage  of  the  assembly  and  still  further 
tests  after  the  tube  is  completed.  The  tests 
are  so  severe  that  a  tube  after  it  passes  through 
them  is  rarely  returned  from  a  customer  for 
failure  to  operate  correctly. 

The  raw  materials  from  which  the  com- 
pleted tube  is  made  consists  of  the  glass  blank, 
which  is  purchased  from  the  glass  manufacturer 
already  shaped — this  forms  the  glass  walls 
of  the  tube;  a  thin  glass  stem;  a  short  tube  of 
glass,  which  is  later  shaped  and  which  holds 


FIG.  3 

t — step  seven  in  the  assembly.    The  operator  is  holding  the 
in  her  hand  while  she  spot-welds  the  top  of  the  filament  to 
its  support 

the  wires  in  place  in  the  tube;  the  filament,  cut 
to  size  and  coated  at  the  East  Pittsburgh 
plant;  the  plate;  and  the  grid.  The  plates  are 
shaped  from  a  rectangular  piece  of  metal,  and 
the  grid  wires  are  wound  into  the  spiral  form 
they  take  in  the  completed  tube. 

All  these  units  can  be  seen  in  the  photographs 
of  the  assembly  process. 

The  first  step  in  the  process  is  the  making 
of  the  flare.  This  consists  in  heating  the  small 
tube  on  one  end  to  soften  it  and  then  spinning 
on  the  flare. 

It  will  be  noted,  if  one  looks  closely  (Fig.  1) 
that  there  are  five  wires  in  the  press  or  inner 
unit  of  which  four  run  through.  The  fifth 
wire  is  merely  a  blind  inserted  to  act  as  a  sup- 
port for  the  plate.  These  wires  are  white  at 
the  top  but  red  where  they  adhere  to  the  glass 
in  making  the  seal  tight.  Dumet  wire  is  used 
for  the  seal,  nickel  being  welded  to  it  at  the 
top.  A  copper  covering  is  necessary  so  that 
when  the  press  is  melted  to  hold  the  wires  at 
its  top,  a  gas-tight  joint  is  formed. 

The  placing  of  the  five  wires  in  the  press  is 
the  second  operation  of  the  assembly.  What 
this  resembles  with  the  five  wires  imbedded  in 
is  clearly  shown  in  the  photograph. 

Next  the  stems  are  cut  to  the  proper  length 
so  that  when  the  plate,  grid,  and  filament 


400 


Radio  Broadcast 


fig.  4 

The  assembled  inner  unit  complete,  with  grid,  plate,  and  fila- 
ment mounted.  The  flare  at  the  end  of  the  glass  mount  is 
used  for  sealing  in  this  assembled  inner  unit  to  the  glass  blank 


FIG.  5 

The  glass  blank  as  it  is  received  from  the  glass  factory 


(Fig.  2)  are  inserted  they  will  fit 
in  their  proper  places.  This  makes 
the  fourth  step  in  the  operation. 

Step  five  consists  of  mounting 
the  plate.  This  is  spot-welded  to 
its  support  by  a  girl  who  has  a 
special  machine  for  the  task. 

Step  six  consists  in  mounting 
the  grid.  This  is  also  spot- 
welded  at  the  top  and  bottom  to 
its  mounting. 

The  next  step  is  mounting  the 
filament  (Fig.  3).  This  filament, 
which  is  a  platinum  iridium  alloy,  coated  with 
an  oxide  of  barium  and  strontsium,  comes  to  the 
girls  already  cut  to  the  right  length,  properly 
tested  and  with  its  ends  ready  for  mounting. 
Mounting  the  filament  is  probably  the  most 
delicate  task  in  the  assembly  of  the  tube. 

There  is  a  good  reason  for  using  an  alloy  for 
the  vacuum-tube  filament.  Ordinary  metals 
are  not  used  because  they  are  not  as  strong  at 
the  temperature  to  which  they  are  subjected  as 
is  the  alloy.  Making  the  tube  strong  enough 
to  stand  the  wear  and  tear  of  daily  use  was 
ever  a  problem  before  the  research  department. 
All  sorts  of  metals  were  tried.  The  WD-i  1 
filament  has  a  long  life  which  accounts  for 
the  fact  that  it  will  give  service  for  a  pe- 
riod often  ranging  between  2,000  and  3,000 
hours. 

Step  seven  is  completed  with  the  mounting 
of  the  filament  (Fig.  4).  The  weld  press  is 
completed  and  is  ready  to  be  placed  in  the  glass 
blank  (Fig.  5),  which  first  must  be  prepared  for 
exhausting. 

Step  eight  in  the  process  is  called  tubulating 
the  glass  blank  (Fig.  7).  A  thin  point  of  flame 
is  blown  against  the  rounded  end  of  the  glass 
blank,  so  that  a  tiny  hole  is  melted  through. 
Then  the  glass  tube  is  welded  around  this 
hole.    The  blank  now  has  a  glass  tube  running 


from  its  end  (Fig.  6).  This  glass 
tube  is  attached  for  the  purpose 
of  exhausting  the  tube.  As  the 
other  end  of  the  tube  is  sealed  this 
end  remains  so  that  it  can  be  at- 
tached to  the  pumping  machines. 

The  next  step,  number  nine,  is 
termed  sealing-in  (Fig.  8).  When 
it  is  finished,  the  glass  weld  with 
its  mounted  plate,  grid  and  fila- 
ment and  the  four  wires,  running 
out  of  its  end,  is  firmly  sealed  to 
the  glass  blank.  The  flare,  first 
spun  on  the  press,  is  used  to  make  this  joint. 

At  this  point,  the  tube  resembles  a  completed 
vacuum  tube  except  that  it  has  no  base  and  has 
a  long  glass  tube  mounted  on  its  top. 

When  the  sealing  is  completed,  the  tube  is 
tested  for  leaks  in  any  part  of  it.  It  is  also 
tested  for  short  circuits  from  filament  to  grid 
and  from  grid  to  plate. 

Step  ten — exhausting  the  air  from  the  tube — 
is  a  very  important  one  (Fig.  9).  Before  arriv- 
ing at  this  stage,  a  getter  has  been  painted  on 
the  base  of  the  glass  weld.  It  can  be  seen  as 
the  white  dab  on  the  press  holding  the  five 
wires  in  place.  From  10  to  15  minutes  are 
required  to  exhaust  each  tube. 

In  exhausting  the  tube,  the  glass  stem  at  the 
top  is  inserted  in  a  piece  of  rubber  tubing 
which  leads  directly  to  the  pumps.  These 
are  two  in  number,  an  oil  pump  and  a  mercury- 
vapor  pump. 

A  covering  is  pulled  down  over  the  tubes. 
This  covering  serves  as  an  oven  to  bake  them 
at  a  temperature  of  4000  Centigrade  and  thus 
reduce  the  gas  content. 

Then  the  pumps  are  turned  on  and  the  tubes 
exhausted  to  a  pressure  of  one-millionth  of  a  mill- 
imeter of  mercury.  This  is  a  much  higher  point 
of  exhaustion  than  that  given  the  electric  lamp. 

As  the  tube  sits  in  the  holder,  it  is  surrounded 


The  glass  blank  with  its  stem  attached.  This  stem  is 
used  in  the  process  of  removing  the  air  from  the  tube 


How  Vacuum  Tubes  are  Made 


401 


by  a  coil  of  heavy  copper 
wire.  The  covering  is  now 
pulled  up  and  a  high-fre- 
quency spark  is  thrown  on 
this  surrounding  coil  to  test 
the  tube  for  cracked  glass. 

After  this,  the  plate  is 
heated  red  hot  by  an  oscil- 
lating current  having  a  fre- 
quency of  1,000,000  cycles 
— these  are  generated  by 
two  250-watt  tubes  similar 
to  those  used  for  trans- 
mitting purposes — to  re- 
move the  gas  from  the 
plates  and  metal  supports. 

Next  in  order  is  the  turn- 
ing off  of  the  plate  os- 
cillations and  heating  the 
filament  to  obtain  the 
proper  chemical  reaction  on 
the  filament  oxide  and  thus 
increase  the  possible  elec- 
tron emission. 

The  tip  is  now  sealed  off 
by  the  machine  operator  us- 
ing a  gas  flame,  which  he 
runs  around  the  bottom  of 
the  glass  tube  until  it  melts 
off  and  forms  the  tip. 
,  Finally  the  tube,  properly 
exhausted  is  removed  from 
the  machine,  complete  now 
except  for  the  base  (Fig.  10). 

The  tube  now  passes  through  several  stages 
of  inspection  before  the  bases  are  cemented  on. 
During  this  inspection,  the  tube  is  carefully 
looked  over  for  appearance  and  poor  tips, 
and  for  degree  of  vacuum.  Opposite  the  in- 
spectors who  take  the  tube  at  this  stage  there 
is  a  box  into  which  the  rejected  tubes  are 
tossed  and  smashed  to  fine  bits. 

Step  number  eleven  is  cementing  the  base 
to  the  tube.  Just  before  "basing,"  a  small 
glass  stem  is  slipped  over  each  of  the  four  leads 
to  prevent  any  shorts  at  this  point.  The  base 
is  filled  with  a  cement,  an  operator  draws  the 
four  wires  through  the  stems  in  the  bottom  of 
it,  and  the  tube  with  its  base  attached  is  placed 
in  a  machine  which  bakes  the  base  on  firmly. 
Included  in  the  basing  operation  is  the  soldering 
of  the  bottom  of  the  tips  on  the  base  and  round- 
ing off  the  ends  of  the  stems.  An  operator 
dips  the  stems  in  a  solder  pot  so  that  the  wires 
running  through  the  stems  are  soldered  firmly 


Tubulating 
end  of  the  g 


FIG.  7 

the  blank.  A  tiny  hole  is  melted  in  the  rounded 
ass  blank  and  around  this  hole  is  sealed  a  glass  stem 

in  place.  To  make  a  neat  job,  the  stems  are 
next  placed  in  a  machine  so  that  they  are 
rounded  off  properly.  Just  look  at  the  tips 
on  the  base  of  your  vacuum  tube  to  understand 
this  operation. 

Thus  when  the  tube  reaches  this  stage  it 
resembles  the  one  used  in  the  receiving  set. 
But  it  still  has  some  tests  and  processes  to  go 
through  before  it  can  be  called  completed. 

The  next  step  is  a  test,  and  while  it  is  given 
no  number  in  the  order  of  assembly,  it  is  im- 
portant. This  test  is  termed  lighting  out  the 
tube  (Fig.  1 1).  An  operator  places  the  tube  in 
a  base  connected  to  three  electric  lamps;  one 
red,  one  blue,  and  one  white.  The  red  lamp  is 
in  series  with  the  grid,  the  blue  lamp  is  in  series 
with  the  plate  and  the  white  lamp  is  in  series 
with  the  filament.  If,  when  the  tube  is  placed 
in  this  base,  one  of  the  lamps  glows,  it  is  dis- 
carded, for  it  plainly  can  be  seen  that  the  wires 
are  short-circuited  and  the  tube  is  unfit  for  use. 


402 


Radio  Broadcast 


fig.  8 

In  this  process,  the  assembled  inner  unit  is  sealed  by 
means  of  its  flare  to  the  bottom  of  the  glass  blank 


tive  grid  current.  During 
the  aging  process,  the  getter 
absorbs  such  gases  as  might 
remain  in  the  tube. 

After  leaving  the  aging 
table,  the  tubes  are  stored 
for  three  days.  This  is 
time  enough  to  determine 
whether  there  are  any  air 
leaks.  After  this  final  stor- 
age, they  are  again  tested 
for  all  circuits,  filament 
emission,  degree  of  vacuum 
and  appearance  and  are 
ready  for  shipping. 

The  final  stage  is  the 
packing.  Those  who  have 
purchased  the  WD-i  i  know 
how  carefully  it  is  packed 
in  its  cardboard  box  with 
many  layers  of  packing  ma- 
terial wrapped  around  it. 

The  process  of  assembl- 
ing these  tubes  is  one  that 
is  long  and  tedious,  calling 
for  the  utmost  skill  on  the 
part  of  the  various  opera- 
tors.   In  assembling  the 


Those  of  the  tubes  which 
pass  this  test  go  on  to  the 
next  stage.  This  is  a  test 
and  a  process  combined  for 
developing  more  efficiency 
in  the  tube.  It  is  step 
twelve,  otherwise  known  as 
the  aging  process.  1  n  it  the 
tubes  are  placed  upright, 
several  hundred  at  a  time, 
on  a  table,  with  their  leads 
connected  to  circuits  which 
are  slightly  stronger  in  volt- 
age than  the  tube  is  subject- 
ed to  in  normal  use  (photo 
p.  397).  The  tubes  are  kept 
on  this  table  one  hour  to  see 
if  any  faults  develop  and  to 
obtain  the  maximum  elec- 
tron emission  from  the  fila- 
ment. During  this  aging 
test,  sometimes  the  degree 
of  vacuum  is  found  to  be 
insufficient.  This  condition 
can  be  determined  by  a 
measurement  of  the  nega- 


fig.  9 

Exhausting  the  tube — step  ten.  Ten  tubes  are  exhausted  simultaneously  in  this 
machine.  Each  one  is  surrounded  by  a  coil,  described  in  the  article,  and  its 
glass  stem  is  attached  to  a  rubber  tube  (seen  underneath  the  shelf)  which  leads  to 
the  pumps.  The  white  box-like  affair  just  above  the  row  of  tubes  is  the  oven.  It 
is  pulled  down  over  the  tubes  to  bake  them  as  a  part  of  the  exhausting  process 


How  Vacuum  Tubes  are  Made 


403 


plate,  grid  and  filament,  girls  do  the  task.  They 
do,  also,  most  of  the  preliminary  tests.  Men 
operate  the  exhausting  machines  and  do  the 
final  testing. 

A  visit  to  the  vacuum-tube  department  at 
East  Pittsburgh  is  a  revelation  of  the  efficiency 
of  the  workers.  The  recruits  are  trained  by 
skilled  operators  a  number  of  weeks  before 
they  are  placed  at  the  task  of  doing  the  actual 
assembling.  Some  difficulty  is  experienced  in 
obtaining  girls  who  are  dexterous  enough  to  do 
the  work  properly.  The  employment  depart- 
ment thinks  that  if  one  girl  out  of  ten  or  fifteen 
sent  to  it  is  found  satisfactory,  it  is  doing  well. 
All  these  things  must  be  considered  in  the  as- 
sembling process.  The  skill  of  the  worker  is 
largely  responsible  for  the  efficiency  of  the 
tube. 

Dry-cell  tubes  have  been  brought  to  a  high 
point  of  efficiency,  and  experiments  are  con- 
stantly being  carried  on  to  develop  this  effi- 
ciency further.  The  point  now  has  been 
reached  where  it  costs  much  less  to  operate 
the  filament  of  a  vacuum  tube  than  it  does 
to  light  the  electric  lamp  above  the  head  of 
the  radio  enthusiast  operating  his  receiver. 


Each  tube  is  a 
monument  to  mas- 
terful research,  in- 
ventive genius,  the 
wizardry  of  modern 
machinery  and  a 
perfect  organiza- 
tion of  workers  and 
officials. 

It  is  certain  that 
further  experiments 
now  going  on  will 
reduce  this  operat- 
ing cost  and  still 
further  lengthen 
the  life  of  the  dry 
cell.  The  Research 
Laboratory  which 
first  developed  the 
tube  is  constantly 
working  on  various 
forms  of  low-volt- 
age tubes.  These 
stories,  however, 
must  wait  until  the 
tubes  are  perfected. 


fig.  10 

After  the  tube  has  been  ex- 
hausted and  the  glass  stem 
sealed  off,  it  resembles  the  com- 
pleted tube  except  that  it  has 
no  base 


FIG.    I  I 

"Lighting  out."  The  tube  is  placed  in  a  holder  leading  to  the  three  lights  in  series  with  the  grid,  plate,  and  filament. 
If  one  of  the  lamps  lights  when  a  tube  is  placed  in  the  holder,  the  operator  knows  that  the  tube  has  developed  a  short 

circuit 


Some  Notes  on  Tuned  Circuits 


Inductance  and  Capacity— The  Two  Factors  that  Affect  the  Wavelength  of  Any  Circuit 

By  M.  B.  SLEEPER 


A  FTER  all  the  years  that  we  have  had 
radio  experimenters,  there  are  still 

/  \  inquiries  pouring  in  concerning  the 
%  wavelength  of  a  coil  or  a  variometer. 
Strangely  enough,  in  spite  of  the 
great  importance  of  tuned  circuits,  compara- 
tively little  has  been  written  to  give  the  sort  of 
detailed  explanation  of  them  that  have  been 
given  for  vacuum  tubes  and  various  other 
phases  of  radio  equipment  and  circuits. 

In  order  to  have  the  right  idea  about  wave- 
length and  tuned  circuits  you  must  first  realize 
that  a  coil  has  no  inherent  wavelength  other 
than  its  natural  period — a  useless  factor  in 
tuning.  It  would  be  just  as  incorrect  to  talk 
about  the  wavelength  of  a  variable  condenser 
as  of  a  coil  or  variometer,  for  wavelength 
depends  upon  inductance  and  capacity.  You 
would  not  speak  of  the  area  of  a  length.  You 
think  of  area  as  depending  upon  length  and 
width.  In  the  same  way  wavelength  is  deter- 
mined by  the  amount  of  inductance  of  a  coil 
and  the  capacity  of  a  condenser. 

Perhaps  one  of  the  reasons  for  this  confusion 
is  that  the  nature  of  the  capacity  in  a  tuned 
circuit  is  not  always  apparent.  Consider  the 
circuit  in  Fig.  i ,  that  of  an  ordinary  loose- 
coupled  set.  It  is  divided  into  a  primary  or 
antenna  circuit  and  a  secondary  circuit.  You 
might  think  off-hand  that  there  is  only  the 
inductance  of  the  coil  in  the  antenna  circuit. 


^PRIMARY 


SECONDARY  . 
-L  1    +6  A  ® — ®  B  6+ 


FIG.  I 

The  antenna-to-ground  circuit  in  any  re- 
ceiver provides  capacity  as  well  as  inductance 


Actually,  the  antenna  provides  the  capacity, 
because,  just  as  you  have  in  the  secondary  cir- 
cuit a  coil  connected  to  the  two  sets  of  plates 
of  a  condenser,  so  in  the  primary  you  have  the 
upper  end  of  the  coil  going  to  wires  strung  over 
the  ground,  and  at  the  other  end  a  lead  to  the 
earth.  The  antenna  wires  and  the  ground 
serve  as  condenser  plates  and  the  air  separating 
them  as  the  dielectric.  Therefore,  the  wave- 
length of  the  primary  circuit  is  not  determined 
merely  by  the  inductance  of  the  coil,  but  by 
that  inductance  and  also  the  capacity  of  the 
antenna-ground  condenser. 

If,  then,  you  use  the  primary  coil  of  an 
ordinary  variocoupler  in  the  antenna  circuit 
and  your  antenna  is  very  small,  perhaps  a  single 
50-foot  wire,  the  antenna-ground  capacity  will 
be  very  small  and  the  wavelength  correspon- 
dingly short.  When  you  increase  the  antenna 
to  one  of  four  wires,  each  100  ft.  long,  the 
capacity  will  be  much  increased,  and,  as  a  re- 
sult, the  wavelength  in  the  primary  circuit  will 
be  greater  than  before. 

Frequently  experimenters  complain  that 
they  cannot  tune  down  to  the  200-meter  sta- 
tions. Investigation  usually  shows  either  that 
the  antenna  is  too  large  or  the  minimum  tap 
on  the  coil  gives  an  inductance  so  great  that  the 
wavelength  at  the  lowest  is  above  200  meters. 

The  antenna  tuning  is  not  so  important  as 
the  tuning  of  the  secondary  circuit,  for  the  rea- 
son that  the  resistance  of  the  antenna,  the 
ground  lead-in,  and  the  ground  connection  is 
very  high,  and  consequently  tuning  is  not 
very  sharp  in  the  antenna  circuit. 

New  types  of  receiving  equipment  for  wave- 
lengths from  1  50  to  1000  meters  are  often  made 
with  untuned  primaries.  This  is  entirely 
practical,  unless  the  antenna  is  so  large  that 
its  capacity  and  the  inductance  of  the  lead-in 
and  ground  connection  is  sufficient  to  give  a 
wavelength,  regardless  of  the  inductance  of  the 
tuning  coil,  very  much  above  the  minimum 
wavelength  to  be  received.  A  loose  coupler, 
or,  as  it  is  more  often  called,  a  fixed  coupler, 
with  a  non-adjustable  primary  winding  relies 
largely  upon  shock  excitation  of  the  secondary 


Some  Notes  on  Tuned  Circuits 


405 


+®  A  ®-     -®  B  ©+ 


FIG.  2 

Capacity  in  the  secondary  circuit  is  supplied  by  the 
elements  of  the  tube  and  by  the  coils  themselves 

rather  than  on  tuning  the  primary  to  the  exact 
wavelength  of  the  incoming  signals. 

One  method  of  reducing  the  wavelength  in 
the  antenna  circuit  is  to  connect  a  variable  or 
fixed  condenser  in  series  with  the  lead  from  the 
antenna  to  the  coil,  or  from  the  coil  to  the 
ground.  This  reduces  the  wavelength  because 
the  total  capacity  of  two  condensers  in  series, 
in  this  case  the  antenna-ground  condenser  and 
the  condenser  in  the  set  decreases  the  total 
capacity  of  the  circuit.  On  the  other  hand,  the 
wavelength  can  be  increased  by  shunting  a 
condenser  around  the  coil,  for  it  is  then  in 
parallel  with  the  antenna-ground  capacity. 
Two  condensers  in  parallel  give  a  total  capacity 
equal  to  the  sum  of  the  two. 

The  secondary  circuit  is  quite  simple  in  an 
outfit  such  as  that  shown  in  Fig.  1.  The 
wavelength  is  determined  simply  by  the  in- 
ductance of  the  coil  and  the  capacity  of  the 
condenser.  Sometimes  a  fixed  inductance  is 
employed  with  a  variable  condenser;  or  the  coil 
is  tapped  so  that  the  number  of  turns  in  the 
circuit,  and  correspondingly  the  inductance, 
can  be  varied. 

The  absurdity  of  saying  that  the  coil  is  a  300- 
meter  inductance  is  evident  from  the  fact  that 
the  wavelength  of  the  circuit  varies  according 
to  the  adjustment  of  the  condenser.  Tables 
are  available  for  determining  the  wavelength 
of  any  circuit  according  to  the  inductance  of  the 
coil  and  the  particular  setting  of  the  condenser. 
If  honeycomb  coils  are  used,  the  wavelength 
can  be  found  from  tables  or  charts  supplied  by 
the  manufacturers. 

It  should  be  noted  that,  in  any  circuit,  the 
wavelength  does  not  change  in  direct  propor- 
tion to  the  inductance  or  capacity,  but  accord- 
ing to  the  square  root  of  either  factor.  In 


other  words,  if  the  condenser  capacity  is  in- 
creased four  times,  the  wavelength  is  only 
doubled.  A  very  simple  formula  gives  the 
exact  wavelength:  X  =  59.6\/LC>  where  X  is 
the  wavelength  in  meters,  L  is  the  induct- 
ance in  centimeters,  and  C  the  capacity  in 
microfarads.  Remember  that  one  million  cen- 
timeters is  equal  to  one  millihenry  of  in- 
ductance. 

Fig.  2  is  rather  puzzling.  It  shows  the  cir- 
cuit of  the  familiar  two-variometer  receiving 
set.  At  first,  you  might  say  that  there  is  no 
capacity  in  the  secondary  circuit,  but  only  the 
inductance  of  the  coil  in  the  variocoupler  and 
the  inductance  of  the  grid  variometer.  There 
is  capacity,  however,  for  the  grid  of  the  tube 
acts  as  one  plate  of  a  very  small  condenser  and 
the  filament  and  plate  of  the  tube  serve  as  the 
other .  plate,  not  to  mention  the  distributed 
capacity  found  between  adjacent  turns  of  the 
coils  themselves.  For  that  reason  a  much 
higher  inductance  is  required  than  would  be 
needed  if  the  circuits  were  tuned  by  a  variable 
condenser. 

Often  the  question  is  asked  whether  or  not 
the  plate  circuit  is  tuned  also  to  the  wavelength 
of  the  incoming  signals.  It  is  not  necessary  to 
do  this,  for  the  plate  variometer  gives  only  an 
approximate  adjustment. 

Some  manufacturers  have  attempted  to  rate 
their  variometers  for  wavelength,  and  in  that 
way  have  encouraged  experimenters  to  think  of 
the  wavelength  ranges  of  variometers.  This  is 
a  misleading  practice,  for  the  wavelength  is  con- 
siderably altered  by  the  size  of  the  secondaries 
used  in  different  types  of  variocouplers.  More- 
over the  capacity  of  vacuum  tubes  varies  con- 
siderably, the  capacity  of  the  UV-199  being  very 


-4  B  6+ 


FIG.  3 

This  single-circuit  hook-up  depends  upon  the  an- 
tenna capacity,  inductance  of  the  coil,  and  capac- 
ity of  the  tuning  condenser  for  its  wavelength 


406 


Radio  Broadcast 


low  and  of  the  U  V-20 1  -A  or  VT- 1  comparatively 
high.  However,  a  manufacturer  can  say  that 
his  variometer,  when  used  with  a  particular 
type  of  variocoupler  and  vacuum  tube,  tunes 
over  a  certain  wavelength  range. 

If  the  antenna  capacity  is  specified,  the 
primary  circuit  can  also  be  rated  for  wave- 
length. That,  however,  is  not  a  very  useful 
rating  because  antenna  capacities  vary  greatly: 
they  are  not  determined  merely  by  the  dimen- 
sions of  the  wires.  Trees,  buildings  and  metal 
roofs  or  large  chimneys  increase  or  decrease  the 
capacity.  An  antenna  erected  over  dry  earth 
does  not  have  the  same  capacity  as  one 
stretched  over  moist  earth,  for  example. 

A  single-circuit  receiver,  such  as  the  one 
shown  in  Fig.  3,  depends  upon  the  antenna 
capacity,  the  inductance  of  the  coil,  and  the 
capacity  of  the  tuning  condenser,  for  its  wave- 
length. Since  all  the  tuning  is  done  in  the 
antenna  circuit,  which,  as  explained  before, 
has  too  high  a  resistance  to  give  sharp  tuning, 
more  or  less  trouble  from  interference  is  often 


experienced.  You  will  find,  too,  that  the  setting 
of  the  plate  coupling  coil  or  plate  variometer 
will  affect  the  wavelength,  for  it  introduces 
another  value,  that  of  mutual  inductance  be- 
tween the  two  coils,  altering  the  effective  in- 
ductance in  the  circuit.  Thus,  altering  the 
antenna  circuit  requires  a  new  setting  of  the 
plate  variometer,  or  vice  versa  until  a  suitable 
balance  is  reached. 

If  you  want  to  design  your  equipment  ac- 
curately, you  must  measure  the  antenna  capa- 
city. This,  however,  is  not  at  all  necessary  in 
installing  or  operating  a  bought  receiver,  for 
most  of  that  work  has  been  done  for  you.  The 
method  is  simple,  and  details  of  the  process 
can  be  found  in  a  number  of  radio  books.  You 
will  need  to  find  out  as  much  as  you  can  about 
the  constants  of  your  coils  and  condensers  so 
that  you  can  determine  the  wavelength  range 
with  some  degree  of  accuracy.  In  any  caseJ  do 
not  go  by  wavelength  ratings  of  coils,  vario-coup- 
lers,  or  variometers,  and  above  all  do  not  learn 
to  think  of  inductance  in  terms  of  wavelength. 


A  Little  Foresight  and  a  Big  Success 

How  a  Knowledge  of  Radio,  Combined  with  Good  Business  Principles, 
Enabled  A.  J.  Haynes,  of  the  Haynes-Griffin  Radio  Service,  Inc.  to  Increase 
His  Business  a  Thousandfold  and  Give  Customers  Better  Values  and  Service 

By  ALFRED  M.  CADDELL 


WHEN  a  man  starts  in  busi- 
ness with  a  very  small  capital 
and  is  obliged  to  seek  larger 
store-space  twice  within  a 
year,  and  his  assets  increase 
a  thousandfold  during  the  same  period;  and 
especially  when  he  makes  his  money  on  your 
money — you  are  interested  in  him.  You  want 
to  learn  some  of  the  things  he  knows  about  the 
commercial  end  of  radio,  something  about  his 
business  methods  and  why  he  has  succeeded 
when  countless  others,  who  jumped  into  the 
business  with  both  feet,  have  failed. 

An  uphill  story,  or  a  story  that  starts  from 
scratch,  is  generally  a  good  one.  It  is  likely 
to  be  a  story  of  faith,  determination,  and  a  com- 
bination of  knowledge  and  good  will  toward 
the  business  itself.  Besides,  somewhere  in  the 
story,  may  lie  the  so-called  "secret"  of  success 
which  others  may  perceive — and  apply. 
Artemas  J.  Haynes  has  long  been  in  the  radio 


business,  either  as  an  amateur  purchasing 
equipment,  an  engineer  developing  new  appara- 
tus or,  as  at  present,  a  business  man  who  brings 
together  the  sources  of  supply  and  the  customer 
demand.  He  became  interested  in  radio  while 
a  student  in  preparatory  school  back  in  1910. 
Like  a  lot  of  amateurs,  he  commenced  with  a 
coherer — with  which  he  received  very  little. 
His  first  successful  receiving  set  was  an  indoor 
aerial,  crystal  detector  and  a  pair  of  75-ohm 
phones  through  which  he  could  hear  the 
local  high-power  spark  stations  and  occasion- 
ally a  ship. 

He  wasn't  very  different  from  the  average 
radio  amateur  of  those  days  and  now — 
every  odd  moment  out  of  school  and  college 
found  him  building  and  experimenting  with 
radio  apparatus.  He  had  sets  and  fragments 
of  sets,  mounted  high  on  a  table  and  strung 
around  his  room — batteries,  switches,  odd 
parts,  and  wire.    He  went  through  the  regular 


rv  Little  Foresight  and  a  Big  Success 


407 


MR.  HAYNES,   LIKE  PRESIDENT  HARDING,  DRIVES  A  TRACTOR  NOW  AND  THEN 


run  of  coherers,  magnetic,  crystal,  and  electro- 
lytic detectors,  tuning  coils,  loose  couplers,  and 
finally  ended  up  with  the  De  Forest  Audion,  a 
little  round  bulb  that  screwed  into  a  miniature 
socket,  with  a  small  square  plate  and  grid  and 
two  carbon  filaments — a  wonderfully  big 
feature  in  those  days. 

"We  were  all  a  bit  skeptical  of  that  little 
bulb  at  first,"  says  Mr.  Haynes.  "The  prom- 
ises made  for  it  sounded  too  good  to  be  true 
and  it  wasn't  until  after  much  hesitancy  that  I 
finally  purchased  one  and  compared  it  with  my 
prize  galena  crystal  that  I  realized  with  a  heart- 
felt sigh  that  my  interminable  search  for  the 
most  sensitive  spot  on  the  most  sensitive  crystal 
was  over." 

When  the  United  States  entered  the  World 
War  in  1917,  Mr.  Haynes  was  a  student  at  Yale 
University.  Immediately  after  the  declara- 
tion of  war  he  enlisted  in  the*  Naval  Reserve, 
and  was  among  the  first  to  attend  the  Brooklyn 
Navy  Yard  Radio  School.  Things  were  mov- 
ing fast  in  those  days,  and  new  orders  went 
flying  about,  so  he  quickly  found  himself 
assigned  as  radio  operator  to  the  U.  S.  Shu- 
brick,  a  hastily  converted  coal-burning  des- 
troyer that  was  pressed  into  service  for  patrol 
and  convoy  work.  Then  he  went  to  the  naval 
radio  station  at  New  Haven,  after  which  he  was 
suddenly  transferred  as  radio  instructor  to 


Yale  University,  where  he  taught  many  of  the 
boys  their  first  principles  of  radio. 

So  much  for  his  pre-business  days,  which  had 
proved  to  be  a  wonderful  combination  of  learn- 
ing and  teaching,  resulting  in  a  solid  founda- 
tion in  radio.  Now  came  employment  with 
the  De  Forest  Radio  Company  as  engineer,  a 
year  or  more  in  the  laboratory  and  then  a  posi- 
tion placing  him  in  charge  of  foreign  sales.  But 
in  the  early  part  of  1920,  when  radio  as  a  means 
of  livelihood  seemed  uncertain,  he  took  a  look 
into  the  retail  music  field.  Not  for  long,  how- 
ever. Indeed,  he  was  permitted  only  a  passing 
glance,  for  the  dawn  of  radio  broadcasting  ap- 
peared on  horizon  in  1920-21. 

"  I  think  most  of  us  who  had  followed  the 
business,"  said  Mr.  Haynes,  "realized  that 
sooner  or  later  radio  broadcasting  was  bound 
to  become  a  big  thing,  and  notwithstanding 
the  long,  almost  impatient  wait,  it  really  came 
much  quicker  than  I  expected.  As  it  was,  the 
suddenness  of  its  coming  found  me  in  the  woods 
of  Maine,  but  I  returned  to  New  York  as  soon 
as  I  could.  During  the  winter  of  1920-21  I 
operated  the  De  Forest  experimental  station  at 
Highbridge  (2XG)  which  was  used  primarily 
for  test  and  demonstration  work  between 
Highbridge  and  2XX,  our  other  experimental 
station,  operated  by  Robert  F.  Gowan  of 
honeycomb  coil  fame,  located  at  his  home  in 


4o8 


Radio  Broadcast 


Ossini-ng.  I  spent  many  evenings  at  old  2XG 
testing  with  amateur  stations  and  playing 
phonograph  records  to  entertain  listeners  in 
and  around  New  York.  In  fact,  we  staged  a 
good  many  dances  this  way  in  the  homes  of 
radio  amateurs  who  were  equipped  with  loud 
speakers. 

"And  then  the  big  broadcasting  storm  broke 
over  the  land.  Previously,  the  interest  in 
radio  had  been  comparable  to  the  few  drops  of 
rain  that  announce  a  cloudburst.  Hundreds 
of  wild  schemes  followed  in  the  aftermath.  It 
was  the  beginning  of  the  Radio  Age. 
Dealers  who  had  no  previous  experi- 
ence with  radio  or  electrical  equip- 
ment began  selling  radio  apparatus 
like  so  many  nuts  and  bolts.  Factories 
soon  lagged  far  behind  in  filling  their 
orders,  a  fact  which  led  dealers 
to  duplicate  their  requirements 
with  many  jobbers  and  manufac- 
turing concerns.  But  after  the  first  heat  of 
the  race,  the  public  called  a  halt  and  began 
analyzing  the  situation.  They  became  wary 
of  radio  sets  sold  over  the  books-and-station- 
ery  counters,  and  at  the  drug  store.  They  be- 
gan to  discriminate  between  the  cheaply  built 
apparatus  and  that  which  was  more  reliable. 
Meanwhile,  manufactures  had  been  led  to  in- 
crease their  production,  but  they  had  hardly 
begun  turning  out  the  rush  equipment  when  the 
buying  demand  fell  off.  The  lure  of  'money  in 
radio'  soon  showed  its  face — inexperienced 
dealers  who  had  placed  large  orders  for  cheap 
apparatus  found  themselves  loaded  with  stock 
which  suddenly  had  lost  half  its  retail  value. 
Exit  from  the  radio  business  seemed  to  many 
to  be  the  only  way  out  of  such  an  unprece- 
dented situation. 

"  Fortunately,  1  had  seen  a  lot  of  discourage- 
ment in  trying  to  get  radio  broadcasting 
started,  and  this  operated  to  make  me  proceed 
most  cautiously.  Would  the  present  flurry 
last?  I  saw  permanence  in  radio,  but  at  a 
distance.  As  the  public  now  knows,  the  radio 
business  was  encumbered  by  men  with  no 
knowledge  foundation  whatever,  who  like 
get-rich-quick  promoters  were  riding  on  the 
back  of  free  publicity.  How  to  avoid  the  pit- 
falls that  were  bound  to  react  from  such  a 
situation?  How  to  get  into  the  retail  business 
and  make  progress  at  the  same  time?  How 
to  make  it  known  that  1  had  the  technical  ex- 
perience, that  I  knew  radio  goods,  that  I  had  a 
desire  to  fit  the  customer's  pocketbook  and 


needs  together,  that  I  aimed  to  be  in  the  busi- 
ness to  stay  and  was  more  than  willing  to  co- 
operate with  customers  to  see  that  they  got 
the  very  best  out  of  their  outfits  to  which  they 
were  entitled? 

"Skimming  the  cream  off  milk  and  expect- 
ing that  milk  to  retain  its  full  value  presented 
an  altogether  incompatible  viewpoint.  There 
was  only  one  way  to  go  into  a  permanent  retail 
radio  business  and  that  was  to  take  counsel 
with  customers,  talk  frankly  to  them,  tell  them 
that  you  aimed  to  stay  and  grow  in  the  business 
and  offer  to  be  of  assistance  then  and 
thereafter.  Reconciling  the  situation 
as  best  I  could,  I  borrowed  a  little 
money  and  opened  up  a  small  store 
known  as  the  Haynes  Radio  Shop  on 
Lexington  Avenue,  New  York,  in  the  ' 
spring  of  1922. 

"At  first,  I  barely  paid  the  rent 
on  the  place  out  of  the  income  of 
the  business.  But  gradually  I  began  to 
get  more  customers — young  lads  who  were 
anxious  to  have  sets  installed  in  their  homes. 
I  hired  one  man,  then  two,  and  the  little 
business  began  to  look  up.  At  times  the 
gross  receipts  amounted  to  less  than  Si 00  a  day, 
which  barely  allowed  me  to  make  both  ends 
meet.  Then  it  commenced  a  steady  upward 
climb  as  the  summer  slump  of  1922  began  to 
draw  toward  its  end.  Private  installations  now 
became  more  in  demand,  one  job  attracting  an- 
other. When  Johnny  Smith  or  Bobby  Jones 
got  in  trouble,  if  I  couldn't  explain  it  away 
when  he  called  at  the  shop,  with  a  perplexed  look 
on  his  face,  1  went  over  to  his  place,  diagnosed 
the  ailment  and  set  his  apparatus  in  order. 
After  that,  it  very  seldom  got  out  of  order,  for 
he  was  getting  accustomed  to  it  and  mani- 
pulated it  only  in  the  way  he  should. 

"  During  this  baby  growth  of  the  business  I 
advertised  very  little,  for  the  simple  reason 
that  I  had  no  available  funds.  But  had  1  had 
extra  money  at  the  time  I  hardly  think  I  would 
have  plunged  into  the  business  any  heavier  just 
then.  Liquidation,  elimination,  controversy 
over  the  permanence  of  radio,  and  confusion 
were  in  the  air.  But  at  various  turns  radio 
broadcasting  gave  healthy  signs  of  surmounting 
its  troubles.  The  curve  on  the  chart  that  1 
kept  and  an  auditing  of  my  accounts  left  no 
doubt  about  this. 

"  During  radio's  inevitable  slump  in  the 
summer  of  1922,  I  was  one  of  the  organizers  of 
the  first  Radio  Dealers'  Association  of  New 


A  Little  Foresight  and  a  Big  Success 


409 


York,  and  served  as  Vice-President  as  long  as 
that  organization  lasted.  Mr.  Griffin,  now  my 
partner  in  the  firm  of  Haynes-Griffin  Radio 
Service,  Inc.,  was  President.  Personally,  I 
consider  the  greatest  benefit  derived  from  that 
association  was  the  bringing  of  Mr.  Griffin  and 
myself  together.  Mr.  Griffin's  whole  training 
and  experience  over  a  period  of  more  than  six 
years  had  been  in  advertising  and  merchandis- 
ing with  one  of  the  leading  advertising  organ- 
izations in  the  country.  He  brought  to  the 
organization  a  breadth  of  vision  and 
experience  which  most  retail  merchants 
acquire  only  after  years  of  hard  work 
and  hard  knocks.  This,  supported  by 
my  own  training  in  the  technical  side 
of  radio,  gave  the  new  organization 
a  combination  of  experience  seldom 
found  in  any  business  conducted 
solely  by  one  man  whose  training 
and  inclination  generally  lies  along  one  particu- 
lar line. 

"Mr.  Griffiin  had  been  in  the  radio  retail 
business  in  rather  a  small  way  by  himself.  But 
each  of  us  realized  that  we  had  progressed  as 
far  as  we  could  by  ourselves,  for  in  order  for 
either  one  of  us  to  take  care  of  any  more  business 
it  meant  increased  organization.  Besides,  our 
individual  locations  just  then  were  not  ideal 
for  expansion — we  felt  it  necessary  to  locate  in 
a  more  transient  section  of  the  city  which  of- 
fered greater  contact  with  the  radio  public." 

The  results  of  that  merger  speak  for  them- 
selves. The  two  young  business  men,  as 
partners,  began  to  forge  ahead  very  rapidly. 
Locating  midway  between  Times  Square  and 
the  Grand  Central  Terminal,  New  York,  a 
more  strategic  spot  for  transient  accommoda- 
tion could  not  be  had.  It  was  the  one  thing 
needed  to  assure  their  success.  Shortly  after 
the  partnership  was  effected,  the  opportunity 
came  to  purchase  the  Lexington  Radio  & 
Electric  Company,  and  not  only  the  stock  and 
good-will  of  that  company  was  taken  over  but 
the  entire  personnel  as  well.  This,  therefore, 
made  the  Haynes-Griffin  Radio  Service,  Inc. 
a  combination  of  three  of  the  oldest  and  best 
known  radio  stores  in  New  York  City,  and  the 
many  regular  customers  which  the  additional 
store  immediately  brought  to  the  combination 
helped  toward  the  great  expansion  which  has 
since  taken  place. 

But  before  this  article  appears  in  print,  Mr. 
Haynes  and  his  associates  will  have  given  even 
more  tangible  evidence  of  the  success  which 


has  followed  in  the  wake  of  their  business 
methods  and  ideals.  For  during  July  they 
opened  the  largest  radio  store  in  New  York 
City,  which  probably  also  means  the  largest  in 
the  world.  Space  and  facilities  are  more  than 
tripled  in  the  new  store.  More  than  4,000 
square  feet  are  devoted  to  the  sale  of  radio 
apparatus  alone.  In  this  store  are  incor- 
porated several  new  ideas  in  the  merchandising 
of  radio.  On  the  ground  floor  where  parts 
and  accessories  are  carried  there  are  in 
effect,  three  radio  stores  in  one.  For 
the  stock  of  the  store  is  duplicated 
in  three  different  locations  so  that 
customers  may  be  served  efficiently 
and  quickly  without  either  salesmen 
or  customers  being  obliged  to  move 
about  from  counter  to  counter  in 
order  to  secure  everything  that 
may  be  desired.  On  the  second 
floor  there  are  several  small  sound-proof 
demonstration  booths  similar  to  those  in 
phonograph  shops,  where  practically  every 
make  of  proven,  well-known  radio  receiver  is 
on  display;  while  in  the  basement  will  be 
located  a  repair  and  service  department  which, 
from  an  adjunct  of  the  radio  retail  business, 
has  grown  to  be  a  department  of  the  first 
importance. 

Many  stories  of  how  service  and  attention 
resulted  in  further  business  abound  about  the 
shop.  A  short  time  ago  a  man  from  Connecti- 
cut came  into  the  store  to  buy  an  insulator  for  a 
receiving  antenna.  He  had  been  sent  in  by  his 
employer  who  thought  what  he  wanted  was  a 
very  large  insulator.  However,  he  was  as- 
sured that  a  midget  insulator  costing  twenty- 
five  cents  would  do  as  well,  and  reassured  that 
if  it  proved  unsatisfactory  to  his  employer  the 
twenty-five  cents  would  be  refunded  and  a 
larger  insulator  substituted  in  its  place. 
Furthermore,  the  salesman  obtained  the  em- 
ployer's name  and  saw  to  it  that  a  letter  was 
written  to  him  that  night,  explaining  to  the 
employer  why  his  man  had  been  persuaded  to 
take  the  midget  insulator.  The  result  of  this 
attention  to  such  a  small  purchase  is  almost 
unbelievable — since  then  the  employer,  al- 
though he  has  never  been  inside  the  store  and 
is  not  personally  aquainted  with  the  organiza- 
tion has  bought  more  than  $3,000  worth  of 
radio  merchandise. 

Another  instance  was  that  of  a  young  office 
man  in  Brooklyn  who  bought  a  "Haynes  Cir- 
cuit" receiving  set,  the  development  of  Mr. 


Radio  Broadcast 


Haynes.  He  knew  little  or  nothing  about  the 
radio  art,  and  was  obliged  to  come  into  the  store 
on  several  occasions  to  get  pointers.  As  a  re- 
sult of  the  attention  given  him,  he  has  been  in- 
strumental in  selling  thirty-six  sets  to  fellow 
office  workers  and  officials  in  the  company 
where  he  was  employed.  All  of  them  were 
"  Haynes  Circuits." 

A  case  of  a  somewhat  different  type  may  also 
be  cited.  A  woman  came  into  the  shop,  saying 
that  a  friend  was  going  to  sing  that  evening  at 
one  of  the  broadcasting  stations,  and  she  had 
been  given  to  understand  that  if  she 
came  to  the  shop  she  could  hear  her 
sing.  Just  how,  she  knew  not,  but 
that's  what  she  had  been  told.  Would 
they  be  open  that  evening?  Ordinarily 
they  would  not,  yet  this  time  most 
assuredly  they  would.  More  than 
that,  they  invited  the  woman  to 
ask  all  her  friends — the  shop  would 
be  a  regular  receiving  station  that  evening. 
Eight  women  came,  and  listened  throughout 
the  whole  performance,  and  eight  women  had 
the  mysterious  something  explained  to  them — 
that  is,  explained  so  that  they  felt  confident 
they  could  hear  the  same  kind  of  music  in  their 
own  homes.  And  so  eight  more  enthusiasts, 
soon  to  become  customers,  were  introduced  into 
the  radio  fold  that  evening. 

"  1  consider  that  1  sell  good-will  and  service 
more  than  radio  equipment,"  says  Mr.  Haynes. 
"And  1  think  you  will  find  this  to  be  the  case 
with  every  successful  dealer  in  the  radio  field. 
Radio  is  such  a  large  proposition  and  so  en- 
tirely new  to  most  people — a  scientific  thing 
made  popular — that  real  merchandising  con- 
sists of  individual  education.  In  the  begin- 
ning, both  dealer  and  customer  were  like  two 
strangers  who  spoke  a  strange  tongue  in  a 
strange  land.  They  understood  each  other 
very  little.  Unlike  the  clothing  business, 
for  example,  which  is  as  old  as  man  himself, 
radio  burst  upon  the  world  as  a  brand  new 
creation.  Customers  knew  so  little  about  it 
that  they  wonderingly  asked:  'How  much  do 
you  charge  for  an  ohm?'  and  things  like  that. 
You  couldn't  laugh  at  them — you  simply  had 
to  explain  what  an  ohm  was. 

"  It  was  due  to  this  prevailing  lack  of  knowl- 
edge that  many  customers  were  victimized  by 
unscrupulous  dealers  who  probably  didn't 
know  much  more  themselves  but  who  sold  them 
anything  in  order  to  get  their  money.    But  it 


was  also  due  to  this  lack  of  knowledge  that  we 
owe  our  success.  It  was  a  wonderful  chance  to 
gain  a  customer's  confidence.  Each  customer, 
of  course,  presented  an  individual  problem,  but 
we  have  yet  to  meet  the  problem  in  the  cus- 
tomer line  that  we  have  not  been  able  to  solve. 
The  sales  we  have  lost  by  being — as  some  might 
consider  it — too  frank  in  our  advice,  have  been 
more  than  made  up  in  almost  every  case  by  the 
confidence  and  ultimate  business  we  have  en- 
joyed from  those  same  customers.  So  much  has 
been  written  about  the  'straight  and  narrow' 
way  of  doing  business  that  I  am  afraid 
the  eye  slides  right overitwithout  ever 
seeing — at  least  not  focussing  atten- 
tion on  it  sufficiently  long.  But  of 
this  I  am  sure:  that  the  radio  retail 
dealer  who  sells  service  and  atten- 
tion first  and  equipment  afterward 
will  have  a  larger  credit  balance  at 
the  end  of  the  year  than  the  dealer 
who  sells  equipment  only." 

The  speaker  led  the  way  to  the  rear  of  his 
shop,  opened  a  locker  door,  picked  out  his  ten- 
nis racket,  and  prepared  to  "call  it  a  day." 
Tennis  is  one  of  his  standby  recreations,  and 
one  can  see  the  effects  of  it  in  his  eye  and  step. 
Next  comes  swimming,  and  sport  with  the 
rod  and  gun.  As  is  evidenced  by  the  healthy 
state  of  equilibrium  in  which  he  keeps  himself, 
he  knows  how  to  mix  pleasure  with  business 
and  not  keep  himself  too  near  the  saturation 
point.  Besides,  his  wife  won't  let  him  become 
over-concerned  with  his  hobby,  even  though 
it  is  the  radio  business. 

Like  many  others  in  the  commercial  field 
who  have  kept  their  ears  close  to  the  ground 
and  their  eyes  on  the  progress  of  radio,  both 
Mr.  Haynes  and  Mr.  Griffin  maintain  that  the 
possibilities  of  the  art,  especially  in  the  way  of 
a  quickening  of  intelligence  in  all  classes  of 
people,  are  only  beginning  to  be  realized.  The 
biggest  thing,  of  course,  is  the  proper  control 
of  broadcasting.  As  one  who  has  seen  the 
broadcasting  art  develop  from  "Station  2XG, 
calling — 1,  2,  3,  4;  Station  2XG  calling — 1,  2,  3 
4"  to  the  present  high  state  of  efficiency,  Mr. 
Haynes  has  confidence  that  broadcasting  will 
develop  equally  as  much  again;  that  the  day 
will  come  when  broadcasting  will  be  subsidized 
by  the  government  for  the  unlimited  use  of 
everybody — not  a  local  or  state  affair,  but  na- 
tional, as  an  investment  in  education,  recrea- 
tion, and  good  citizenship. 


ELLIOTT  JENKINS  (LEFT)  AND  THORNE  DONNELLEY  (RIGHT)  TESTING  THEIR  WRIGLEY  TOWER  OUTFIT 


Highlights  in  the  History  of  WDAP 

The  Chicago  Broadcasting  Station  that  Plays  Dance  Music  for  Half  a  Continent 
By  J.  ELLIOTT  JENKINS 


CANNOT  make  up  my  mind  whether 
this  brief  history  of  WDAP,  which  I  am 
writing  at  the  request  of  the  Editor  of 
Radio  Broadcast,  will  be  a  confession  or  a 
biography.  However,  it  should  be  some- 
what amusing,  especially  to  those  familiar  with 
broadcasting  stations.    It  certainly  is  to  me. 

Thorne  Donnelley  and  I,  though  we  had 
never  worked  together  before,  had  been  per- 
fectly good  hams  in  the  days  of  Morse  and 
carborundum,  when  you  used  part  of  your 
father's  automobile  for  your  transmitter,  and 
your  initials  were  your  call.  My  early  training 
in  the  art  of  making  the  cook's  favorite  rolling 
pin  into  a  tuning  inductance  came  from  Paul 
Godley,  then  an  operator  on  the  Great  Lakes. 
But  in  1 92 1,  when  the  Local  Westinghouse 
station  first  opened  up  with  the  Chicago  Opera, 
the  trouble  began.  Donnelley  came  up  to  my 
house  one  evening  to  consider  a  Morehead 


tube  hooked  to  a  loose  coupler  tuner.  Strains 
of  Aida  were  faintly  audible.  This  was  too 
much.  The  following  week,  I  was  summoned 
to  his  house,  where  he  had  collected  most  of 
the  receiving  apparatus  in  Chicago.  It  covered 
the  floor  and  the  grand  piano,  and  a  certain 
amount  of  it  would  function.  A  few  days 
later  came  a  hurry  call  on  the  arrival  of  a 
20-watt  Paragon  transmitter.  This  gave  room 
for  a  lot  of  thought. 

A  few  days  later,  riding  past  the  Wrigley 
Tower  on  Michigan  Avenue,  I  said  1  thought 
it  would  make  a  good  place  for  an  experimental 
laboratory.  About  a  week  later,  Donnelley 
came  bursting  into  my  own  laboratory  on  Van 
Buren  Street,  followed  by  three  men,  two  boys, 
and  several  dozen  boxes.  I  said,  "What's 
this?"  and  he  replied,  "Our  broadcasting  sta- 
tion for  the  Wrigley  Building.  I'm  going 
over  there  now  and  string  the  antenna  while 


412 


Radio  Broadcast 


you  put  this  stuff  together."  He  shoved  some 
papers  at  me,  original  art  drawings  by  Charlie 
Logwood,  then  in  Chicago,  of  a  ioo-watt,  grid- 
modulated  oscillator,  and  I  went  at  it. 

In  about  a  week  the  thing  was  up,  perched  in 
the  penthouse  among  huge  water  tanks  and 
steel  pipes.  It  led  into  a  sort  of  cage  antenna 
which  hung  at  an  angle  to  the  tower.  It 
radiated  four  amperes  and  sounded  like  nothing 
the  air  had  ever  heard  before.  We  worked  it 
as  9CT  for  a  while,  and  then  our  broadcasting 
license  arrived.  This  necessitated  a  studio. 
A  dear  friend  of  ours  was  experimenting  with 
the  advertising  business  on  the  floor  below,  so 
we  appropriated  the  front  half  of  the  office  and 
moved  in  a  piano  and  a  few  yards  of  drapery. 
We  overcame  the  microphone  problem  by 


THE  STATION  IN  THE  WRIGLEY  TOWER 
Showing  generators,  inductances,  "hay  wire,"  etc. 


packing  a  four-button  carbon  affair  into  a 
fibre  waste  basket  and  hanging  it  on  a  pale 
blue  parrot-cage  support.  I  shall  never  forget 
the  general  effect.  On  top  of  the  piano  sat  a 
loud  speaker,  connected  to  a  hand  microphone 
in  the  operating  room.  When  the  operator — 
it  required  just  one  to  run  the  transmitter  and 
the  concert — would  announce  the  station  and 
the  next  number,  .it  would  be  fairly  audible 
to  those  in  the  studio.  Then  he  would  turn 
and  bellow — "All  right,  shootl"  and  the  tem- 
peramental talent  below  would  recover  as  rap- 
idly as  possible  and  do  its  best  at  the  waste 
basket.  It  was  a  great  way  to  run  a  station, 
and  I  wish  we  could  return  to  it. 

"WDAP,  located  on  the  Wrigley  Building, 
Chicago,  Illinois  (it's  a  wonder  we  left  off  the 
U.  S.  A.),  ground  out  her  closing  quotations 
and  her  three  concerts  a  week  all  through  the 
winter  and  up  to  July,  1922,  steadily  growing 
worse.  It  is  a  curious  thing,  that  process  of 
natural  decay  which  a  station,  put  up  by  the 
inexperienced,  always  undergoes.  It  just  gets 
worse,  despite  your  increasing  knowledge  and 
your  violent  efforts,  and  nothing  will  save  it. 
So  one  afternoon  in  late  July,  a  fortunate  thing 
occurred.  The  sky  turned  a  peculiar  green, 
lightning  flashed,  and  windows  in  the  "Loop" 
blew  in.  A  moment  later  the  sun  shone.  With 
mingled  feelings  I  drove  to  the  Wrigley  Build- 
ing. It  had  a  curious  bare  appearance  in  the 
sunshine.  Pieces  of  our  antenna  were  picked 
up  in  all  directions  for  weeks.  As  I  remember, 
we  had  used  acid  flux  when  putting  it  up 
originally. 

But  sometime  before  this,  Donnelley  and  1 
had  realized  that  it  is  almost  impossible  to  put 
up  a  decent  antenna  on  a  tower-like  building, 
so  we  began  making  overtures  to  the  Drakes, 
deeply  affected  by  thoughts  of  the  reinforced 
concrete  understructure  the  deep  courts,  and 
the  sixty-foot  steel  masts  on  the  corners  of  the 
roof.  One  of  the  directors  of  the  Whitestone 
Company,  which  operates  the  Drake  Hotel, 
had  unfortunately  heard  the  old  station,  but 
the  idea  went  over  regardless.  So  immediately 
after  the  windstorm,  we  moved  an  astounding 
collection  of  junk  into  the  two  handball  courts 
and  dressing  room  on  top  of  the  Drake.  These 
were  not  . in  much  demand,  and  would  make 
marvelous  studios  and  transmitter  room. 
The  dressing-room  faced  the  south  court,  so 
we  set  the  old  ioo-watt  job  up  there  and  with 
tremendous  effort  strung  a  huge  T  antenna 
between  the  southeast  and  southwest  flag  masts. 


Sixty  feet  under  it  we  rigged  a  fan  counterpoise. 
This  was  a  success  from  the  start.  One  ampere 
sent  into  it  would  raise  the  dead. 

In  the  meantime  I  had  been  working  as  I 
never  intend  to  again,  building  a  one-kilowatt 
set.  This  was  of  the  power  amplifier  type  for 
the  simple  reason  that  it  cost  just  half  as  much 
as  the  usual  type  of  large  transmitter  for  the 
given  rated  output,  using  half  as  many  tubes 
and  half  as  much  current.  It  had  a  50-watt 
grid  modulated  driver  and  room  for  four 
J-KW  tubes.  Excepting  our  good  friend  E.  K. 
Oxner,  Donnelley  and  I  were  our  own  authori- 
ties on  large  power  amplifiers,  so  when  the  new 
transmitter  simply  refused  to  work,  we  could 
go  nowhere  for  help.  After  a  three  weeks' 
struggle,  we  gave  a  Sunday  night  concert  with 
three  amperes  in  the  antenna.  People  in  town 
phoned  us  to  shut  the  rotten  thing  off,  but  a 
few  crystal  set  owners  called  up  wild  with 
enthusiasm.  They  were  hearing  us  without 
their  antennas,  and  our  modulation  was  per- 
fect. For  the  next  three  days  the  mail  rolled 
in,  coming  from  everywhere  but  the  West 


Coast.  It  seems  that  our  small  output  was 
so  concentrated  on  just  one  wavelength  that 
all  tube  sets  within  twenty  miles  began  to  back- 
fire when  tuned  to  it.  For  some  time  after 
that,  listeners  with  tube  sets  anywhere  near  us 
found  it  necessary  to  turn  their  tube  filaments 
way  down  to  get  us  properly. 

We  felt  that  we  had  something  unusual,  and 
went  to  work  hard  on  the  set,  adding  tubes  and 
working  up  the  radiation,  half  an  ampere  at  a 
time.  Finally  the  West  Coast  mail  began  to 
come  in.  It  was  a  nightly  occurrence  to  have 
listeners  in  the  Eastern  states  get  excited  and 
call  us  on  the  phone,  relaying  our  signals  back 
to  us  over  the  land  line.  I  recall  one  night 
when  I  was  particularly  impressed  with  the 
speed  of  ether  wave  transmission.  I  was  at 
the  transmitter,  and  the  doors  to  the  studio 
were  open.  A  gentleman  in  Seabright,  N.  J. 
called  us  up  and  I  took  the  call.  He  compli- 
mented us  on  the  station  and  put  one  of  his 
headphones  to  the  telephone  mouthpiece. 
The  notes  of  the  piano  number  in  progress 
went  through  our  broadcasting  microphone  and 


4i4 


Radio  Broadcast 


THE  FIRST  TRANSMITTER  AT  THE  DRAKE  HOTEL 
It  got  its  concerts  as  rar  as  Surrey,  England,  Rio  de  Janeiro,  Wrangel,  Alaska,  and  to  a  ship  300  miles  this  side  of  Honolulu 


the  set  to  Seabright,  and  back  to  my  left  ear 
over  the  wires  so  much  more  quickly  than  they 
came  through  the  air  from  the  studio  to  my 
right  ear  that  the  difference  was  easily  notice- 
able. In  one  case  they  traveled  1,800  miles; 
in  the  other,  40  feet. 

I  will  never  forget  the  first  night  we  broad- 
casted Jack  Chapman's  orchestra.  Our  lines 
to  the  main  floor  had  just  been  installed,  and  I 
went  down  with  a  microphone  and  put  it  on 
Jack's  piano.  When  1  got  back  to  the  trans- 
mitter room  1  found  Donnelley  and  the  first 
operator  dancing  violently  around  the  place 
dragging  a  crystal  monitoring  set  after  them. 
Apparently  everyone  listening  felt  the  same 
way,  as  our  mail  went  from  200  to  around  800 
letters  a  day. 

WDAP  went  off  the  air  recently  for  sev- 
eral weeks,  and  all  hands  turned  to  for  the 
completion  of  the  new  transmitter.  This  takes 
up  the  entire  other  handball  court  on  the  floor. 
It  is  in  the  form  of  a  single  unit  of  two-inch 


piping  and  condulet  work.  All  the  generators 
are  at  one  end.  Then  come  the  filter  systems, 
input  control  panels,  circuit  breakers,  and  field 
rheostats.  There  are  three  transmitter  cases 
in  a  row,  the  middle  one  containing  a  hundred- 
watt  driver  circuit.  This  may  be  coupled  to 
either  of  the  outside  cabinets,  which  contain 
separate  power  amplifiers.  In  front  of  all  this 
is  the  operating  desk,  with  remote  controls  for 
everything  and  microphone  lines.  Way  up 
above  the  structure  are  the  tuning  variometers, 
of  I  inch  copper  tubing.  The  lead-in  comes 
through  the  skylight  for  an  antenna  of  four  long 
cages  in  the  form  of  an  X.  Under  the  antenna 
is  a  vast  counterpoise  covering  the  entire  roof 
of  the  hotel. 

We  went  on  the  air  with  the  new  station 
Saturday,  June  29th,  1923.  We  have  great 
hopes  for  it,  and  letters  received  thus  far  in- 
dicate that  the  two  years  of  hard  work  we 
have  spent  on  power  amplifiers  was  more  than 
justified. 


"Music 
Hath 
Charms — 


BUT  NOT  TO  SOOTHE  THE 
TOO-SAVAGE  BREAST 
Of  this  royal  prisoner  at  the  Bronx 
Zoological  Park,  in  New  York.  When 
music  from  a  broadcasting  station  was 
turned  on,  Chief  Keeper  John  Toomey 
was  glad  he  was  on  the  outside,  looking 
in.  Not  all  the  animals  lacked  the 
musical  appreciation  of  this  lion  how- 
ever 


(right)  "grandpa"  felt  600 
years  younger 

And  seemed  decidedly  pleased  with  the 
radio  music.  It  is  estimated  that 
"Grandpa"  celebrated  his  269th  birth- 
day about  the  year  Columbus  came  over 


Receiving  Contest 
Winners 


Infinite  Painstaking,  Excellent  Workmanship  and  Great 
Originality  Evidenced  by  the  Successful  Contestants. 
Miss  White  Wins  Third  Place.  Three  Complete  Articles 
by  the  Winners.  Next  Month  Will  Appear  Much 
"Dope"  and  Many  Interesting  Illustrations  from  Other 
Entrants— also  "Honorable  Mentions"  and  Summary 


'AST  month   we   published   the  winning 


article  in  the  long-distance  receiving 


TAST 

contest  "  held  to  determine  who  has 
.  done  the  best  with  any  number  of 
tubes  and  any   type  of  receiver." 
This  month,  we  announce  the  winners  of  the 
second,  third,  and  fourth  prizes,  and  print 
their  articles  in  full. 

The  great  pile  of  manuscripts,  photos, 
diagrams,  etc.,  that  flooded  the  editorial  office 
of  Radio  Broadcast  has  been  very  carefully 
gone  over  during  the  last  four  weeks,  and  a 
rich  mine  of  data  has  resulted,  which,  we  are 
sure,  is  going  to  help  many  an  enthusiast  to 
solve  his  own  radio  difficulties  and  to  build 
his  own  apparatus  more  effectively- 
Some  of  you,  unfortunately,  fell  down  on  one 
or  more  of  the  requirements — omitted  photos, 
for  instance,  or  neglected  to  include  adequate 
data  on  the  construction  and  operation  of  your 
sets.  It  was  stated  in  the  Rules  of  the  Contest, 
that  "  manuscripts  should  include  the  following: 
description  of  set,  directions  or  advice  for  con- 
structing and  operating  it;  any  'wrinkles'  or 
makeshifts  which  you  have  used  to  advantage; 
photograph  of  your  apparatus;  circuit  diagram; 
in  general,  anything  you  have  to  tell  that  will 
make  your  story  more  interesting  and  help- 
ful." Thus  in  judging  contributions,  "the 
quality  and  interest  of  photographs,  text,  and 
drawings,  and  the  originality  and  general  effec- 
tiveness of  the  apparatus  described"  had 
"greater  weight  than  the  list  of  stations  heard," 
although  a  long  list  of  distant  stations  dis- 
tinctly helped. 

The  contest  winners  and  the  prizes  they  have 
won  are  as  follows: 


FIRST 

Richard  Bartholomew,  of  Garrochales,  Porto 
Rico.  He  has  been  sent  the  first  prize,  a  De  Forest 
D-io,  4-tube  Reflex  Loop  Receiver.  (For  his  article, 
see  pp.  305-311  in  the  August  number.) 

SECOND 

Eric  G.  Shalkhauser  of  Peoria,  Illinois,     jvl r. 

Shalkhauser  wins  the  150-3000-meter  Grebe  Tuned 
Radio-Frequency  Amplifier.  His  clear  and  com- 
plete article  on  a  portable  Grimes  "  Inverse  Duplex" 
loop  receiver  is  full  of  practical  help  for  the  experi- 
menter. His  aggregate  mileage  of  48,745  is  excellent 
for  loop  reception. 

THIRD 

Miss — get  that! — Miss  Abbye  M.  White,  Baer 
Avenue,  Hanover,  Pennsylvania.  The  originality 
of  her  home-made  set  and  the  excellent  description, 
photos,  and  diagrams  which  she  submitted  were 
unanimously  awarded  the  Third  Prize — three  vac- 
uum tubes  (choice  of  UV-201's,  UV-199's,  WD-11's 
or  WD-12's),  although  her  total  mileage — 60,595  on 
an  outdoor  antenna  (96  stations  more  than  1 50  miles 
away  of  which  18  were  more  than  1,000  miles) — was 
considerably  below  the  records  of  several  others 
whose  contributions  did  not  fulfil  the  other  require- 
ments so  well. 

FOURTH 

Harry  Blumenfeld,    of  Cleveland,  Ohio.  The 

winner  of  this  prize,  the  Timmons  Loud  Speaking 
Unit,  did  all  his  DX  work  with  an  Armstrong  three- 
circuit  regenerative  set. 

Now  we'll  let  the  winners  tell  their  own 
stories,  and  we  hope  that  each  of  you  will  find 
something  of  particular  interest  and  definite 
suggestion  which  you  can  use  in  your  own 
radio  work. 


In  Tune  with  the  Infinite 


The  Description  of  a  Practical,  Portable,  "Inverse  Duplex"  Receiver, 
with  Some  Interesting  Remarks  About  its  Construction  and  Behavior 

By  ERIC  G.  SHALKHAUSER 

(SECOND  PRIZE) 

Articles  describing  the  theory,  construction,  and  operation  of  the  Grimes  "  Inverse  Duplex"  circuit  have 
appeared  in  the  April,  July,  and  August  issues  of  Radio  Broadcast.  What  Mr.  Shalkhauser  does  in  this 
article  is  to  show  how  he  has  developed  the  Grimes  circuit  in  a  four-tube  loop  outfit  that  is  portable,  depend- 
able, and  rugged.  Anyone  who  has  expeiimented  with  the  "Inverse  Duplex"  or  who  has  had  experience 
in  building  his  own  radio-frequency  outfits,  should  be  able  to  construct  a  set  similar  to  Mr.  Shalkhauser's 
from  the  circuit  diagram  and  the  several  clear  photographs  published  with  this  article.  We  should  like  to 
hear  from  those  of  our  readers  who  undertake  to  develop  outfits  of  this  kind. — The  Editor. 


T 


HE  receiver  shown  in  the  photo- 
graphs as  assembled  in  permanent 
form,  has  gone  through  many  stages 
of  experimental  work  before  the  very 
best  results  were  obtained.  A  four- 
tube  set  was  finally  chosen  in  preference  to  a 
two-  or  three-tube  set,  primarily  because  the 
small  percentage  of  energy  that  a  loop  antenna 
will  pick  up  in  comparison  with  an  out-door 
type  necessitates  much  more  amplification  to 
assure  satisfactory  results  at  all  times.  The 
average  listener  does  not  realize  what  obstacles 
the  radio  man  has  to  overcome  and  cannot 
understand  why  so  many  sets  operate  spas- 
modically. With  this  loop  receiver  it  has  been 
comparatively  simple  to  tune  in  the  West  Coast 


201 -A 


THE  RUGGED  CARRYING  CASE 
Everything  is  inside:  4-tube  Inverse  Duplex,  loop,  all 
batteries  and  phones.    Unlike  many  so-called  portable 
sets,  this  one  is  precisely  what  the  name  implies 


7-TURN  LOOP 
2  FT.  SQUARE 

400-0HM 


THREE  RADIO  AND  THREE  AUDIO  STAGES 
With  a  tube  detactor,  they  make  up  Mr.  Shalkhauser's  4-tube  circuit  which  he  operates  from  a  two-foot  loop 


4i8 


Radio  Broadcast 


THE   RECEIVER  CAN   BE  LIFTED  RIGHT  OUT 

Mr.  Shalkhauser  showing  how 
easy  it  is  to  get  at  the  "works" 


stations  most  any  evening  of  the  week,  from 
Peoria,  111.    The  distance  is  about  2,000  miles. 

The  receiver  was  constructed  with  the  idea 
that  it  must  be: 

1  Easily  portable  (of  the  one-man  type). 

2  Simple  yet  efficient  in  tuning. 

3  Rugged  but  sensitive. 

•  The  receiver  was  assembled  in  January  of 
this  year.  Four  months  of  experimenting  with 
radio  apparatus  found  on  the  market  to-day, 
resulted  in  the  combination  of  parts  shown  in 
the  photographs.  All  makes  and  types  of 
radio-  and  audio-frequency  transformers  avail- 
able were  given  a  trial.  The  various  makes 
of  tubes  showed  a  great  deal  of  difference  when 
combined  with  these  transformers. 

The  hook-up  as  at  present  used  in  the  set  is 
the  Grimes  "Inverse  Duplex,"  a  modification 
of  the  French  Latour  circuit  used  during  the 
war.    Using  the  regular  Latour  circuit  good 


results  can  be  expected  if  the  tubes  in  the 
second  and  third  stages  of  amplification  are  not 
overloaded.  This,  however,  is  difficult  to  avoid 
with  the  ordinary  vacuum  tube,  and  the 
modification  according  to  Grimes  proves  a 
decided  advantage. 

Many  types  of  loops  were  tried  with  varying 
results.  The  size  finally  decided  upon  was  a 
loop  two  feet  square  wound  with  seven  turns 
of  large-size  lamp-cord  wire  f-inch  spacing  is 
used  between  the  centres  of  adjacent  turns. 
Connection  is  made  with  the  receiving  set 
through  a  plug  and  jack  arrangement,  making 
it  possible  to  swing  the  loop  in  any  direction 
desired.  Good  contact  is  assured  at  the  same 
time.  Not  only  is  it  possible  to  select  stations 
lying  in  the  same  plane  with  the  loop,  but 
directional  effects  are  experienced  depending  on 
which  end  of  the  loop  is  connected  to  the  grid 
of  the  first  amplifier  tube.  The  grid  end  point- 
ing to  the  station  desired  gives  stronger  signals 
than  when  the  loop  is  rotated  through  180 
degrees.  WBAD  at  Minneapolis  lies  in  the 
same  plane  with  Atlanta,  Georgia  and  Peoria, 
Illinois.  Yet  by  swinging  the  loop  through 
180  degrees,  when  both  stations  were  sending 
on  identically  the  same  wavelength  at  the  same 
hour,  either  one  could  be  received  in  preference 
to  the  other.  This  property  of  the  loop  is  not 
generally  known. 

With  the  potentiometer  in  series  as  shown 
in  the  diagram,  selectivity  is  greatly  increased. 
Stations  sending  close  by  have  a  tendency  to 
paralyze  the  set.  Putting  resistance  into  the 
circuit  will  prevent  this  as  the  energy  effecting 
the  first  amplifier  tube  is  decreased. 

The  loop  itself  folds  up  in  compact  form  and 
is  carried  in  the  cabinet. 

Experiments  were  carried  on  with  the  UV-200 
the  UV-20i,the  UV-201-A,  the  French  amplifier, 
theold  Moorhead,andthe  UV-199.  Inconnect- 
ion  with  these  tubes  the  various  types  of  radio 
and  audio-frequency  transformers  were  tried. 
Since  the  apparatus  used  in  the  duplex  circuit 
has  fixed  values  almost  throughout,  it  was 
necessary  to  choose  such  combinations  as  would 
give  proper  balancing  of  radio  and  audio 
currents.  The  UV-200,  UV-201  and  UV-201-A 
tubes  have  given  the  best  all-around  results. 
This  can  be  explained  by  the  fact  that  they 
have  been  on  the  market  longer  than  the  others, 
are  manufactured  under  standard  and  well 
established  principles  and  were  used  in  the 
design  of  the  transformers  to  meet  their 
particular  characteristics.    The  WD-i  1  and 


In  Tune  with  the  Infinite 


419 


UV-199  tubes  will  need  specially  designed 
transformers  for  best  operation. 

Acme  radio  transformers  R-2,  R-3  and  R-4 
were  used  for  the  first,  second  and  third  radio- 
frequency  stages,  respectively,  and  gave  by  far 
the  best  results.  The  Atwater-Kent  audio 
transformers  served  best  in  the  audio-frequency 
circuits.  For  the  first  and  second  stages  the 
10-1  ratios  were  used,  for  the  third  the  5-1 
ratio.  No  by-pass  condensers  were  necessary 
across  the  secondary  of  the  audio  transformers, 
the  distributed  capacity  being  amply  large  to 
allow  the  radio-frequency  currents  to  pass. 

Critical  adjustments  for  the  amplifier  tubes 
are  not  essential,  although  it  has  been  found 
desirable  to  place  separate  rheostats  in  each 
filament  circuit.  The  detector  tube  has  a 
vernier  control  for  best  results.  For  long 
distance  reception  the  vernier  adjustment  is 
particularly  useful. 

Following  is  the  list  of  parts  used: 


3  UV-201  or  UV-201-A  tubes   $19.50 

1  UV-200  tube   5.00 

3  Cutler-Hammer  rheostats   3.00 

1  Cutler-Hammer  rheostat,  vernier  .     .     .     .  1  . 50 

1  Kellogg  .001  mfd.  vernier  condenser    .     .     .  8.75 

2  Atwater-Kent  10-1  ratio  audio  transformers  .  10.00 
1  Atwater-Kent  5-1  ratio  audio  transformer     .  4.00 

3  Acme  radio  transformers,  R-2,  R-3,  R-4  .  15.00 

3  Micadon  .001  fixed  condensers   1.20 

1  Micadon  .0025  fixed  condenser   .40 

1  Grid  leak  and  condenser  .0005   .50 

2  Single-circuit  jacks                                 .     .  1.40 

1  Acme  potentiometer   1 .  50 

2  Round  plugs   3.00 

1  Dictograph  headset   8.00 

4  Dry  cells   1 .80 

2  225-volt  Burgess  B  batteries   4.  50 

1  Panel   2.40 

4  Sockets    3 . 00 

4  Binding  posts   .20 

75  feet  single  lamp  cord   .75 


$95 .40 

The  most  remarkable  advantage  of  this 
receiver  over  all  others  lies  in  its  simple  yet 
very  efficient  tuning  properties.  After  proper 
adjustment  of  the  rheostats  the  condenser  is  the 
only  tuning  device  used.  Absolutely  none  of 
the  characteristic  whistling  noises  can  be 
heard.  The  station  tuned  to  merely  swings  in 
and  out  again  as  the  wave  is  passed.  Very 
little  static  interference  is  in  evidence.  It  is  a 
pleasure  to  work  with  this  circuit  after  having 
been  accustomed  to  one  which  is  more  noisy 
and  in  which  every  beat  note  can  be  heard 
through  the  head-phones.  Using  an  .001  mfd. 
vernier  condenser,  the  longer  range  of  wave- 
lengths used  since  May  15th  can  be  tuned  in 
properly.    The  entire  set,  including  dry  cells, 


UNPACKING  THE  LOOP 

A  place  is  provided  for  it  at  the 
back  of  the  horizontal  tuning  panel 

weighs  less  than  the  ordinary  80-ampere-hour 
storage  battery.  It  is  ideal  for  camping  trips 
and  automobile  use. 

Hints  for  proper  construction  and  operation: 

1.  Above  all,  avoid  the  ordinary  kind  of  flux  when 
soldering  connections.  Use  pure  rosin  and  good 
solder.  This  set  functioned  about  15  per  cent, 
of  normal  the  first  time  it  was  assembled  after 
experimenting.  Acid  had  gotten  into  several  of 
the  parts,  particularly  the  by-pass  condensers 
and  jacks,  and  ruined  them  for  further  use.  All 
connections  must  be  soldered  well  unless  good 
contact  can  be  made  through  jacks  or  binding 
posts. 

2.  Use  large  size  wire.    There  is  a  world  of  difference 
-  between  No.  18  bell  wire  and  No.  14  copper 

wire  in  connecting  up  the  parts.  Avoid  as  much 
as  possible  running  wires  parallel.  If  it  is  done, 
keep  them  at  least  one-half  to  one  inch  apart. 

3.  Set  all  radio- and  audio-frequency  transformers  so 


420 


Radio  Broadcast 


THE  LOOP  IS  QUICKLY  SET  UP 

The  fact  that  with  a  set  of  this  type  you  have  no  antenna- 
wire  to  stretch  from  tree  to  tree,  or  ground  connection  to 
make,  is  an  additional  argument  for  using  the  loop  on  a 
portable  set 

that  they  stand  at  right  angles  to  each  other  and 
at  least  four  inches  apart.  Shielding  is  desirable 
but  not  essential. 

4.  Follow  the  circuit  diagram  when  assembling  the 
parts.  I  have  assembled  this  set  dozens  of  times 
and  have  never  experienced  any  trouble  in  getting 
at  least  a  few  stations  at  the  first  trial  made. 

5.  Not  all  tubes  function  alike.  The  mere  changing 
about  of  two  amplifier  tubes  will  often  make  a 
decided  change  in  the  signal  strength. 

6.  The  UV-201-A  amplifier  is  used  when  operating 
with  dry  cells  on  the  filaments.  Special  binding 
posts  are  provided  for  storage  battery  operation 
with  the  UV-201  amplifiers. 

7.  If  the  set  is  functioning  properly  a  decided  click 
can  be  heard  in  the  head-phones  when  the  grid 
connection  to  the  first  amplifier  tube  is  touched 
with  the  moistened  finger.    The  tubes  must  of 


course  be  turned  on.  This  is  also  true  when  the 
grid  of  the  detector  tube  is  touched. 

The  following  is  a  list  of  stations1  heard  dur- 
ing the  months  of  February,  March,  April  and 
part  of  May,  1923,  on  the  four-tube  portable 
loop  receiver,  all  stations  having  been  received 
with  such  signal  strength  that  little  doubt 
remains  about  mistakes  having  been  made: 


KHJ,  KWH,  KYJ 

KUO 

WBZ 

WGI 

KNJ 

PWX 

KDYS 

WO  A I 

WDAE 


Los  Angeles  '.955 

San  Francisco  2,015 

Springfield,  Mass.  '.045 

Medford  Hillside,  Mass.  1,040 

Roswell,  N.  M.  1,190 

Havana  1,500 

Great  Falls,  Mont.  1,420 

San  Antonio,  Tex.  1,160 

Tampa,  Fla.  1,160 


'Editor's  Note:  As  there  is  not  space  to  print  Mr. 
Shalkhauser's  complete  list,  only  the  stations  over  1,000 
miles  from  Peoria,  111.  are  given  here. 


THE  OUTFIT  READY  FOR  USE 
The  hinged  front  side  of  the  cabinet  might  well 
be  provided  with  a  support  and  used  as  a  desk 


Hearing  North  America 

An  ingenious  arrangement  of  apparatus  permitting  any  one  of  five  circuits  to  be  used 
By  MISS  ABBYE  M.  WHITE 
(THIRD  PRIZE) 


RATHER  fearfully  I  venture  into 
your  contest,  for  I  do  not  know  if 
we  of  the  fair  sex  are  allowed  in  or 
not.  Rut  your  rules  say  nothing 
against  it — so  here  I  am. 
The  set  1  am  going  to  describe  is  not  so 
unusual  except  that  I  have  at  instant  command 
any  one  of  five  different  circuits — all  efficient — 
and  each  having  a  different  purpose.  My  set 
is  entirely  homemade — and  I  had  great  fun  in 
constructing  it. 

When  I  first  made  my  set  I  used  the  Rein- 
artz  circuit  alone — and  then,  finding  in  it  some 
shortcomings,  I  modified  it  to  use  a  double- 
circuit  which  is  far  more  selective  although 
slightly  more  difficult  to  adjust.  The  original 
cabinet  was  made  to  accommodate  a  panel 
8"x  10",  being  5"  in  depth.  I  thus  had  a  very 
compact  receiver.  Upon  modifying  it  I  did 
not  change  the  cabinet  but  simply  added 
additional  binding  posts  on  the  rear — and  used 
three  spider-web  coils  and  one  extra  condenser 
for  my  other  hook-ups. 

Before  going  into  the  actual  construction  of 
the  set  I  wish  to  say  some- 
thing of  the  circuits  used. 
The  Reinartz  as  we  all  know 
is  fairly  selective  as  long  as 
there  is  no  local  interfer- 
ence. It  is  particularly 
efficient  on  amateur  waves 
— and  amateur  stations  from 
every  district  have  been 
copied  by  its  use.  The  cir- 
cuit I  used  has  a  wavelength 
range  that  goes  up  beyond 
six  hundred  meters,  for 
many  ships  in  the  Atlantic 
have  also  been  copied.  The 
reason  for  my  looking  for 
another  circuit  is  that  sta- 
tion 3ACY  is  located  about 
three  blocks  away  and  he  is 
"pounding  brass"  with  a 
|-KW  spark  all  day  long — 
hence  I  needed  something 
more  selective.  The  spider- 


web  coils  appealed  to  me  because  they  were 
easily  constructed  and  offered  a  tuning  ele- 
ment which  had  very  little  distributed  capac- 
ity and  the  resistance  could  be  much  reduced 
and  hence  the  tuning  made  very  sharp.  So 
I  made  three  of  these  coils  and  mounted 
them.  1  tried  two  different  circuits — one  the 
ordinary  two-circuit  tuner  employing  tickler 
feed-back,  and  the  second  a  modification  of 
the  efficient  Weagant  circuit.  The  latter  is 
my  favorite,  but  offers  one  objection  in  that 
the  impedance  of  the  phones  enters  into  the 
tuning  and  an  additional  pair  of  phones  cannot 
be  added  or  an  amplifier  hooked  in  without 
retuning.  The  optional  circuit  shown  by 
dotted  lines  in  Fig.  1  overcomes  this  objection 
in  that  any  number  of  phones  can  be  connected 
or  taken  out  without  detuning. 

Thus  far  I  have  described  only  three  circuits, 
and  you  may  wonder  where  the  other  two  come 
in.  They  are  formed  by  simply  disconnecting 
the  primary  spider-web  coil  P  and  hooking  the 
aerial  lead  to  the  switch  lever  on  coil  S  and 
the  ground  lead  to  the  opposite  side  of  the  same 


MISS  ABBYE  M.  WHITE 


422 


Radio  Broadcast 


FIG.  I 

In  this  optional  circuit,  an  extra  pair  of  phones 
can  be  hooked  in  without  detuning  the  set 


coil.  Thus  1  now  have  a  single  circuit  tuner— 
which  can  be  connected  in  either  of  the  two 
methods  described  before.  I  employ  the  tuner 
in  this  manner  late  at  night  or  when  little 
interference  is  experienced,  to  do  DX  work — 
for  I  have  found  nothing  as  efficient  as  the 
single-circuit  tuner  for  distant  work.  Of 
course,  during  the  evening  (or  when  3ACY  is 
working)  1  do  not  employ  the  single-circuit  but 
use  the  two-circuit,  since  it  is  more  selective. 

Now  as  to  the  materials  needed  for  the  con- 
struction of  the  set. 

1    formica  panel  8"  x  10" 
i    tube  socket 

1  UV  -200  or  any  other  good  detector  tube 
24  binding  posts 

2  porcelain  knobs 
6  switch  levers 

1    box  brass-headed  upholstering  tacks 

1    pair  phones 

1    6-volt  A  battery 

(unless  dry  cell  tubes  are  used) 
1    B  battery 

1  vernier  rheostat 

2  23-plate  variable  condensers 
1    1 3-plate  variable  condenser 

1    pair  hinges 

Odd  pieces  of  cardboard,  wood,  screws,  tinfoil,  etc. 

The  approximate  cost  of  the  above,  including 
an  80-ampere-hour  A  battery  is  about  thirty- 
five  dollars. 

First  1  will  take  up  the  construction  of  the 
original  Reinartz  unit.  As  said,  the  panel 
was  8"  x  10".  The  photographs  will  give  quite 
an  effective  view  of  the  manner  in  which  the 
various  units  are  mounted.  Although  many 
magazine  articles  give  descriptions  of  this 


circuit  and  show  a  coil 
mounted  to  one  side  of  the 
condensers  or  the  condensers 
mounted  close  together,  1 
contend  that  the  arrange- 
ment I  have  adopted  is  best 
for  selective  tuning  and  to 
eliminate  body  capacity.  1 
arrived  at  this  conclusion 
after  much  experimental 
work  and  feel  justified  in 
what  1  say.  In  the  mount- 
ing shown  I  have  my  vari- 
able condensers  well  spaced 
— and  not  too  close  to  the 
spider-web  coil.  As  you  will 
note  from  the  picture  of  the 
rear  view  of  the  cabinet, 
(page  424)  the  coil  stands 
upright  and  close  to  the 
panel — this  arrangement 
also  adds  to  selective  and  sharp  tuning  by 
eliminating  long  leads  to  switch  points.  When 
I  made  my  original  set  1  made  the  switch 
levers  out  of  sheet  brass  —  the  knobs  were 
turned  from  walnut  and  the  shaft  made 
brass.    The  contacts  or  switch  points 


01    1  6 


were  of  brass  tacks — which  are  cheap  and  al- 
most as  effective  as  the  regular  article.  I  will 
not  give  any  definite  dimensions  of  the  panel 
layout,  for  it  is  best  to  lay  it  out  in  accordance 
with  the  sizes  of  the  condensers  used,  make  of 
rheostat,  switch  lever  lengths,  etc.,  but  the 
general  plan  shown  in  the  photo  should  be 
followed  for  best  results.  The  binding  posts 
originally  used  were  the  five  lower  ones  shown 
in  the  photo  mounted  on  a  strip  of  formica. 

Now  as  to  a  few  specific  instructions  about 
the  component  parts.  The  spider-web  coil 
was  made  on  a  wood  form — inside  diameter 
2\"  and  outside  diameter  6|"  and  had  seven 
spokes.  The  material  was  what  is  known  as 
five-ply  veneer  wood.  The  slots  were  cut  with 
a  hack  saw  and  edges  smoothed  with  a  file  to 
allow  easy  winding.  Photo-mounting  card- 
board could  have  been  used  for  the  form.  The 
wire  used  was  number  23  D.C.C.  and  as  Fig.  2 
will  show,  the  inside  section  of  winding — the 
"feed-back"  coil — consists  of  45  turns,  tapped 
at  o,  15,  30,  and  45.  Then  the  wire  was  cut 
and  the  antenna  and  grid  winding  put  on. 
Taps  were  taken  out  at  the  following  points, 
of  this  second  winding:  on  o,  1,  2,  3,  4,  5,  6,  7, 
8,  9,  10,  26,  33,  and  40.  The  first  four  taps 
from  the  feed-back  coil  were  attached  to  the 


Hearing  North  America 


four  switch  points  on  the  right  side  of  the  panel 
looking  at  it  from  the  front — above  and  to  the 
right  was  mounted  the  23-plate  feed-back  con- 
denser C3.  Then  the  taps  for  the  antenna 
tuning  were  attached  to  the  central  switch 
points.  The  10th  tap  is  connected  as  shown  in 
Fig.  2.  The  last  three  taps — at  26,  33,  and 
40 — were  attached  to  three  of  the  points  on  the 
left  switch  which  is  the  grid  tuning  switch  (a 
forth  point  was  added  to  make  the  panel 
symmetrical).  The  condenser  in  the  left  upper 
corner  is  the  13-plate  one  which  serves  to  tune 
the  receiver  to  the  desired  wavelength.  The 
coil  in  mounting  was  not  supported  by  any 
means  other  than  the  leads  to  the  switch  points 
themselves,  this  being  sufficient. 

As  will  be  noticed  the  grid  condenser  is 
mounted  on  a  short  piece  of  formica  fastened  on 
porcelain  knobs  seen  along  the  right  side  in  the 
photograph  of  the  rear  of  the  cabinet.  This 
grid  condenser  was  one  of  a  series  made  and  so 
arranged  that  they  were  easy  to  change.  Two 
brass  machine  screws  were  mounted  on  the 
formica  strip  and  the  condensers  were  made  by 
wrapping  tin  foil  with  a  paper  dielectric  on  a 
cardboard  form,  one  sheet  of  tinfoil  extending 
beyond  the  paper  dielectric  at  one  end  of  the 
form  and  the  other  sheet  of  foil  extending  from 
the  other  end.  Thus  the  connections  for  the 
condenser  were  made  at  each  end  by  soldering 
to  the  tinfoil  brass  washers  so  spaced  that  the 
holes  would  be  the  same  distance  apart  as  were 
the  two  brass  machine  screws  mounted  on  the 
formica.  In  this  manner 
the  condenser  could  be 
slipped  over  the  screws  and 
locked  into  place  with  a 
knurled  nut.  1  found  that 
a  condenser  which  had  about 
two  square  inches  of  effec- 
tive area  on  each  sheet  of 
foil  worked  best.  An  ordi- 
nary grid  condenser  could 
be  used  here.  The  leak, 
when  used,  consisted  of  a 
strip  of  paper  placed  on  the 
same  bolts  before  tightening 
the  nuts.  Pencil  lines  were 
then  drawn  until  the  correct 
resistance  was  obtained. 
The  two  binding  posts  on 
the  front  of  the  panel  are  for 
connecting  the  phones.  In 
making  connections  avoid 
running  leads  parallel — and 


keep  them  separated  as  far  as  possible.  Fig.  3 
gives  a  view  of  the  binding  posts  and  the  accom- 
panying table  on  page  424  will  show  what  leads 
are  connected  to  the  various  posts.  The  view  of 
the  posts  is  shown  as  looking  on  them  from  the 
rear  of  the  cabinet.  The  table  also  tells  which 
posts  to  connect  together  to  use  the  various 
circuits.  The  1 3-plate  condenser  is  always 
connected  across  from  the  side  of  the  grid 
condenser,  away  from  the  grid  to  the  positive 
of  the  filament  and  in  each  of  the  circuits  serves 
as  a  tuning  condenser.  To  eliminate  to  a  large 
extent  the  effect  of  body  capacity  in  tuning, 
condensers  should  be  connected  so  that  the 
movable  plates  are  connected  to  the  filament. 
Then,  too,  1  use,  instead  of  the  dials  for  tuning, 
a  rod  with  an  insulated  handle  attached  to  the 
knob  of  the  condenser — the  length  serving  in  a 
manner  like  a  vernier — in  that  it  moves  over  a 
considerable  distance  before  the  condenser 
plates  rotate  much,  thus  making  tuning  easy. 

The  cabinet  was  made  of  odd  pieces  of  wood 
picked  up  and  finished  with  walnut  stain, 
shellac,  and  wax. 

Now  as  to  the  three  spider-web  coils.  The 
mounting  is  almost  self  explanatory  from  the 
photo — the  wood  used  was  odd  bits  picked  up 
and  cut  to  shape.  The  only  thing  different 
in  the  spider-web  coils  I  used  is  that  they 
are  tapped — thus  permitting  sharper  tuning 
and  a  broader  range.  The  outside  diameter 
of  the  forms  is  6  inches,  inside  diameter  of  the 
primary  is  2  inches,  of  secondary  if  inches,  of 


FIG. 


The  wiring  diagram  used  by  Miss  While.  Various  circuit 
arrangements  are  produced  from  this  by  changing  connec- 
tions at  binding  posts  mounted  at  the  back  of  the  cabinet 


424 


Radio  Broadcast 


opposit 


tickler  2J  inches.  All  wire  used  in  winding 
the  coils  is  23  D.C.C.  and  the  number  of 
spokes  is  15.  The  forms  were  made  of  photo- 
mount  cardboard,  each  having  been  given 
several  coats  of  shellac  to  add  stiffness  and  to 
insulate.  The  primary  winding  consisted  of 
50  turns — taps  taken  out  at  the  35th,  40th, 
45th,  and  50th  turns.  The  secondary  con- 
sisted of  60  turns — taps  at  45,  50,  55,  and  60. 
The  tickler  coil  had  40  turns — taps  at  25,  30, 
35,  and  40. 

As  will  be  noted,  the  switch  levers  and 
points  on  the  two  outside  coils,  which  are  the 
primary  and  tickler,  were  mounted  directly 
on  the  wooden  hinged  arm,  and  the  switch 
points  for  the  central  coil  were  mounted  on 
the  support  on  which  the  hinges  for  the  other 
two  coils  are  fastened.  The  central  coil  was 
fastened  by  wire  supports  one  on  each  side  of 
the  coil — the  lower  extremities  of  these  sup- 
ports being  fastened  to  the  base  of  the  instru- 
ment. A  word  of  warning  in  making  any  kind 
of  coils :  never  use  shellac  on  the  windings  unless 
absolutely  necessary — for  it  adds  largely  to  the 
distributed  capacity  and  thus  "broadens"  the 
tuning. 

You  will  note  that,  when  the  set  was  modi- 
fied, the  additional  binding  posts  were  mounted 
directly  on  the  wood,  which  is  satisfactory  if 
the  wood  is  entirely  dry;  and  it  is  a  good  plan 
to  place  the  whole  set  and  spider-web  coils 
after  mounting,  near  the  stove  or  some  other 
warm  place,  so  as  to  dry  the  wood  and  the 
alcohol  out  of  the  shellac  used  to  cover  the 
woodwork. 

My  antenna  consists  of  two  wires  about 
90  feet  long  at  a  height  of  about  35  feet.  The 


earth  is  used  as  a  ground 

but   excellent    results  are 

also  obtained  by  using  the 

ungrounded  side  of  the 

house  lighting  circuit  as  a 

counterpoise. 

Connections  made  to  posts 
shown  in  Figs.  3  and  4. 

No.    1  to  one  phone  post  on  front 
of  cabinet 

2  to  No.  4 

3  to  rheostat — other  side  of 
rheostat  tc  one  side  of  fila- 
ment 

4  to  other  side  of  filament 

5  to  antenna  switch  in  Run- 
artz  circuit 

6  to  fixed  plates  of  13-plate 
condenser  and  to  one  side 
of  grid  condenser  —  other 
side  of  grid  condenser  goes 
to  grid 

7  to  grid  switch  in  Reinartz  circuit 

8  to  plate  of  vacuum  tube 

9  to  10th  turn  tap  in  Reinartz  circuit 

10  to  plate  switch  in  Reinartz  circuit 

1 1  to  other  phone  post  on  front  of  cabinet 

12  to  45th  turn  tap  on  feed-back  winding  of  Reinartz 
circuit 

13  to  fixed  plates  in  23-plate  condenser 

14  to  movable  plates  of  23-plate  condenser 

To  connect  Reinartz  circuit: 

Connect  post   7  to  post  6 

4  to  9  and  to  plus  A  and  ground 
8  to  10  and  to  1  1 

2  to  minus  of  B  battery 
1  to  plus  of  B  battery 

12  to  13 

14  to  5  and  to  aerial 

3  to  minus  of  A  battery 

To  connect  Weagant  circuit: 

Connect   8  to  1 1  and  to  one  side  of  tickler  coil 

1  to  plus  of  B  battery 

2  to  minus  of  B  battery 
4  to  plus  of  A  battery 

3  to  minus  of  A  battery 

4  to  14  and  to  one  side  of  secondary 
6  to  other  side  of  secondary 

13  to  other  side  of  tickler 
Primary  as  shown  in  diagram,  Fig.  1. 

To  connect  to  optional  circuit  shown  in  Fig.  1,  hav- 
ing made  the  above  connections: 

Change  11  from  8  to  13. 

A  little  should  be  said  about  the  tuning  of 
the  receiver.  In  the  Reinartz  circuit,  the 
feed-back  condenser  is  set  so  that  it  is  about 
half  its  maximum  capacity  in  the  circuit — and 
the  feed-back  switch  placed  on  the  point  to 
which  the  15th  tapis  connected.  Now,  then, 
the  grid  switch  is  placed  on  the  40th  tap  and 
the  antenna  switch  tried  on  various  points, 
while  the  circuit  is  tuned  with  the  tuning  con- 
denser— the  13-plate  one — final  tuning  being 
done  with  the  feed-back  condenser.    If  signals 


Hearing  North  America 


do  not  come  through,  another  antenna  tap  is 
tried  and  the  same  procedure  followed.  For 
amateur  waves,  the  33-turn  grid  tap  is  used. 
It  may  be  found  that  a  different  tap  on  the 
feed-back  coil  will  work  better.  After  a  little 
experimenting  tuning  will  be  easy. 

With  the  spider-web  coils  it  may  be  found 
that  on  first  connecting  them,  the  set  may  not 
regenerate.  If  this  is  the  case,  change  the  leads 
to  the  tickler  or  feed-back  coil  and  the  set 
should  work  properly.  For  general  work,  a 
rather  loose  coupling  on  the  coils  is  desirable, 
thus  giving  less  interference — with  but  little 
decrease  in  signal  strength.  The  circuit  can  be 
tuned  by  moving  the  coils  closer  or  farther 
apart,  although  it  is  easier  and  better  to  use 
the  condensers  as  the  tuning  elements.  The 
spider-web  coils  cover  a  wave  range  consider- 
ably above  700  meters,  for  NAA  comes  pound- 
ing through  on  712. 

1  have  on  various  trials  been  able  to  receive 
phone  from  as  far  as  Chicago,  Atlanta,  and 
other  places  with  only  a  piece  of  wire  strung 


fig.  5 

Miss  White's  complete  receiver,  showing  home-made  spider-webs  and  mounting. 
Note  also  the  tuning  rods  attached  to  the  two  condenser  knobs  on  the  panel 


In  Radio  Broadcast's  "Lab" 

While  trying  the  many  receivers  sent  us  by  various  manufacturers  and  while  experimenting  with  all 
sorts  of  trick  hook-ups,  we  find  out  some  interesting  things.  If  you  are  of  an  experimental  nature,  you  must 
find  similar  circumstances  in  your  own  radio  laboratory — whether  it  be  a  neat,  well-equipped  workshop,  or 
a  table  of  junk  in  one  corner  of  your  room. 

Each  month  we  are  going  to  describe  our  findings  in  a  new  department  which  we  expect  will  suggest 
to  you  many  interesting  lines  along  which  to  conduct  your  own  experiments,  as  well  as  to  give- definite  re- 
ports of  the  performance  of  all  manner  of  radio  apparatus. — The  Editor. 


©  ©  ©  ©  © 

©        ©         ©  © 
©  ©  ©    ©  © 

FIG.  4 

The  arrangement  of  binding  posts  referred  to  in 
the  table  of  connections  on  the  opposite  page 

around  on  the  floor  of  the  room  as  an  aerial, 
using  the  Weagant  circuit  connected  as  a  single 
circuit.  On  the  whole,  my  set  has  afforded  me 
much  pleasure  and  has  not  given  the  trouble 
that  sets  seem  to  give  most  people  in  the  radio 
game.  1  can  travel  over  the  United  States 
and  yet  remain  at  home.  Nightly  I  visit 
most  of  the  larger  cities  in  the  U.  S.  and 
get  much  interesting  entertainment  and  in- 
struction. 


The  World  at  Your  Finger  Tips 


After  All  is  Said  and  Done,  the  Receiver  for  the  Fellow  "Who  Wants  Real  Results 
for  a  Limited  Expenditure  is  the  Good  Old  Armstrong  Three-Circuit  Regenerator 

By  H.  BLUMENFELD 

(FOURTH  PRIZE) 


BOY!  Page  the  radio  bug  who  sits 
up  night  after  night  and  twirls  dials 
until  his  fingers  ache  and  his  wrist 
is  all  bent  out  of  shape,  yet  doesn't 
get  a  thing.  For  I 
have  something  to  tell  him. 

Do  you  want  a  real  DX 
receiver?  Then  spare  a  few 
moments  and  read  the  follow- 
ing: 

After  experimenting  for 
more  than  a  year  on  various 
types  of  hook-ups — single- 
circuit,  two-circuit,  three- 
circuit,  super-regenerative, 
Flewelling,  reflex,  Reinartz, 
and  various  types  of  radio- 
frequency  circuits,  1  have  at 
last  settled  down  on  the  sim- 
ple, but  ultra-efficient  three- 
circuit  regenerative  circuit. 

We  are  now  going  to  work 
by  the  process  of 
elimination.  You 
may  argue  that 
the  three-circuit 
set  is  pretty  com- 
plicated for  the 
amateur  to  oper- 
ate as  there  are 
too  many  con- 
trols. Of  course 
this  set  is  prac- 
tical, but  since 
May  15th,  1923, 
when  all  stations 
went  on  separate 
wavelengths,  all 
of  these  controls 
became  unneces- 
sary. 

So  why  not  be 
economical  and 
get  the  same,  if 
not  better  re- 


OUT  OF  THE  WAY,  YET  HANDY 


suits?  The  super-regenerative  and  the  Flew- 
elling sets  are  only  in  their  early  stages  of  de- 
velopment, and  seem  to  produce  results,  but 
they  are  not  very  stable  in  DX  work,  as  yet. 

The  reflex  set  is  another  set  that  is 
hard  to  build  (although  very  satis- 
factory if  built  properly.)  Therefore, 
for  the  novice  the  only  set  that  it  is 
advisable  to  stick  to  and  experiment 
with  is  one  employing  the  Armstrong 
single-  or  three-circuit  system  of  re- 
generation. 

The  single-circuit  set  is  not  very 
selective  for  DX  work,  therefore 
there  is  but  one  good  circuit  left, 
and  that  is  the  famous  Armstrong 
three-circuit  receiver. 

It  is  very  selective  and  brings  in 
nearly  all  the  important  broadcast- 
ing stations  you  can  think  of. 

The  advantages  of  this  circuit  are: 
(1)  Ease  in  tuning  in  distant  stations. 
  , ...  „ ..  (2)  Economical. 

(3)  Only  4  con- 
trols necessary. 
(Condenser, 
Coupler,  Vari- 
ometer, and 
Rheostat.) 

(4)  Not  com  pi  i- 
cated. 


But  there  is  a 
small  phrase  be- 
hind this  efficient 
set  that  makes 
it  work  wonder- 
fully well  on  lo- 
cal and  distant 
stations. 

It  is,  "Use 
the  right  parts 
in  their  right 
places." 

The  following 
are  the  complete 


The  World  at  Your  Finger  l  ips 


427 


MR.   BLUMENFELD  S  COMPLETE  RECEIVER 
It  is  a  three-circuit  regenerator  with  two  stages  of  audio  amplification 


parts  needed  to  build  this  set  which  is  equipped 
with  a  two-stage  amplifier  for  additional  vol- 
ume: 

PARTS  NEEDED  FOR  DETECTOR  AND  TUNER 
i  Coupler 

1  Variable  condenser 

i  Variometer 

1  Rheostat  (vernier  type) 

1  Socket 

1  Vacuum  tube 

8  Binding  posts 

1  Panel  (7  x  12  x  fa)  (Formica  or  Bakelite) 

1  Base  (6  x  12  x  fa)  (mahogany) 

1  Grid  leak  and  condenser  (.00025  Mfd.) 

1  Switch  arm 

8  Taps  and  2  stops 

1  Jack  (closed  circuit) 

PARTS  NEEDED  FOR  AMPLIFIER 

2  Audio-frequency  transformers 

2  Vacuum  tubes  (UV-20I-A  recommended) 
2  Rheostats 
2  Sockets 

2  Jacks  (one  double-circuit  and  one  open-circuit) 
1  Panel  (7  x  12  x  fa) 
1  A  battery  switch 
5  Binding  Posts 

ACCESSORIES 

25  Ft.  tinned  copper  wire 
1  Doz.  flat  head  wood  screws  (brass) 
1  Storage  B  battery  of  68  volts,  or  3  22^-volt  dry  B 
batteries 

1  80-  to  120-ampere-hour  storage  A  battery  (6  volts) 

or  dry  cells  if  dry-cell  tubes  are  used 
1  Pair  of  phones  and  horn 
5  Clips  for  A  and  B  batteries 

OPTIONAL 

1  Book  case  as  shown  in  photograph 
1  Dozen  small  flexible  cords  for  connecting  set  to  back 
of  cabinet. 

In  the  detector  circuit  I  have  found  a  vario- 
meter in  the  grid  circuit  unnecessary. 

The  panel  is  a  very  important  factor  in  your 
set.    Bakelite  is  handsome  and  glossy  and 


will  last  for  years.  Keep  in  mind  that  every 
radio  bug  takes  a  great  pride  in  the  looks  of 
his  set. 

Bear  in  mind,  if  you  buy  cheap  parts,  you 
will  get  cheap  results;  and  if  you  buy  high 
grade  parts,  you  will  get  results  accordingly. 
This  does  not  mean  that  you  must  buy  high 
priced  parts.  By  no  means.  But  buy  shrewdly 
and  carefully.    You  won't  be  sorry. 

The  condenser  is  one  of  the  most  essential 
parts  for  this  circuit  unless  a  variometer  is  used 
to  tune  the  secondary  circuit.  So,  when  you 
get  one,  get  a  good  one.  And  then  purchase 
a  vernier  of  the  button  type  which  has  a  little 
beveled  edge  (rubber)  which  meets  the  bevel 
side  of  the  dial. 

Any  good  variometer  may  be  used. 

So  much  for  the  detector.    The  amplifier: 

Most  any  transformer  can  amplify  of  course. 
Never  doubt  it.  But  many  of  them  will  cause 
howling,  hissing,  produce  distortion,  in  fact 
everything  but  real  music. 

So  a  good  transformer  is  very  essential  to  any 
set. 

Two  steps  of  amplification  are  required  on 
this  set,  which  will  work  a  loud-speaker  in 
excellent  shape. 

Make  all  connections  as  short  as  possible, 
and  solder  them  carefully.  Do  not  run  any 
wires  parallel  for  any  long  distance.  The  aerial 
should  be  a  single  wire  at  least  75  feet  long 
and  not  more  than  1 50  feet  long  and  about 
30  or  more  feet  high. 

On  a  cold,  clear  night  this  set  reaches  out 
its  long  hand  and  simply  grabs  the  distant 
stations. 

On  local  stations,  the  signals  should  roar  in 
with  terrific  volume.  In  three  months  I  have 
heard  196  stations  150  or  more  miles  from  my 
home  in  Cleveland.  My  total  mileage  is 
145, 179  miles. 


^28 


Radio  Broadcast 


THE  THREE-CIRCUIT  REGENERATIVE  CIRCUIT 

It  is  very  common  and  quite  old,  but  it  is  still  delivering  the  goods.  The  two  stages  of  audio  amplification 
make  possible  the  use  of  a  loud  speaker.  The  parts  include  A,  antenna;  C,  antenna  series  condenser  (.0005 
mfd);  P,  primary  of  variocoupler;  G,  ground;  S,  secondary  of  variocoupler;  C2,  secondary  tuning  condenser 
(.0005  mfd);  C,,  grid  condenser  and  leak;  d,  detector  tube;  R,  R,,  and  R.,,  rheostats;  Gj,  ground  from  nega- 
tive of  A  battery;  V,  plate  variometer;  C3,  telephone  condenser;  (.002  mfd);  J,  and  J„,  circuit-closing  jacks; 

J3,  open-circuit  jack 


The  enclosed  photos  speak  for  themselves. 
There  is  no  need  for  the  reader  to  have  a  panel 
layout.  Perhaps  the  layout  does  not  suit  him. 
But,  for  the  radio  bug  who  does  not  want  to 
take  the  time  to  lay  out  a  set,  the  photo  shows 
very  clearly  how  to  do  it,  as  well  as  how  to 
mount  the  set,  which  when  finished  will  look 
as  well,  especially  to  its  maker,  as  the  highest 
priced  set  on  the  market. 

In  the  B  battery  circuit  will  be  seen  a  .25- 
ampere  fuse.  This  is  used  because  the  A  and 
B  battery  wires  might  become  crossed  acci- 
dentally and  burn  out  the  tube.  This  is  very 
expensive  in  the  end  as  a  tube  costs  quite  a 
bit  of  money  nowadays.    So  with  this  method, 


the  fuse  will  burn  out  instead  of  the  tube  and 
the  former  is  much  the  less  expensive. 

A  variable  condenser  of  .005  mfd.  may  be 
put  across  the  secondary  of  the  variocoupler 
for  greater  selectivity,  although  this  is  not 
necessary. 

If  possible,  use  a  separate  ground  for  the 
negative  filament. 

This  set  when  finished  and  put  into  a  cabinet 
as  shown,  will  look  very  well. 

You  will  just  blush  with  pride  when  a  person 
looking  at  the  set  says,  "My,  what  a  beautiful 
set." 

And  not  only  that — but  it  works,  and  it 
works  well. 


In  the  Wake  of  the  Winners 

The  response  to  the  Receiving  Contest  was  not  limited  by  the  boundaries  of  the 
United  States.  Reports  from  Canada,  England,  Porto  Rico,  and  ships  at  sea  poured  into 
the  editorial  office.  Some  of  these  were  almost  undecipherable  scribbles  on  both  sides  of 
small  slips  of  paper;  others  were  neatly  typewritten  sheets  accompanied  by  excellent 
photos  and  full  of  material  that  is  bound  to  intrigue  the  interest  of  any  broadcast  fan. 
Next  month,  we  will  announce  the  Honorable  Mention  contestants,  and  will  print  as 
much  of  their  contributions  as  space  permits.  A  summary  of  the  contest  results, 
together  with  some  general  conclusions  about  broadcast  receiving,  will  also  appear. 
— The  Editor. 


Broadcasters  in  New  York,  Paris, 
and  Los  Angeles 


GENERAL  PERSHING  TALKS  TO  A  MILLION  A  SPANISH  POET  AT  A  FRENCH  STATION 
At  least  that  number,  it  is  estimated,  heard  M.  Carnido   is  shown  broadcast- 

his  recent  speech  given  at  WEAF  (New  York)  ing  some  of  his  own  poetry  through 

and  rebroadcasted  by  WCAP  (Washington,  the  Eiffel  Tower  station,   in  the 

D.  C.)  and  WMAF  (Dartmouth,  Mass.)  town  called  Paris 


THIS  SEXTETTE  FURNISHES  IRRESISTIBLE  DANCE  MUSIC  FOR  KHj's  AUDIENCES 
It  is  the  Filipino  String  Sextette  from  the  Bluebird  Cafeteria  in  Los  Angeles.    The  four  steps  of  banjo-frequency 
amplification,  violin  detector,  and  one  base  guitar  form  a  hook-up  that  is  exceedingly  popular  throughout  the  West 


What  You  Should  Know  About 

Condensers 

Molecules,  Elements,  Conductors,  and  Dielectrics.  The  Action  of 
Electrons  at  Condenser  Plates.   Capacity,  Inductance,  and  Resistance 

By  ALLEN  D.  CARDWELL 
PART  I 

If  receiving  set  owners  would  buy  their  variable  condensers  after  a  survey  of  the  mechanical  and 
electrical  characteristics  of  the  types  on  sale,  rather  than  from  a  comparison  merely  of  general  appearance, 
hearsay  and  price,  there  would  be  less  trouble  with  thousands  of  receiving  sets  and  less  apparatus  of  inferior 
quality  on  the  market.  Of  course,  to  the  uninitiated,  a  43-plate  condenser,  for  instance,  is  simply  one 
unit  in  a  collection  of  junk  that  he  has  to  buy  and  connect  up  before  he  can  hear  the  evening  programs. 
So  he  trots  down  to  the  store,  looks  at  his  list  and  buys,  among  other  things,  "1  variable  condenser  (43- 
plate)."  Now,  when  we  are  dealing  in  electrical  circuits  passing  inconceivably  weak  currents,  the  best  is 
none  too  good  in  a  condenser  to  be  used  in  these  circuits.  It  seems  to  us,  then,  that  a  familiarity  with 
good  and  bad  condenser  construction  is  worth  any  enthusiast's  while  to  obtain;  and  we  feel  sure  that 
any  one  who  reads  the  two  installments  of  this  article  by  Mr.  Cardwell,  will  find  the  knowledge  he  has 
gained  to  be  of  practical  dollar-and-cents  value  to  him. — The  Editor. 


R 


ECENT  research  into  the  nature  of 
electrical  phenomena  has  given  us 
substantial  ground  work  on  which 
to  rationalize  the  rather  complex 
theory  of  condensers  and  their  ef- 
fects.   We  no  longer  say  that  electricity  is  a 


"current"  and  do  not  have  to  avoid  specifying 
what  it  is.  To-day  we  understand  electricity 
to  be  a  characteristic  movement  of  electrons. 
We  can  explain  practically  all  radio  problems 
on  the  electron  theory,  and  it  is  hardly  possible 
to  understand  the  action  of  condensers  without 
some  general  idea  of  electron 
currents  and  their  charac- 
teristic effects. 


THE   CHEMICAL  BASIS  OF 
ELECTRICAL  ENERGY 


1  tO1 


NATURAL  CONDENSERS — STORM  CLOUDS 
The  lightning  discharge  illustrates  the  rupture  of  the  dielectric 


IE  first  approach 
toward  electron  study 
begins  with  chemistry.  If 
we  take  any  substance,  we 
can  break  it  down  into  cer- 
tain chemical  units  which 
are  called  molecules.  The 
molecule  is  the  smallest  unit 
of  the  material  which  will 
look,  taste,  smell,  or  react 
with  the  characteristic  ef- 
fects of  the  substance  as  a 
whole.  For  example,  pure 
water  always  looks  the 
same,  tastes  the  same,  and 
will  interact  in  the  same 
way  with  other  given  sub- 
stances. The  material  we 
call  water  is  a  liquid,  the 
smallest  unit  of  which  is 
the  molecule.    If  we  break 


What  You  Should  Know  About  Condensers 


43' 


FIG.  I 

Electron  orbits  about  an  atom 
\  theoretical  illustration  to 
visualize  the  general  idea.  The 
orbits  are  not  necessarily  in  the 
same  circumference,  nor  has  it 
been  proven  that  they  revolve, 
some  asserting  that  the  elec- 
trons have  a  reciprocating 
motion 


up  the  molecule  by  proper  chemical  agencies, 
we  can  further  reduce  its  component  units 
into  indivisible  particles  which  we  call  ele- 
ments. There  are  some  8o-odd  elements  that 
have  been  discovered  thus  far,  from  which  we 
build  up  the  entire  physical  universe — rocks, 
trees,  animal  life,  metals,  etc.  Some  of  the 
elements  are  found  in  nature  in  a  pure  state; 
for  example,  a  diamond  is  nearly  pure  carbon. 
Gold,  silver,  lead,  etc.,  are  'metallic'  elements 
often  found  isolated  or  uncombined  with  other 
elements.  The  elements  are  the  units  which 
give  us  by  characteristic  combinations,  mole- 
cules and  the  molecules  in  turn  give  us  the 
distinguishing  qualities  of  any  uniform  or 
homogeneous  substance  such  as  sugar,  water, 
air,  granite,  iron  ore,  etc.  (Homogeneous 
does  not  include  mixtures  such  as  plaster, 
sealing  wax,  glass,  etc.)  We  can  go  further, 
however,  and  break  up  the  molecules  into 
groups  of  atoms  and  these  in  turn  we  find  are 
composed  of  characteristic  combinations  of 
electrons.  The  number  of  electrons  in  a 
characteristic  group  determines  the  atom,  and 
the  groups  of  atoms  determine  the  molecule. 
All  electrons  are  identical  regardless  of  what 
molecule  or  element  they  may  be  a  part  of. 
The  only  distinguishing  characteristic  of  an 
electron  is  its  electrical  state,  it  may  either 
possess  an  electrical  charge  or  it  may  be  lacking 
in  electrical  energy.  The  average  number  of 
electrons  without  charges  are  counterbalanced 
by  a  like  number  with  charges  in  the  normal 
conductor  which  possesses  no  difference  of 
potential  between  any  given  points.  A  pre- 
ponderance of  charged  electrons  or  non-charged 
electrons  will  cause  a  difference  of  potential 
and  a  flow  of  electrical  energy.  Electrons 
which  are  similarly  charged  tend  to  repel  one 
another  so  that  in  a  conductor  which  possesses 
a  preponderance  of  charged  electrons  this 
phenomena  of  mutual  repulsion  causes  an 
equal  distribution  of  current-carrying  electrons, 
inasmuch  as  wherever  there  is  a  greater  gather- 
ing of  similarly  charged  electrons  there  is  also 
a  greater  tendency  to  disperse  them.    It  may 


seem  absurd  to  reduce  all  forms  of  matter  to 
one  common  base,  but  science  has  vindicated 
the  conception  of  the  atom  as  an  aggregation  of 
electrons  revolving  in  fixed  orbits  about  a 
neutral  centre. 

Electrons  have  these  peculiarities: 

1.  They  revolve  about  the  neutral  centre  of  the 

atom  in  fixed  orbits  (Fig.  i)  at  very  high 
velocities  (50  miles  a  second  approximately.) 

2.  They  are  affected  by  heat  and  their  speed  in- 

creases at  higher  temperatures. 

3.  Some  electrons  are  positive  and  some  are 

negative  in  their  electrical  charge. 

4.  The  weight  of  an  electron  has  been  calculated. 

Hence,  electrical  energy  has  weight! 

5.  The  tension  with  which  the  electrons  are  bound 

together  in  the  atom  combination  determines 
the  relative  "conductivity"  or  "insulation 
strength"  of  the  substance  formed  by  the 
electrons  of  the  atoms  in  the  molecules  of 
the  material. 

CONDUCTORS  AND  DIELECTRICS 

WE  FIND  that  substances  which  are 
classed  as  "  conductors  "  are  such  because 
some  electrons  in  the  atoms  composing  the  ma- 
terial can  be  dislodged.  That  is,  certain  groups 
of  electrons  in  each  atom  are  revolving  in  outer 
orbits  of  the  atoms  and  can  be  made  to  jump 
from  atom  to  atom  or  into  space.  Elements, 
such  as  iron,  aluminum,  copper  and  silver,  etc. 
are  good  conductors.  The  atomic  weights  are 
relatively  high,  and  there  are  a  larger  number 
of  electrons  per  atom.  This  gives  us  more  ac- 
tive or  floating  electrons  to  serve  as  current 
carriers,  but  in  all  cases  where  these  electrons 
are  charged,  they  are  called  negative  electrons. 
The  positive  electrons  are  not  detachable  from 
their  atom  base  or  centre.  If  by  chemical  or 
mechanical  means,  we  withdraw  some  of  these 


fig.  2 

Factors  in  condenser  ratings:  A — dielectric,  its  character 
and  thickness;  B — area  and  number  of  plates;  C — insula- 
tor; D — surfaces  opposed:  E — stray  fields 


432 


Radio  Broadcast 


negative  electrons  from  a  conductor,  such  as  a 
wire,  we  make  a  current  flow  because  there  is 
created  a  shortage  of  electrons  along  the  wire. 
The  actual  movement  of  the  electrons  is  not 
direct  along  the  wire.  The  electrons  are 
measured  in  billions  per  inch  of  wire  and  their 
normal  motions  are  very  erratic  so  that  a 
difference  in  potential  at  two  points  on  a  cir- 
cuit creates  only  an  "average"  movement  in 

*k   A 

a"  Hb 

FIG.  3 

Showing  the  gradient  of  current  pressure  (electron 
density)  on  a  wire.  At  A  the  electrons  are  excessive  and 
a  current  will  flow  to  B  until  the  common  level  is  on  line 
X.  The  density  is  obviously  a  "cone"  field  about  the 
wire,  but  for  purposes  of  simplicity  it  is  shown  only  as  a 
vertical  plane  above  the  wire 

one  direction.  This  may  be  illustrated  by  the 
movement  of  a  mob  of  people  about  a  theatre 
or  ball  park  entrance  who  may  push  and  jam 
toward  the  doors,  but  a  relatively  small  num- 
ber actually  pass  in,  during  a  given  interval  of 
time  although  the  average  or  "  net"  push  of  the 
crowd  can  be  tremendous,  especially  for  those 
who  happen  to  be  near  the  gates  or  wall.  The 
electrons  in  a  conductor  which  can  thus  be  used 
to  set  up  an  electric  current  are  termed  free 
electrons.  Their  speed,  or  average  movement, 
depends  upon  the  steepness  of  the  "grade" 
created  by  an  impressed  force  or  shortage  of 
electrons  created  at  any  point  (Fig.  3)  just  as  the 
speed  with  which  a  carwill  roll  down  hill  depends 
upon  the  slope  of  the  hill.  It  has  been  pointed 
out  that  approximately  only  one  in  5,000 
electrons  resident  in  a  conductor  actually  is 
used  when  a  current  is  flowing  through  the 
conductor.  In  conductors  the  electrons  are 
moving  in  all  directions  freely  and  wherever  an 
electron  dislodges  another  from  an  atom,  the 
space  left  by  the  dislodged  electron  is  filled  by 
another  electron  from  some  other  part  of  the 
conductor. 

In  non-conducting  materials,  so  called,  we 
have  electrons  which  relatively  are  not  free. 
They  are  so  tightly  bound  to  the  neutral  or 
centre  of  the  atom  that  only  extreme  pressures 
can  dislodge  them.  Such  materials  as  hard 
rubber,  air,  Formica,  Bakelite,  etc.  are  of  this 
type.  There  are  no  free  electrons  in  insulators 
although  electrical  pressure  can  be  applied  and 
its  effect  noticed  at  a  distance  in  the  insulator, 


much  in  the  same  manner  as  a  group  of  billiard 
balls  may  transmit  the  power  of  the  impact  of 
the  cue  ball  providing  a  group  of  balls  are 
already  in  physical  contact.  It  is  by  forcing 
them  out  of  their  normal  locations  that  we  can 
make  a  condenser  store  electrical  energy. 

THE    ACTION    OF    ELECTRONS    AT  CONDENSER 
PLATES 

ASSUME  that  a  potential  of  positive  polar- 
L  ity  is  applied  to  one  of  the  opposing 
plates.  That  means  that  one  wall  of  the  con- 
denser will  become  crowded  with  free  electrons 
and  the  other  wall  will  be  lacking  in  a  sufficient 
number  of  electrons  to  satisfy  the  atoms  in  the 
conducting  material  (Fig.  4).  Accordingly  there 
will  be  an  effect  transferred  to  the  dielectric  be- 
tween the  plates  which  is  an  electrostatic  strain 
or  displacement.  Although  the  electrons  of  the 
dielectric  are  not  free  to  move  permanently 
they  can  shift  out  of  place.  At  the  positive 
plate,  they  will  be  pushed  back  by  the  accumu- 
lation of  electrons  there.  At  the  negative  side 
they  will  be  pulled  toward  the  plate.  Yet  in 
neither  case  will  they  actually  move  out  of 
the  dielectric  to  the  conductor  or  out  of  the 
conductor  to  the  dielectric,  otherwise  the  cur- 
rent would  move  immediately  in  one  direction 
and  not  store  up  energy.  This  congestion  or 
concentration  of  the  electrostatic  strains  or 
lines  of  force  exerted  by  the  accumulation  of 
electrons  within  a  restricted  area  accounts  for 
the  term  "condenser." 


r~ 

f  v".:.''.'.  • . 

WALL  B 

\ '  : 

pf'-V  •■"  ■  ■ 

. .  . 

* 

§* 

DIELECTRIC — ' 

FIG.  4 

Condition  of  electron  congestion  of  a  charged  condenser. 
(The  dielectric  is  shown  as  a  separated  "unit"  in  the 
centre,  but  actually  is  in  contact  with  the  wall  surfaces  A 
and  B.)  The  stipling  illustrates  how  the  electrons  crowd 
up  on  the  inside  wall  of  the  A  plate,  thus  pushing  the 
dielectric  electrons  toward,  but  not  to,  the  B  plate,  where 
the  strain  causes  the  electrons  in  the  B  plate  to  move 
away  from  the  dielectric 


What  You  Should  Know  About  Condensers 


433 


/V  / 

|\            270'  2>60° 

0"    45*    90'  I80XJ 

FIG.  5 

Showing  how  a  counter  clockwise  rotating  voltage  or 
current,  or  both,  can  be  made  to  represent  a  "sine"  curve 
when  plotted  against  time.  Each  position  on  the  curve 
thus  has  an  "angular"  value,  used  constantly  in  mathe- 
matical calculation 

The  closer  the  conducting  walls  and  the 
greater  the  areas  of  their  opposing  surfaces, 
the  greater  their  capacity  to  ho  d  electrical 
energy.  A  condenser  cannot  exist  without  a 
dielectric  or  insulating  medium.  If  the  oppos- 
ing surfaces  are  separated  by  air,  air  is  the 
dielectric.  If  separated  by  mica,  then  mica  is 
the  dielectric.  The  dielectric  must  necessarily 
be  a  non-conductor.  This  explains  why  the 
electron  theory  is  vital  to  the  proper  under- 
standing of  condensers. 

The  dielectric,  therefore,  absorbs  a  certain 
amount  of  electricity  and  holds  it  in  suspension 
until  the  potential  used  to  move  the  free 
electrons  is  removed  or  reduced. 

When  the  condenser  walls  are  short  cir- 
cuited, the  stored  energy  is  permitted  to  dis- 
charge itself  and  a  current  is  set  up  in  an 
opposite  direction  to  that  of  the  original  charge. 
Note  that  there  are  thus  two  currents:  the  cur- 
rent of  free  electrons  in  the  conductor  and  the 
current  of  the  movable  but  restricted  electrons 
in  the  dielectric.  The  first  is  a  conduction  cur- 
rent and  the  second  a  displacement  current. 
This  distinction  is  fundamental. 

If  the  impressing  electromotive  force  (the 
push  or  pull  of  electrons  along  the  circuit)  is 
great,  it  may  cause  such  a  strain  upon  the 
electrons  in  the  dielectric  that  the  free  electrons 
will  break  through  the  dielectric  and  flash  as 
a  spark  discharge,  in  which  case  they  pass  phys- 
ically through  the  dielectric  whether  it  be  glass, 
air,  mica  or  what  not  and  actually  "puncture" 
the  insulating  medium.  Thus  storm  clouds 
accumulate  electric  potentials  which  are  built 
up  until  they  are  so  great  that  they  break  down 
the  insulation  of  the  air  and  lightning  is  dis- 
charged from  cloud  to  cloud  or  to  the  ground. 

In  radio  receiving  circuits  we  are  dealing  with 
extremely  small  voltages,  so  minute  that  it  is 
practically  impossible  to  construct  a  condenser 
with  walls  so  close  together  that  a  spark  could 


be  passed  by  the  voltage  set  up  from  a  received 
signal.  The  "puncture  voltage"  of  a  receiving 
condenser  is  therefore  not  important.  (Static 
charges,  however,  even  on  small  aerials,  will 
build  up  potentials  of  a  thousand  volts  or 
more  and  cause  considerable  sparking  across 
the  condenser  walls.)  It  is  of  vital  impor- 
tance, however,  to  preserve  all  the  variations 
in  voltage  and  current  of  the  received  signal 
regardless  of  how  weak  it  may  be.  This 
involves  certain  resistance  effects  of  high- 
frequency,  alternating  currents,  and  only  by 
understanding  them  can  we  appreciate  the 
importance  of  correct  condenser  design. 

CAPACITY,   INDUCTANCE,  AND  RESISTANCE 

EVERY  alternating  current  circuit  exhibits 
three  properties  in  variable  proportions. 
There  will  be  some  capacity,  some  resistance 
and  some  inductance  regardless  of  whether 
they  are  wanted  or  not.  We  find,  also,  that 
every  circuit  will  respond  or  be  most  easily 
disturbed  by  an  alternating  current  of  one 
definite  frequency  more  readily  than  by  any 
other  frequency.  The  frequency  may  be  ten 
oscillations  (charges  and  discharges)  of  the 
current  through  the  circuit  in  one  second,  or 
it  may  be  one  million  oscillations  in  one  second. 

An  excellent  anology  may  be  drawn  from  the 
use  of  a  tuning  fork  (Fig.  8).  If  struck,  it  vibrates 
and  emits  a  note.  The  tines  thus  represent 
three  physical  effects:  (i)  the  compression 
swing  which  we  may  call  the  condenser,  (2) 
the  inertia  pull  at  the  end  of  each  swing  which 
is  typical  of  the  inductance  drag,  and  (3)  the 
air  resistance  equal  to  the  circuit  resistance. 
If  the  fork  is  put  in  a  sealed  tube  and  the  ah 
pumped  out,  the  fork  will  oscillate  for  a  much 


0  F  FREQUENCY 


FIG.  6 

Reactance  curves,  showing  how  the  capacitative  react- 
ance and  the  inductive  reactance  are  neutralized  at 
resonance,  shown  at  point  F 


434 


Radio  Broadcast 


fig.  7 

Condition  of  electron  displacement  in  the  die- 
lectric on  one  phase  in  an  alternating  current 


longer  period  although  no  sound  can  be  heard 
from  it.  The  frequency  with  which  the  fork 
vibrates  depends  upon  the  length,  weight  and 
elasticity  of  the  tines. 

If  we  mount  two  tuning  forks  of  the  same 
frequency  on  a  board,  we  can  strike  one  and 
its  vibrations  carried  through  the  air  or  along 
the  board  will  cause  the  second  fork  to  begin  to 
vibrate.  This  is  due  to  the  fact  that  a  slight 
disturbance  of  the  same  frequency  as  that  of 
the  fork  causes  it  to  vibrate  and  if  the  dis- 
turbance is  prolonged,  the  two  forks  vibrate 
continuously  for  some  time. 

If,  therefore,  we  wish  to  secure  a  signal  from 
a  certain  station,  we  adjust  our  receiving  cir- 
cuit so  that  it  will  oscillate  or  alternate  in  po- 
tential and  current  with  the  exact  frequency  of 
the  wave  used  by  the  transmitter.  Then  any 
variation  in  the  amount  of  current  sent  from 
the  transmitting  antenna  and  to  the  receiving 
circuit  is  acting  upon  a  highly  sensitive  mechan- 
ism which  is  so  critically  balanced  that  it  will 
oscillate. 

In  this  resonant  circuit  we  must  hold  the 
resistances  down  in  every  way.  Hence,  we  will 
return  to  the  condenser  part  of  the  circuit  and 
limit  the  discussion  to  a  definite  range  of 
frequencies. 

For  wavelengths  of  220  meters  we  are  detect- 
ing currents  that  alternate  at  1,363,500  alterna- 
tions per  second.  For  waves  up  to  700,  the 
frequency  is  down  to  428,600  alternations  per 
second.    For  350  meters  our  condenser  must 


charge  and  discharge  857,100  times  a  sec- 
ond. 

LOSSES    IN  CONDENSERS 

THE  first  thing  we  observe  when  a  con- 
denser is  used  in  a  high-frequency  circuit 
is  that  the  current  may  be  dissipated  in  the 
dielectric.  Thus,  if  we  force  1  ampere  of 
current  into  a  condenser  and  when  it  discharges 
we  only  get  back  .9  amperes,  there  has  been  a 
dielectric  loss  of  .  1  amperes  due  to  the  creepage 
across  the  space  between  the  plates.  Some  of 
the  current  must  have  "leaked"  through  the 
dielectric  or  have  been  absorbed  in  the  dielectric 
itself.  These  losses  are  normally  too  small  to 
measure  when  the  dielectric  is  only  dry  air,  but 
under  certain  conditions  the  leakage  can  in- 
crease to  an  appreciable  extent.  In  a  solid 
dielectric,  this  loss  is  always  appreciable  and 
accounts  in  one  way  for  the  preference  of  radio 
engineers  in  using  air  as  a  dielectric  wherever 
possible 

fig.  8 

When  the  tuning  fork  is  moving  as  in  A,  its  spring  is  com- 
pressing, but  its  momentum  is  decreasing.  In  B,  its 
spring  is  released  and  the  momentum  forces  the  lines  to 
swing  outward  and  accumulate  an  opposite  spring  ten- 
sion. In  C,  the  momentum  and  the  spring  effects  are 
at  the  neutralized  point  where  spring  effect  equals  mo- 
mentum, and  the  direction  of  motion  changes  with  the 
spring  effect  inward  exceeding  the  momentum  outward. 
Any  piece  of  steel  or  other  springy  material  has  a  natural 
period  of  vibration  just  as  an  electrical  circuit 


The  second  and  final  pari  of  this  article  will  appear  next  month.  It  will  deal  with  furihe; 
kinds  of  losses  in  condensers,  variable  air  condensers  for  radio  use,  disadvantages  of  the  conven- 
tional form  of  condenser,  the  best  materials  for  condensers,  and  condenser  ratings. 


The  Grid 


QUESTIONS  AND  ANSWERS 

The  Grid  is  a  Question  and  Answer  Department  maintained  especially  for  the  radio  amateurs.  Full 
answers  will  be  given  wherever  possible.  In  answering  questions,  those  of  a  like  nature  will  be  grouped 
together  and  answered  by  one  article.  Every  effort  will  be  made  to  keep  the  answers  simple  and  direct, 
yet  fully  self-explanatory.  Questions  should  be  addressed  to  Editor,  "  The  Grid,"  Radio  Broadcast, 
Garden  City,  N.  Y. 


Adapting  your  three-circuit  Receiver  to  the  New 
wavelengths 

THE  allotment  of  higher  waves  to  broadcasting  stations 
has  made  necessary  the  loading  of  many  receivers  in 
order  to  preserve  efficient  reception  over  the  entire 
wave  range.  The  majority  of  enthusiasts  have  found  it  a 
comparatively  simple  matter  to  load  up  the  single-circuit 
sets.  Generally  their  own  ingenuity  has  pointed  out  the 
necessity  of  adding  merely  a  few  more  turns  of  wire  to  the 
main  inductance.  The  wave  shift  with  the  honeycomb 
sets  is  less  complicated  and  is  effected  by  using  slightly 
larger  coils  in  primary,  secondary,  and  if  necessary,  in  the 
tickler. 

The  variocoupler-twin-variometer  set,  however,  presents 
somewhat  of  a  problem,  and  Radio  Broadcast  has  been 
the  recipient  of  numerous  inquiries  as  to  the  most  efficient 
method  of  loading  apparatus  of  this  type. 

There  are  two  basic  ways  in  which  this  may  be  accom- 
plished: by  the  addition  of  inductance,  and  by  the  addition 
of  capacity.  The  first  method  is  perhaps  the  most  efficient 
and  at  the  same  time  most  simple.  The  loading  coil  con- 
sists of  ten  turns  of  wire  on  a  two  and  a  half  inch  diameter 
tube  (or  simply  wound  about  the  fingers),  inserted 
in  series  with  the  grid  variometer  and  secondary,  as  is 
shown  in  Fig.  i.    A  small  panel  switch  is  included  across 


TO  GRID 


FIG.  I 

A  loading  coil — 10  turns  of  wire  on  a  25-inch  tube, 
raises  the  wavelength  of  the  secondary  circuit. 
If  the  antenna  is  a  fairly  long  one,  it  is  generally 
unnecessary  to  load  the  primary  circuit 

the  extra  inductance  for  shorting  during  short-wave  recep- 
tion. The  loading  coil  may  be  placed  within  the  cabinet, 
care  being  taken  to  locate  it  in  such  a  manner  that  it  is  not 
in  inductive  relation  (near  and  parallel)  to  other  coils  of  the 
set.  If  placed  too  near  other  inductances,  the  load  may 
absorb  energy  when  shorted  and  lessen  the  general  efficiency 
of  the  apparatus. 

The  addition  of  a  small  capacity  across  the  secondary 
of  the  variocoupler  and  the  grid  variometer  (Fig.  2)  will 
also  boost  the  wave  well  above  the  broadcasting  frequen- 
cies, and  into  the  path  of  six  hundred  meter  traffic,  a  wave- 


FIG.  2 

A  small  condenser,  C,  across  the  secondary  of  the 
variocoupler  and  the  grid  variometer  will  also 
raise  the  wavelength  of  the  secondary  circuit 

length  worth  investigating  by  enthusiasts  mastering  tht 
code.  The  condenser  is  most  easily  made  from  a  standard 
.0005  grid  condenser  (minus  the  leak),  by  unrolling  and 
clipping  off  one  half  of  the  copper  foil,  and  firmly  rebinding 
the  remaining  foil  and  waxed  paper.  A  switch  is  again 
provided  for  eliminating  the  condenser  on  waves  which 


FIG.  3 

1  his  system  of  capacity  load  permits  a  wide  tuning  range 
— from  the  amateur  wavelengths  up  to  about  1000  meters 


436 


Radio  Broadcast 


fig.  4 

Here  a  loop  antenna,  shunted  by  a  variable  con- 
denser, is  substituted  for  the  outdoor  antenna, 
ground  and  variocoupler  of  the  standard  receiver 

can  be  received  with  the  variocoupler  and  variometer 

a'<  ne. 

A  second  system  of  capacity  load,  which  is  used  by  a 
well-known  manufacturer  of  variometer  receivers,  is  shown 
in  Fig.  3.  This  system  enables  the  operator  to  proceed  in 
overlapping  jumps  from  short  waves  (up  to  four  hundred 
and  fifty  meters)  to  medium  waves  (in  the  neighborhood  of 
six  hundred),  and  high  waves  (up  to  one  thousand  meters), 
by  the  three  different  positions  (right,  open,  and  left)  of  a 
double-pole  double-throw  switch.  The  extra  capacities,  C 
and  C1,  may  be  made  in  the  same  manner  as  that  for  the  cir- 
cuit shown  in  Fig.  2,  except  that  only  one  third  of  the  foil  is 
cut  from  the  standard  condenser.  This  is  due  to  the  fact  that 
on  medium  waves,  the  condensers  are  in  series,  which  gives 
a  total  extra  capacity  across  the  variometer  and  secondary, 
of  one  half  that  of  a  single  condenser.  On  the  thousand 
meter  adjustment,  the  capacity  (one  condenser)  is  increased 
across  the  grid  circuit,  while  the  remaining  condenser  cou- 
ples the  grid  and  plate  elements  of  the  tube,  maintaining 
regeneration  by  capacity  feed-back  over  the  entire  scale  of 
wavelengths. 

Using  an  aerial  of  generous  proportions,  it  is  seldom 
necessary  to  load  the  primary  circuit.  However,  if  follow- 
ing the  instructions  given  in  the  preceding  paragraphs  avails 
little  improvement  on  the  higher  waves,  a  small  load 
(about  ten  turns  of  wire  on  a  three-inch  tube)  should  be 
placed  in  series  with  the  antenna,  and  provided  with  the 
usual  short-circuiting  switch. 

Some  readers  have  found  it  difficult  to  receive  the  higher 
wavelengths  on  the  set  described  by  Mr.  Seager  in  the 
March  Radio  Broadcast.  This  difficulty  is  very  easily 
remedied  by  adding  eight  turns  of  wire  to  the  primary,  and 
ten  tiwns  to  the  secondary,  adding  the  wire  in  each  case 
between  the  last  two  high-wave  taps.  That  is,  if  at  present 
there  are  twelve  turns  of  wire  between  the  last  two  (on  the 
high  end)  primary  taps,  there  will  be  twenty  turns  after 
the  addition  of  the  extra  inductance.  If  the  set  does  not 
oscillate  with  the  additional  turns  in  the  circuit,  it  will  be 
necessary  to  shunt  the  tickler  with  a  small  condenser 
(similar  to  that  described  for  use  in  Fig.  2)  with  a  switch 
for  disconnecting  it. 

Substituting  Loops  on  Standard  Receivers 

/  was  much  interested  in  Mr.  Herts' s  article  on  adding  two 
steps  to  an  Aeriola  Sr.,  in  the  May  number  of  Radio  Broad- 
cast. Mr.  Herts  said  that  he  used  a  loop  on  this  set.  In 
common  with  your  other  numerous  readers,  I  should  he 
obliged  if  you  would  show  Mr.  Herts' s  hook-up  using  a  loop. 

J.  W.  T.  P..  Truro,  Nova  Scotia. 


ANY  circuit  operating  from  an  open  antenna  can  be  suc- 
cessfully converted  for  loop  reception  providing  that 
^  the  nearness  of  broadcasting  stations  or  the  presence 
of  radio-frequency  amplification  justifies  the  change.  It  will 
merely  be  necessary  to  rearrange  the  grid  circuit,  elimina- 
ting the  original  tuning  apparatus,  and  replace  it  by  the 
loop  with  a  shunted  condenser,  as  per  the  diagram  in  Fig.  4. 
The  notable  exception  to  this  procedure  is  the  tickler 
regenerative  circuit,  which  is  not  well  adapted  to  loop  recep- 
tion due  to  the  necessity  of  introducing,  in  series  with  the 
loop,  a  separate  load  with  a  tickler,  thus  cutting  down  the 
number  of  turns  active  in  the  picking  up  of  radio  signals. 

In  the  circuit  to  which  j.  W.  T.  P.  refers,  the  loop  will 
.be  substituted  for  the  first  variometer,  and  the  series 
condenser  placed  in  shunt  with  it — in  other  words,  as  shown 
in  Fig.  4. 

Antenna  Corrosion  and  Resistance 

/  have  read  that  an  aerial  should  be  re-wired  every  year 
or  so,  due  to  the  fact  thai  the  surface  corrodes,  increasing  its 
resistance  to  high-frequency  radio  currents  which  I  am  also 
informed  travel  on  the  surface  of  the  wire.  {Why  is  this?) 
My  antenna  has  been  up  nine  months,  and  the  signals  of  late 
seem  weaker  than  usual.  Do  you  think  that  it  is  due  to  sur- 
face corrosion? 

M.  A.  C,  Albany,  N.  Y. 

LOSS  of  signal  strength  in  the  above  case  is  doubtless 
due  o  some  cause  other  than  that  which  the  writer 
■J  suggests.  It  is,  however,  quite  possible  that  cor- 
rosion or  oxidization  at  unsoldered  joints,  if  such  exist  in  his 
,-ntenna,  has  become  so  far  advanced  as  to  almost  cut  off 
or  completely  isolate  certain  portions  of  his  aerial  system. 
.  The  decrease  in  loudness  due  to  surface  variations  of 
the  wire  is  seldom  sufficient  to  be  noticeable.  Before 
this  stage  is  reached,  the  wire  generally  weakens  in  one 
or  more  places  and  breaks.  The  voltage  drop  which  our 
communicant  suggests  is  due  to  resistance  (as  are  practi- 
cally all  electrical  and  mechanical  losses),  and  the  loss  is 
at  all  times  proportional  to  the  strength  of  the  current. 
As  the  eceived  energy  is  minute  in  the  extreme,  it  follows 
that  the  current  would  not  be  sufficiently  strong  to  occa- 
sion a  perceptible  loss. 

High-frequency  currents,  such  as  radio  oscillations,  tend 
to  travel  on  the  surface  of  the  wire  due  to  a  phenomenon 
known  as  "surface"  or  "skin  effect",  the  study  of  which 
takes  one  quite  deeply,  but  interestingly,  into  the  science 
of  high-frequency  alternating  currents. 

The  path  or  wire  of  all  electric  currents  is  surrounded 
by  a  magnetic  field  which  varies  in  intensity  as  the  current 
strengthens  or  weakens.  When  the  amperage  (measure 
of  current)  rises,  the  magnetic  field  spreads  out  farther 
from  the  wire — when  it  drops,  the  magnetic  field  contracts. 
In  alternating  electricity  the  strength  of  the  current  is 
constantly  varying  from  zero  to  maximum.  Hence  it  goes 
without  saying  that  the  resulting  magnetic  field  is  continu- 
ally jumping  in  and  out  from  the  wire,  totally  disappearing 
into  the  centre  of  the  wire  from  which  it  apparently  springs, 
when  the  current  is  at  zero. 

Whenever  a  moving  magnetic  field,  such  as  that  expand- 
ing and  contracting  about  a  wire  carrying  alternating  cur- 
rent, cuts  another  conductor,  electricity,  or  a  current,  is 
"induced"  therein.  This  is  merely  the  theory  of  the 
dynamo  which  is  nothing  more  than  a  machine  for  cutting 
a  conductor  by  a  magnetic  field. 

The  current  induced  in  a  conductor  by  a  near-by  alter- 
nating current  is  in  a  direction  always  opposite  to  that  of  the 


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original  current.  But,  as  mentioned  before,  the  magnetic 
lines  of  force  apparently  emanate  from  the  infinite  dead 
centre  of  the  wire.  It  would  then  follow  that,  in  expand- 
ing, they  must  cut  the  wire  itself,  and  induce  therein  a 
current  always  opposing  the  current  that  induces  it!  This 
is  precisely  what  occurs,  and  in  every  alternating  current 
line  there  is  a  counter  electro-motive  force  that  tends  to 
buck  or  stop  the  first  current.  (This  is,  of  course,  not 
the  counter  E.  M.  F.  (electro-motive  force)  generally  re- 
ferred to  in  an  inductive  circuit.) 

In  expanding  out  of  the  wire,  or  in  contracting  back  into 


the  wire,  more  lines  of  force,  in  a  given  time,  cut  the  centre 
and  the  inside  of  the  wire  than  cut  the  surface.  This  is  neces- 
sarily so,  because  some  of  the  lines  never  expand  so  far  as 
the  surface.  In  other  words,  this  counter  E.  M.  F.  is 
greater  at  the  centre  of  the  wire  than  at  its  surface,  and  the 
surface  being  the  less  opposed  and  freer  path,  is  taken  by 
the  current! 

This  skin  effect,  however,  is  only  noticeable  with  high- 
frequency  currents. where  the  field  expands  and  contracts 
many  thousands  of  times  a  second,  and  the  "centre  op- 
position" is  practically  constant. 


Supplemental  List  of  Broadcasting  Stations  in  the  United  States 

LICENSED  FROM  JUNE  16  TO  JULY  13  INCLUSIVE 


WAVE- 
LENGTH 


CALL 
SIGNAL 


FREQUENCY 

( Kilocycles) 


KFHS  Nelson,  Robert  Washington,  Hutchinson,  Kansas  . 

KFHU  Sateren,  M.  G.,  Mayville,  N.  D  

KFHY  Mc  Ewan,  R.  S.,  Trinidad,  Col.  ...  .... 

KFIU  Alaska  Elect.  Light  &  Power  Co.,  Juneau,  Alaska 

KFIV  Broyles,  V.  H.,  Pittsburg,  Kansas  

KFIX  Reorganized  Church  of  Jesus  Christ,  Independence,  Kansas. 

WCAP  Chesapeake  &  Potomac  Tel.  Co.,  Washington,  D.  C.   .  . 

WKAD  Looff,  Charles  E.,  Providence,  R.  I  

WRAZ  Radio  Shop  of  Newark,  Newark,  N.  J  

WSAG  Davis,  Loren  V.,  St.  Petersburgh,  Fla  

WSAK  Daily  News,  The,  Middleport,  Ohio  

WSAN  Allentown  Radio  Club,  Allentown,  Pa  

WSAQ  Round  Hills  Radio  Corp.,  Dartmouth,  iVlass.        .     .  . 

WSAR  Doughty  &  Welch  Elect.  Co.,  Fall  River,  Mass.    .    .  . 

WTAB  Fall  River  Daily  Herald,  Fall  River,  Mass  


13 10 

229 

1 1 50 

26l 

1240 

242 

1330 

226 

1250 

24O 

1250 

24O 

640 

469 

1250 

24O 

1290 

233 

1230 

244 

1 160 

258 

1310 

229 

1070 

280 

1 180 

254 

I2IO 

248 

DELETIONS  FROM  JUNE  1  TO  JUNE  30 


KDZG    .    .    .  . 

San  Francisco,  Calif. 

WGAM       .    .  ■  . 

.    Orangeburg,  S.  C. 

KDZX    .    .     .  . 

San  Francisco,  Calif. 

WHAE  .    .    .  . 

Sioux  City,  Iowa 

KFBD    .    .     .  . 

Hanford,  Calif. 

WHAW  .     .    .  . 

Tampa,  Fla. 

KFBH    .     .     .  . 

.     .     Marshfield,  Ore. 

WIAE    .     .     .  . 

Vinton,  Iowa 

KFCB    .    .    .  . 

Phoenix,  Ariz. 

WKAH  .    .    :  ; 

KFEB    .     .    .  . 

.     .     .    Taft,  Calif. 

WKAK  .    .    .  . 

.     .     .    Okemah,  Okla. 

KFGB    .     .    .  . 

Pueblo,  Colo. 

WKAL  .     .    .  . 

Orange,  Texas 

KJJ       .    .    .  . 

Sunnyvale,  Calif. 

WKN     .    .     .  . 

Memphis,  Tenn. 

KNI       .    .     .  . 

Eureka,  Calif. 

WLK     .    .     .  . 

Indianapolis,  Ind. 

KNN     .    .    .  . 

Los  Angeles,  Calif. 

WMAG  .    .     .  . 

Liberal,  Kansas 

KOA      .    .    .  . 

Denver,  Colo. 

WMAR      .    .  . 

Waterloo,  Iowa 

KSL      .     .    .  . 

San  Francisco,  Calif. 

WMAX  .    .    .  . 

.    Ann  Arbor,  Mich. 

WAAL   .    .    .  , 

Minneapolis,  Minn. 

WOAS    .     .     .  . 

Middletown,  Conn 

WAAY  .    .     .  . 

Youngstown,  Ohio 

WOAU  .    .    .  . 

Evansville,  III. 

WCAB        .    .  . 

.    Newburgh,  N.  Y. 

WOU     .    .    .  . 

Omaha,  Neb. 

WCAC       .    .  . 

Fort  Smith,  Ark. 

WPAA   .     .    .  . 

..    .    Wahoo,  Neb. 

WCAW       .    .  . 

Quincy,  111. 

WPAY        .    .  . 

Bangor,  Maine 

WCN     .    .    .  . 

Worcester,  Mass. 

WPE     .    .    .  . 

Independence,  Mo 

WEAV       .    .  . 

.    .    .    Rushville,  Neb. 

WPO     .     .     .  . 

Memphis,  Tenn. 

WEAX  .    .    .  . 

.     .    .    Little  Rock,  Ark. 

WRAC  .     .     .  . 

.    .     .    Mayville,  N.  D. 

WEH     .    .    .  . 

Tulsa,  Okla. 

WRAK  .     .    .  . 

WEY     .    .    .  . 

Wichita,  Kansas 

WRAM       .    .  . 

Galesburg,  III. 

WFAC   .    .    .  . 

Superior,  Wis. 

WSAV    .     .     .  . 

Houston,  Tex. 

WFAW  .    .     .  . 

.     .    Miami,  Fla. 

WWAY       .     .  . 

Chicago,  III, 

WFAZ    .    .    .  . 

.    Charleston,  S.  C. 

"Roxie's"  Own  Story 


Published  by  DOUBLEDAY,  PAGE  85  CO.  Garden  City,  N.  Y. 


Carries  Great  Messages 
Around  the  World 

THAT  statement  adequately  expres  es  what  is  perhaps  the 
greatest  influence  of  radio  in  developing  and  bettering  human 
fraternal  interest,  not  only  between  people  of  one  community, 
of  one  country,  of  one  state,  or  even  a  single  nation,  but  be- 
tween all  nations  and  all  peoples  of  the  world. 

Be  these  messages  from  government  leaders — from  the  heads  of 
the  world's  greatest  educational  institutions  or  from  those  who  stand 
foremost  in  the  arts  of  the  world — they  will  serve  to  bring  the 
human  race  into  closer  contact. 

In  the  past  ages  great  orators  and  writers,  famous  poets  and  mu- 
sicians have  swayed  the  destinies  of  nations,  and  have  been  instru- 
mental in  the  rise  and  downfall  of  mighty  empires. 

In  the  future  these  same  influences  of  similar  great  minds  will, 
through  radio,  create  a  better  understanding  and  a  greater  fraternal 
spirit  between  the  people  of  the  nations. 

It  is  the  vacuum  tube  that  has  made  possible  this  broad  and  far 
reaching  application  of  radio  telephony,  and  that  plays  the  most  im- 
portant part  in  the  operation  of  your  receiving  set. 

Cunningham  Vacuum  Tubes,  standard  for  all  makes  of  receiving 
sets — built  by  one  of  the  world's  largest  manufacturers  with  un- 
limited resources — are  the  product  of  years  of  manufacturing  expe- 
rience and  the  creative  genius  of  the  engineers  of  that  great  scientific 
organization,  the  Research  Laboratory  of  the  General  Electric 
Company. 


Cunningham  Radio  Tubes 

C-301A — 6  Volts  Vi  amp. 
Amplifier   ?6.50 

C-2  9  9 — 3  Volts  .0  6  amp. 
Dry  Battery  D?t.  & 
Amp   6.50 

C-300 — f>  Volts  Gas  Con- 
tent Detector    5.00 

C-ll — 1.1  Volts  .25  amp. 
Dry  Battery  Det.  and 
Amp.  Special  Base...  6.50 

C-12 — Similar  to  C-l  1 
with  standard  base.  .  .   6.5  0 


Patent  Notice: 

Cunningham  tubes  are  covered  by  pat- 
ents dated  1  1-7-05,  1-15-07,  2-18-OJJ, 
and  others  issued  and  pending.  Li- 
censed for  amateur,  experimental,  and 
entertainment  use  in  radio  communi-a- 
tions.  Any  other  use  will  be  an  in- 
fringement. 


CUNNINGHAM 
National 
Tube  Week 

September  24  to 
October  1,  1923 

$5000  in  Cash  Prizes 
to  Radio  Dealers 


Home  Office: 

248  First  Street 
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■j(  Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


A  Highly  Efficient 
Set  at  a  Moderate  Price 


Here  is  an  inexpensive  set  that  receives  sig- 
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The  low  cost  of  this  set  in  addition  to  its 
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ic  Tested  and  approved  by  Radio  Broadcast  + 


Radio  Broadcast 


ARTHUR  H.  LYNCH,  Editor 


CONTENTS  FOR  OCTOBER,  1923 

Major-General  George  0.  Squier   -    --    --    --    --    --    --    --    -  Frontispiece 

THE  MARCH  OF  RADIO-    --------------- J.  H.  M.  447 

A  BIT  ABOUT  MYSELF  ("Roxie")  S.  L.  Rothafel  458 

GIVING  THE  PUBLIC  A  LIGHT-SOCKET  BROADCASTING  SERVICE 

William  Harris,  Jr.  465 

WHEN   THE  BUG  BIT  IN  SAMOA     --------    Quincy  F.  Roberts  471 

IN  THE  WAKE  OF  THE  CONTEST  WINNERS  -----------  477 

A  Better  Broadcast  Receiver    -    -    -    -  (Honorable  Mention)  Arthur  L.  Munzig  477 

A  Set  You'll  Like  To  Make      -----     (Honorable  Mention)  Frank  Nelem  480 

A  Set  With  a  Tuned  R.  F.  Amplifier  -    -    -    (Honorable  Mention)  J.  W.  Denning  484 

A  Home-Made  Three-Tube  Outfit  -    -----    (Honorable  Mention)  L.  Reith  486 

Summary  of  Receiving  Contest  Entries  -    --    -   ^gg 

A  NEW  STATION  AT  WASHINGTON,  D.  C.  -    -    -    -    -     Pierre  Boucheron  494 

RHEOSTATS  FOR  THE  TUBES  YOU  USE     --------    -  Zeh  Bouck  496 

WITH  MacMILLAN  AND  RADIO,  NORTH  OF  CIVILIZATION 

E.  F.  McDonald,  Jr.  500 

WHAT  BALLOON  RACERS  DID  WITH  RECEIVING  SETS  -    -    -----    -    -  507 

WHAT  YOU  SHOULD  KNOW  ABOUT  CONDENSERS,  II     Allen  D.  Cardwell  510 

TRUE  PIANO  MUSIC  FROM  A  NEW  MICROPHONE  ---------  516 

WHAT  OUR  READERS  WRITE  US    ---------------  517 

IN  THE  R.  B.  LAB.     --------------------  520 

ADDITIONAL  BROADCASTING  STATIONS  IN  THE  UNITED  STATES-    -    -  523 

NEW  EQUIPMENT  ---------------------  524 

THE  GRID — Questions  and  Answers  -    --    --    --    --    --    --    --    -  526 

AMONG  OUR  AUTHORS  ------  -   -    -   -    -    -   -  534 

Copyright,  1923,  by  Doubleday,  Page  &  Co.    All  rights  reserved 
TERMS:  $3.00  a  year;  single  copies  25  cents 
F.  N.  Doubleday,  Pres.  Arthur  W.  Page,  Vice-Pres.  Nelson  Doubleday,  Vice-Pres. 

Russell  Doubleday.  Sec  y.  S.  A.  Everitt,  Treas.  John  J.  Hessian,  Asst.  Treas. 

DOUBLEDAY,  PAGE  &  CO. 

The  World's  Work       Country  Like      The  Garden  Magazine      Short  Stories       Educational  Review 
CHICAGO:  People's  Gas  Bldg.  GARDEN  CITY,  N.  V.  [  NEW  YORK:  120  W.  32nd  Street 

BOSTON:  Tremont  Bldg.  LOS  ANGELES:    Van  Nuys  Bldg 


RADIO  BROADCAST  ADVERTISER 


is  used  in  the  new 

Freed-Eisemann 

N  R  Neutrody tie  Receiver 

THE  panels  of  the  new  Freed-Eisemann  Neutrodyne  Re- 
ceiver are  Formica.  This  is  natural  because  Freed- 
Eisemann  have  long  been  consistent  users  of  Formica  in  all 
their  past  radio  products. 

It  is  the  endorsement  of  leading  radio  concerns  of  this 
caliber  from  one  end  of  the  country  to  the  other  that  makes 
Formica  so  staple  and  desirable  a  product  for  the  radio 
dealer  to  handle.    Amateurs  know  and  want  it. 

Formica  panels  may  be  had  promptly  in  any  desired  size. 
It  isn't  necessary  to  take  a  size  that  some  one  else  wants 
to  sell. 

THE  FORMICA  INSULATION  COMPANY 
4628  Spring  Grove  Avenue       Cincinnati,  Ohio 


50  Church  St.  New  York,  N.  Y. 
422  First  Ave.  Pittsburgh,  Pa. 

1042  Granite  Bldg.,  Rochester,  N.  Y. 
415  Ohio  Bldg.  Toledo,  Ohio 

Reg.  U.  S.  Pat.  Off. 


Sales  Offices 

1210  Arch  St.                 Philadelphia,  Pa.  414  Finance  Bldg.,  Cleveland,  Ohio 

1819  Lyndale  Ave.,  S.  Minneapolis,  Minn.  9  S.  Clinton  St.              Chicago,  ZU. 

Sheldon  Bldg.     San  Francisco,  California  313  Title  Bldg.          Baltimore,  Md. 

Whitney  Central  Bldg.          New  Orleans  47  King  St.            Toronto,  Ontario 


ORMICA 

Made  from  Anhydrous  Redmanol  Resins 
SHEETS    TUBES  RODS 


■fa  Tested  and  approved  by  Radio  Broadcast 


MAJOR-GENERAL  GEORGE  OWEN  SQUIER 
Chief  Signal  Officer  of  the  U.  S.  Army,  whose  experiments  in  "wired  wireless"  have  made  possible  a  practicable,  paying 
service  which  will  furnish  "subscribers"  with  news,  entertainment,  and  educational  matter.    Such  a  service  is  already 
being  successfully  operated  on  Staten  Island,  N.  Y.  (See  page  465) 


Vol. 


RADIO 
BROADCAST 


No.  6 


October,  1923 


The  March  of  Radio 

OCEAN  TO  OCEAN  BROADCASTING 


A  LTHOUGH  it  is  not  to  be  expected  that 
i\  developments  in  radio  will  rush  to 
/  %  greet  us  every  month  (for  it  is  bound 
/  %  to  happen,  now  and  then,  that 
radio,  like  any  other  development, 
marks  time),  nevertheless  several  of  the  events 
which  came  to  our  attention  during  the  past 
month  do  indicate  the  orderly  progress  of  the 
art.  Especially  is  this  the  case  with  the  plans 
made  for  the  role  which  radio  was  to  play  on  the 
night  when  our  late  President  was  scheduled 
to  address,  personally,  an  audience  in  the  Civic 
Auditorium  in  San  Francisco,  and,  by  land  lines 
and  radio,  another  audience  "measured  in  the 
millions."  We  get  so  used  nowadays  to  hear- 
ing of  radio  audiences  measured  in  millions, 
that  such  an  announcement  scarcely  arouses 
interest;  but  in  this  case  it  should,  because  this 
prospective  audience  undoubtedly  was  of  this 
size.  It  is  so  easy  to  say  that  at  least  one 
person  out  of  a  hundred  in  our  country  must  be 
listening  in  on  a  radio  set,  and  that,  inasmuch 
as  there  are  a  hundred  million  people  in  the 
land,  the  audience  must  be  a  million ! 

It  is  extremely  doubtful  if  an  audience  of  a 
million  persons  had  ever  been  possible  before 
this  demonstration  was  arranged.  The  audi- 
ence which  would  have  listened  to  the  President, 
had  not  his  fatal  illness  prevented  it,  was  not  to 
have  been  the  clientele  of  one  station — there 
were  to  have  been  six  broadcasting  stations, 
from  Coast  to  Coast,  actuated  simultaneously  by 
the  President's  voice.  To  think  of  a  low,  well- 
modulated  voice  being  thrown  out  into  the  air 


at  such  strategic  points  that  it  is  heard  at  the 
same  instant  over  the  whole  land — one  man 
quietly  addressing,  intelligibly,  a  million  of  his 
fellows!  In  the  olden  days  it  required  no  such 
feat  as  that  to  be  classed  as  a  miracle. 

If  this  plan  had  gone  through,  a  peculiar 
effect  might  have  been  observed  by  an  experi- 
menter located  somewhere  about  the  middle  of 
our  country.  The  transcontinental  telephone 
line,  over  which  the  voice  currents  were  to 
travel  to  actuate  the  stations  on  the  Eastern 
Coast,  is  partly  of  the  "loaded  type."  To 
keep  the  voice  currents  from  being  wasted  to 
an  excessive  degree  as  they  take  their  long 
journey  it  is  necessary  to  put  iron-cored  coils  in 
series  with  the  wires  at  regular  intervals — 
every  few  miles  for  overhead  lines  and  every 
mile  for  cables.  The  electric  current  travels 
over  such  a  loaded  line  less  rapidly  than  it  does 
over  a  pair  of  ordinary  overhead  wires.  For 
two  copper  wires,  supported  on  poles  by  good 
insulators,  the  speed  of  the  signal  is  practically 
the  same  as  that  of  light — 186,000  miles  a 
second.  In  the  loaded  Tine,  however,  the  coils 
slow  down  the  current  to  the  extent  that  it 
takes  about  one-fifteenth  of  a  second  for  the 
signal  to  travel  from  San  Francisco  to  New 
York.  If,  then,  a  listener  with  a  good  set, 
located  about  half  way  between  these  two 
points,  should  be  able  to  tune  in  on  a  West 
Coast  station  at  the  same  time  as  he  did  on 
an  East  Coast  station,  that  voice  from  the  East 
would  arrive  in  his  ears  one  fifteenth  of  a  se- 
cond later  than  that  from  the  West:  the  voice 


448 


Radio  Broadcast 


LAYING  DOWN  THE  LAW  TO  PROSPECTIVE  AMATEUR  OPERATORS 

When  the  successful  applicant  in  New  York  passes  his  test  for  an  operator's  license,  he  is  given  a  talk  by  J.  W.  Swanson, 
Radio  Inspector,  who  is  seen  at  the  left.  The  incipient  ham  is  asked  not  to  transmit  during  broadcasting  hours,  be  on  the 
alert  for  SOS  signals,  and  generally  maintain  the  best  traditions  of  the  amateur 


from  the  New  York  station  would  sound  like  an 
echo  from  the  San  Francisco  station.  Since  the 
test  was  not  carried  out,  however,  no  one  had  the 
opportunity  of  hearing  such  a  phenomenon. 

The  Telephone  Company's  Part  in  This 
Work 

IT  IS  interesting  to  us  that  our  guess  as  to  the 
reasonable  and  probable  development  in 
radio  broadcasting  is  so  quickly  being  vindi- 
cated. That  the  development  and  execution  of 
this  new  form  of  communication  would  un- 
doubtedly be  carried  out  by  the  great  research 
and  engineering  staffs  of  our  nation-wide  com- 
munication organization — The  American  Tele- 
phone and  Telegraph  Company — seemed  to  us 
the  only  logical  possibility.  This  company  has 
spent  a  tremendous  amount  of  money  in  train- 
ing its  research  staff  and  in  accumulating 
information  essential  in  the  field  of  speech 
transmission.    Any  other  organization  would 


necessarily  have  to  incur  similar  expense  to 
be  on  an  equal  footing  in  the  game,  and  even  if 
this  uneconomical  step  should  be  decided  upon 
it  would  still  be  a  long  way  behind  the  Tele- 
phone Company  in  the  race  for  new  and  better 
accomplishment. 

It  seems  assured  that  radio  broadcasting 
must  necessarily  be  completely  interlinked 
with  the  wire  network  covering  our  country; 
we  cannot  conceive  of  it  growing  independently 
here  and  there  over  the  land,  in  isolated  spots. 
This  is  not  the  way  it  will  really  develop  into 
a  country-wide  service.  No  matter  how  good 
the  isolated  stations  may  be  they  must  still 
play  a  minor  role  in  the  tremendous  field  which 
radio  is  destined  to  fill. 

It  is  a  very  good  thing  for  the  art  that  there 
are  so  many  excellent  stations  operating  in- 
dependently of  the  Telephone  Company;  com- 
petition makes  for  greater  progress  and  stimu- 
lates the  engineers  and  managers  to  produce 
better  and  better  programs,  all  of  which  ben- 


The  March  or  Radio 


449 


efits  the  listening  public.  These  independent 
stations  cannot  perform  the  same  service, 
however,  as  a  network  of  stations,  scattered  all 
over  the  country  and  interconnected  for  opera- 
tion by  the  same  voice.  It  is  this  possibility 
that  gives  to  radio  broadcasting  its  great 
potential  value  and  importance;  the  Chief 
Executive  addressing  the  country  is  no  longer 
a  dream,  it  can  be  accomplished  to-day. 

By  using  part  of  their  transcontinental,  high- 
quality,  telephone  line,  the  telephone  engineers 
were  ready  to  deliver,  the  President's  voice  all 
the  way  across  the  country  with  imperceptible 
distortion.  At  San  Francisco,  Omaha,  Chicago, 
New  York,  and  Round  Hill,  the  modulators  of 
the  radio  stations  were  regulated  to  function  as 
well  as  though  the  speaker  were  personally 
in  the  studio.  Three  thousand  five  hundred 
miles  of  telephone  line  were  to  be  tied  up  in  the 
demonstration,  a  fact  which  shows  at  once  how 
it  is  that  radio  broadcasting  must  become  an 
integral  part  of  the  rest  of  the  country's  com- 
munication scheme. 


Simplified  Receiving  Sets 

DURING  the  past  year,  nearly  every  issue 
of  a  radio  journal  or  newspaper  has 
brought  glad  tidings  of  a  new  and  more 
efficient  receiving  circuit.  We  long  ago  stopped 
trying  to  keep  a  record  of  these  supposedly  novel 
ways  of  using  a  vacuum-tube  detector,  because  it 
seems  that  in  the  end,  after  all  the  required  re- 
finements are  made,  they  amount  to  about  the 
same  thing.  Experts  tell  us  that  it  makes  but 
little  difference  what  circuit  is  used — that  if 
sufficient  skill  and  intelligence  are  displayed  in 
properly  proportioning  the  various  parts,  prac- 
tically the  same  results  can  be  obtained  with  any 
of  the  recommended  circuits.  This  seems  a 
logical  conclusion  to  one  understanding  the 
principle  of  the  vacuum  tube,  yet  many  times  the 
enthusiast  solemnly  declares  one  circuit  is 
incomparably  better  than  the  one  he  has  been 
using  (and  which  he  recommended  to  us  only 
a  few  days  before)  and  which  we  haven't  yet  had 
time  properly  to  try  out.    We  have  one  ac- 


THE  FIRST  THREE  HEROES  TO  RECEIVE  THE  RADIO  MEDAL 
The  award  of  this  medal  is  restricted  to  wireless  operators,  and  the  first  three  were  presented  to  the  three  operators  of  the 
City  of  Honolulu  which  burned  and  sank  in  the  Pacific  last  spring.    Mayor  Cryer  of  Los  Angeles  made  the  presentation 
for  the  Radio  Corporation  of  America.    Left  to  right:  N.  C.  Kumler,  Mayor  Cryer,  Walter  P.  Bell  (Chief  Operator), 

and  H.  D.  Hancock 


45© 


Radio  Broadcast 


quaintance  whom  we  have  dubbed  the  "circuit 
shark."  He  can  draw  out  at  any  time  practically 
any  circuit  which  has  been  shown  to  him;  it 
seems  as  though  his  brain  must  be  filled  with 
short  circuits  with  all  those  connection  schemes 
loaded  one  on  top  of  the  other.  His  last  circuit 
is  always  the  best.  Probably  all  of  you  number 
someone  like  him  among  your  acquaintances. 

However  much  various  circuits  of  the  same 
general  kind  measure  up  to  one  another  as 
regards  their  sensitiveness,  it  is  a  fact  that 
one  particular  circuit  may  be  much  superior  to 
another  in  the  ease  with  which  the  requisite  ad- 
justments can  be  carried  out.  In  this  we  see  a 
great  chance  for  improvement  in  the  future  re- 
ceiver; surely  the  one-dial  receiver  is  bound  to 
come.  The  average  non-technical  man  cannot 
be  expected  to  acquire  the  skill  demanded  by 
the  very  sensitive  sets,  requiring  the  simultane- 
ous adjustment  of  perhaps  four  dials,  condensers, 
coils,  filament  current,  coupling,  regeneration, 
and  what  not.  Many  people  don't  care  for  the 
tinkering  part  of  the  job;  they  want  the  sets  for 


the  programs  they  bring  in.  For  such  listen- 
ers, the  manipulation  of  the  set  should  be  the 
simplest  possible.  The  popular  Westinghouse 
RC  receiver  was  a  good  attempt  to  simplify  the 
adjustments  required  with  a  regenerative  set  but 
this  still  leaves  much  to  be  desired.  It  requires 
considerable  skill  to  get  the  best  results,  and 
furthermore  has  the  bad  feature  of  re-radiation 
from  the  antenna. 

As  we  look  at  the  various  good  sets  available 
to-day  it  seems  that  the  difficulty  of  proper  ad- 
justment is  a  necessary  result  of  trying  to  get  the 
very  best  results  out  of  each  tube  in  the  set — 
naturally  a  very  desirable  condition.  But,  if 
much  can  be  gained  in  simplicity  by  sacrificing 
some  of  the  sensitiveness  of  the  tubes,  it  should 
be  worth  while.  As  the  present  tubes  use  so 
little  power  for  the  filament  and  plate,  the  in- 
crease in  upkeep  of  a  set  having,  say,  two  more 
tubes  than  the  present  sets,  would  not  be  great. 
It  seems  to  us  that  a  set  having  radio-  and  audio- 
frequency amplification,  without  regeneration, 
must  be  possible  in  such  a  design  that  the  only 


.Lit.-..  •»•* 


mmmm  fhu 


■sat  ^  J  /-  'ff\^t'\  %s&29<'  p 


Hi 


RADIO  CONCERTS  IN   PLACE  OF  PUBLIC  BANDS  IN  PARIS 
Here  is  a  crowd  gathered  about  one  of  the  old  band  stands  on  the  Champs 
Elysees,  listening  to  music  from  the  Eiffel  Tower  station  just  across  the  river 


*  at 


1 i§*j#  7^^^%  «M  m. 


The  March  of  Radio 


45' 


THE  PROGRAM  DOESN  T  SEEM  TO  AGREE  WITH  CURLY  HAIR 

All  the  other  "members  of  the  radio  audience,"  however,  seem  gravely  attentive  to  the  out- 
put of  the  receiver  with  which  they  are  being  entertained  in  Central  Park,  New  York 


adjustment  required  is  the  one  dial  tuningthe  an- 
tenna circuit — the  antenna  being  a  loop.  A  good 
loop  antenna  is  sufficiently  selective,  both  because 
of  low  resistance  and  directive  qualities,  to  tune 
out  ordinary  interference,  and  such  an  antenna 
with  three  steps  of  untuned  radio-frequency 
amplification  with  two  steps  of  audio-frequency 
amplification  should  be  sufficiently  sensitive  to 
bring  in  any  station  within  reasonable  distance. 

If  such  a  set  is  not  practicable,  then  a  super- 
heterodyne outfit  should  be  possible  which  with 
about  seven  tubes  would  give  all  the  volume 
and  all  the  selectivity  desired.  Such  a  set  is 
feasible  with  only  one  adjusting  dial,  and  al- 
though the  first  investment  for  tubes  would  be 
high,  it  seems  that  it  would  be  worth  while  for 
the  average  radio  customer  to-day.  To  do  away 
with  the  tinkering — simply  to  turn  one  handle  to 
a  definite,  marked  point  and  get  the  station 
wanted,  if  it  is  transmitting — that  is  the  kind  of 
a  set  which  will  probably  find  a  good  deal  of 
favor  in  the  future. 


The  Size  of  Radio  Audiences 

IN  TWO  circulars  emanating  from  the  news 
bureau  of  the  General  Electric  Company, 
there  is  given  some  interesting  information 
which  illustrates  the  optimism  of  the  broadcast- 
ing station  manager — information  which  en- 
ables us  to  picture  quite  well  the  distribution  of' 
the  radio  audience  of  such  a  powerful  station  as 
WGY,  Schenectady,  N.  Y. 

In  the  first  circular  we  learn  that  WGY  has 
received  in  all  65,000  letters  from  its  enthusiastic 
listeners,  since  the  inauguration  of  broadcasting 
activities  sixteen  months  ago.  These  letters 
come  from  points  as  widely  separated  as  Hawaii 
and  England  and  as  Vancouver  and  Valparaiso. 
With  such  landmarks  to  delineate  his  nightly 
audience,  it  is  no  wonder  the  manager  counts  his 
listeners  by  the  million. 

We  learn  that  "there  are  at  least  2,000,000 
radio  sets  in  the  country  and  of  that  number 
1,500,000  are  almost  nightly  within  range  of 


452 


Radio  Broadcast 


PEOPLE  SIX  MILES  AWAY  OBJECTED  TO  THIS  LOUD  SPEAKER 

Programs  were  sent  out  on  sound  waves  from  this  tower  over  the  whole  countryside  by  Colonel  Edward  H.  R.  Green,  son 
of  the  late  Hetty  Green,  of  South  Dartmouth,  Mass.     Residents  over  in  Nonquitt  were  not  so  keen  as  was  the  Colonel, 
however,  for  this  unusual  volume  of  sound,  and  accordingly  the  concerts  were  discontinued 


WGY."  Even  with  no  further  data  to  estab- 
lish a  judgment,  one  would  be  entitled  to  the 
conclusion  that  in  Schenectady  some  optimism- 
giving  fluid  must  still  be  obtainable;  and  in  the 
other  circular  a  very  interesting  bit  of  infor- 
mation is  contained  in  these  words:  "After  a  re- 
cent minstrel  show  broadcast  by  WGY,  1400 
letters  were  received  by  the  station  within  24 
hours.  Over  2000  letters  were  received  within 
a  week,  referring  to  this  particular  entertain- 
ment." Now  these  two  sentences  furnish  us 
with  apparently  reliable  data  as  to  the  distri- 
bution of  WGY's  audience,  and  incidentally 
that  of  any  similar  station. 

As  no  mail  collections  are  made  late  in  the 
evening  (after  the  radio  concert)  all  of  these  1400 
letters  must  have  started  on  their  way  to  WGY's 
manager  the  next  morning, — and  they  all 
reached  him  that  same  day,  after  a  necessarily 
short  journey  !  It  would  appear  that  they  could 
not  have  travelled  more  than  perhaps  200  miles 
if  they  were  to  be  delivered  in  Schenectady  the 
same  day,  so  it  seems  reasonable  to  believe  that 
70  per  cent,  of  the  audience  of  WGY,  one 


of  our  most  powerful  stations,  is  not  more  than 
about  100  miles  away  from  the  station.  In  view 
of  the  first  statement  quoted,  this  would  lead  one 
to  believe  that  of  the  "2,000,000  sets  in  the 
country,"  1 ,500,000  of  them  are  in  the  vicinity  of 
Schenectady.  We  are  willing  to  admit  the  at- 
tractiveness of  certain  parts  of  this  country 
town,  but  surely  the  radio  station's  manager  is 
over-enthusiastic  about  it  when  he  puts  about 
half  the  country's  radio  listeners  within  a  short 
day's  journey  of  his  city.  Well — such  optim- 
ism is  what  makes  the  news  look  attractive. 

De  Forest  Company  Beaten  by  the 
Westinghouse  Company 

ABOUT  ten  years  ago,  Armstrong  was 
granted  the  patent  on  vacuum-tube 
l  operation  which  was  destined  to  play 
an  important  part  in  the  commercial  develop- 
ment of  radio  in  the  coming  decade.  Many  of 
us  didn't  then  appreciate  the  commerical  possi- 
bility of  the  patent — in  fact  it  would  have 
taken  a  man  with  a  super-imagination  to  pic- 


The  March  of  Radio 


453 


ture,  then,  the  radio  development  which  was  to 
take  place  during  that  span  of  years.  From 
five  thousand  sets  to  five  million-^that  simple 
comparison  gives  very  nearly  the  relative  num- 
bers of  radio  listeners,  and  of  course  also  in- 
dicates the  increase  in  the  value  of  such  a  patent 
as  Armstrong  was  granted.  Roughly  speaking, 
this  fundamental  patent,  which  has  been  in- 
terpreted by  the  Courts  to  cover  any  scheme 
which  makes  possible  the  transfer  of  the  B 
batten'  energy  back  into  the  grid  circuit,  has 
thus  increased  in  value  a  thousand  fold  during 
the  less  than  ten  years  of  its  life. 

In  the  early  days  of  the  patent,  of  course, 
broadcasting  was  unknown  as  we  have  it  to- 
day, and  practically  the  whole  value  of  the 
patent  lay  in  the  possibility  of  selling  regenera- 
tive sets  to  the  radio  amateur;  but  the  radio 
amateur,  it  developed,  isn't  a  very  good  cus- 
tomer for  complete  sets,  because,  after  he  knows 
how,  he  generally  prefers  to  build  his  own. 
Because  of  this  situation  Armstrong  was  not 
then  able  to  realize  much  on  his  idea.  Seven- 
teen companies  did  agree  to  make  regenerative 
sets  under  a  license  granted  them  by  Arm- 
strong for  a  nominal  fee,  his  returns  to  be  had 
from  royalties  on  the  sales  of  the  manufacturing 
companies. 

These  licenses  were  rather  restricted  in  that 
they  limited  the  activities  of  the  manufacturing 


companies  to  making  and  selling  sets  for  ama- 
teurs, experimenters,  and  scientific  schools — 
moreover  the  licenses  were  not  transferable. 
In  those  days,  De  Forest  probably  did  not  ap- 
preciate the  value  and  uniqueness  of  Armstrong's 
patent.  Apparently  he  thought  he  could  do 
as  well  himself  in  the  patent  office,  so  he  did  not 
consider  it  worth  while  to  take  out  a  license. 
His  attitude  is  perfectly  easy  to  understand — 
a  pioneer  of  his  standing,  having  undoubted 
right  to  the  audion  patents,  applying  to  a  young 
student  for  permission  to  use  his  own  device  in 
a  circuit  very  similar  to  that  he  had  always  used, 
and  to  pay  money  to  the  young  student,  who  had 
frequently  publicly  challenged  De  Forest's 
understanding  of  the  action  of  the  audion,  for 
permission  to  put  an  extra  coil  or  condenser  in 
his  circuits — this  must  have  seemed  out  of  the 
question  to  the  inventor  of  the  audion,  and  he 
didn't  do  it. 

As  a  result,  a  few  years  later  he  found  his  com- 
pany rather  embarrassed  in  the  competition  for 
the  radio-receiver  market.  People  wanted  a  re- 
generative set  because  the  technical  press  told 
them  this  was  the  only  reasonable  set  to  pur- 
chase- As  the  patent  had  in  the  meantime  been 
acquired  by  the  Westinghouse  Company  for  a 
goodly  sum,  he  found  that  the  valuation  placed 
on  a  license  had  gone  up  by  leaps  and  bounds  so 
that  it  seemed  now  not  a  question  of  pride,  but 


THE  RADIO  CORPORATION'S  NEW  MESSAGE  CENTRE  AT  64  BROAD  STREET,  NEW  YORK 
In  this  room,  messages  are  exchanged  at  high  speed  between  America  and  France,  Norway,  Germany,  and  Great  Britain 
via  the  great  transmitting  station  at  Rocky  Point,  L.  I.  and  the  receiving  station  at  Riverhead,  L.  I.    The  wavelengths 

used  are  from  10,000  to  20,000  meters 


454 


Radio  Broadcast 


The  Leviathan  Breaks 
Some  Records 


A° 


ANOTHER  RECORD  FOR  THE  LEVIATHAN 

Chief  Radio  Officer  Pickerill  and  his  assistant,  A.  C.  Tamburino,  are  holding  some 
of  the  4000  messages  sent  and  received  during  the  vessel's  first  trip  to  Europe  and 
back  since  her  reconditioning 


CCORDING  to  an  an- 
nouncement of  the 
Western  Electric 
Company,  the  radio  appa- 
ratus installed  on  our  larg- 
est liner  has  set  a  new 
mark  for  merchant-marine 
radio.  The  ship  not  only 
broke  all  previous  communi- 
cation records  by  transmit- 
ting 15,000  words  a  day, 
to  and  from  shore,  but 
managed  to  keep  in  con- 
stant touch  with  land  radio 
stations  from  one  thousand 
to  thirteen  hundred  miles 
away.  By  means  of  new 
apparatus  specially  designed 
for  it,  the  Leviathan  oper- 
ated simultaneously,  for 
long  periods  of  time,  two 


sending 


rather  of  finances,  in  acquiring  a  license. 
Again  he  didn't  do  it.  A  possible  loophole  was, 
however,  still  left  to  him — to  absorb  one  of  the 
small  concerns  which  had  obtained  a  patent 
license  and  thus  market  his  wares  through  a 
properly  licensed  company.  This  was  appar- 
ently done,  and  various  other  methods  of 
making  the  best  of  a  rather  disadvantageous 
situation  were  subsequently  attempted. 

Under  a  decree  recently  issued,  the  U.  S.  Dis- 
trict Court  of  New  Jersey  decided  the  case 
against  the  De  Forest  Company  and  the  Radio 
Craft,  Incorporated  (the  small  company  which, 
although  retaining  its  name,  had  been  essentially 
absorbed  by  the  De  Forest  Company).  The 
verdict  of  the  Court  was  in  favor  of  the  owner 
of  the  patent,  the  Westinghouse  Electric  and 
Manufacturing  Co. 

The  Court's  decision  also  contained  a  warn- 
ing for  those  unlicensed  companies  which  have 
been  putting  out  non-regenerative  receivers 
so  built  that  they  might  readily  be  changed 
into  the  regenerative  type  by  the  addition  of 
a  simple  connection,  or  by  a  similar  subter- 
fuge. This  perfectly  just  and  proper  decision 
of  the  Court  emphasizes  the  advantage  which 
the  Westinghouse  Company  acquired  in  pur- 
chasing patent  No.  1,113,149. 


two  for  sendint 


and  re- 
The  steam- 
ship carries  four  antennas, 
and  two  for  receiving. 


different 
ceiving  sets 


F 


A  Radio  Blind  Spot 

'ROM  far-away  Oregon  comes  an  interest- 
ing letter  telling  of  experiments  being 
carried  out  in  the  mountainous  region  of 
that  state  to  find  out  definitely  some  of  radio's 
reputed  aversion  for  certain  locations.  Station 
KFAY  is  located  in  Medford,  among  the  moun- 
tains of  southwest  Oregon.  Its  signals  are 
heard  as  far  away  as  Montana,  to  reach  which 
they  must  travel  right  across  the  state.  Di- 
rectly in  their  path  is  the  town  of  Prospect, 
only  forty  miles  away  from  Medford — and  yet 
the  station  is  never  heard  in  Prospect.  The 
waves  apparently  jump  right  over  Prospect  in 
their  haste  to  reach  Montana!  Tests  at  points 
around  the  "dead  spot"  seem  to  show  it  to  be 
very  definitely  limited.  At  a  point  twelve  miles 
past  the  dead  zone  the  signals  come  in  strong 
and  clear.  The  question  of  bad  grounds  at 
one  point  and  good  grounds  at  others,  has  been 
taken  up  in  the  experiments. 

We  are  gradually  learning  that  such  things 
really  do  exist,  and  many  of  our  readers 
have  probably  experienced  much  difficulty  in 
getting  certain  stations  while  other  stations, 


The  March  of  Radio 


455 


not  so  powerful,  or  more 
distant,  come  in  with  plenty 
of  volume.  It  is  worth 
while,  therefore,  to  record 
such  a  phenomenon,  when 
it  is  vouched  for  by  the 
careful  experimenters  of 
KFAY,  who  sent  us  the 
account  of  the  tests. 

We  mentioned  quite  some 
time  ago  that  very  careful 
measurements  by  radio  en- 
gineers showed  that  the  rad- 
iation from  WEAFwas  only 
one  twentieth  as  strong  in  a 
certain  direction  as  it  was 
in  others;  that  there  was  a 
kind  of  radio  hole,  actually 
mapped  and  measured 
quantitatively,  for  which 
the  probable  cause  seemed 
to  be  the  absorption  of  the 
signal  by  the  steel  struc- 
tures of  Manhattan.  Of 
course,  no  such  cause  as 
this  can  be  ascribed  to  the 
Medford  station,  as  the  sky- 
scrapers haven't  yet  arrived 
in  that  city.  It  may  be  that 
there  is  a  very  large  ore  body 
around  Medford  playing 
pranks  with  the  waves. 

A  knowledge  of  radio  "blind  spots"  is  well 
worth  gaining;  if  the  region  is  sufficiently  im- 
portant (as  it  is  in  the  case  of  WEAF)  a 
small  station  could  be  located  near  the  dead 
region  and  operated  from  the  main  station  by 
land  wires,  thus  giving  local  radiation  to  "fill 
up  the  hole." 

Incidentally,  the  map  of  the  country  sur- 
rounding the  station  at  Medford  (sent  to  show 
the  kind  of  country  in  which  the  effect  oc- 
curred) is  incorporated  in  a  circular  setting 
forth  the  attractions  of  southeast  Oregon. 
Looking  the  circular  over  made  us  quite  forget 
the  trouble  with  radio  waves,  and  regret  that 
our  vacation  trip  was  already  over.  If  these 
words  happen  to  come  to  the  attention  of  the 
Chamber  of  Commerce  of  Medford,  they  may 
feel  assured  of  having  procured  at  least  one 
visitor  in  the  near  future,  because,  if  they 
really  have  such  fishing  as  the  circular  boasts, 
we  shall  probably  bring  our  camping  outfit 
along  and  stay  in  that  exceedingly  attractive 
region  for  quite  some  time. 


CORNELIUS  COLE,    101,  AND  RiCHARD  HEADR1CK,  6,  AT  KHj 

A  Man  Who  Knew  Lincoln 

PRECEDING  the  hordes  of  strong  men 
who  swept  across  the  western  plains  in 
the  gold  rush  of  '49  came  Cornelius 
Cole.  He  found  something  more  precious 
than  gold  in  California — the  joy  of  service  to 
this  country  and  to  humanity. 

The  aged  statesman  and  centenarian — 
he  celebrates  his  101st  birthday  in  September — 
was  a  United  States  senator  and  a  confrere  of 
Abraham  Lincoln  in  the  dismal  days  of  the 
Civil  War.  He  was  born  on  September  17,  1822, 
during  the  administration  of  President  Monroe. 

On  July  3rd  last,  he  sat  in  the  studio  of  the 
Los  Angeles  Times'  radio  station,  with  little 
Richard  Headrick,  film  actor  and  violin 
prodigy,  6  years  of  age,  on  his  knee,  and  gave  a 
graphic  recital  of  his  personal  recollections  of 
Lincoln.  His  words  from  a  Los  Angeles  radio 
station,  personally  commemorative  of  President 
Lincoln,  and  his  description  of  the  law  abolish- 
ing slavery,  in  which  he  took  an  active  part, 


456 


Radio  Broadcast 


Underwood  &  Underwood 

IN  THE  CRYSTAL  STUDIO  AT  WJAZ 

Guests  at  the  Edgewater  Beach  Hotel,  Chicago,  can  see  the  performers  in  the  broad- 
casting studio  through  plate  glass  windows  which  are  three-ply  and  hence  abso- 
lutely sound-proof.    The  microphone  is  concealed  under  the  lamp  at  the  left  of  the 

picture 


were  a  privilege  which  probably  will  never 
again  be  had.  July  3rd  was  an  anniversary  of 
the  Battle  of  Gettysburg  and  Mr.  Cole  told  the 
radio  listeners  of  his  feelings  as  he  sat  on  the 
platform  a  few  feet  from  the  Great  Emanci- 
pator while  the  latter  was  sounding  the  phrases 
of  his  immortal  Gettysburg  address. 

The  sight  of  the  venerable  pioneer  with  the 
youthful  "star"  on  his  knee  was  something 
never  to  be  forgotten  by  the  guests  in  the  studio. 

New  Super-Cable 

SOME  time  ago  we  quoted  one  of  the  tele- 
graph executives  as  prophesying  that  the 
'  ocean  cable  was  soon  to  have  certain  im- 
provements which  would  discount  the  rapid 
strides  transoceanic  radio  has  been  making. 
Although  minor  improvements  are  continually 


being  made  in  the  receiving 
apparatus  used  with  the 
ocean  cable,  little  real  prog- 
ress has  been  made  since 
radio  started  on  its  phe- 
nomenal advance.  Contrary 
to  what  many  people  think, 
electric  currents  do  not  al- 
ways travel  with  the  speed  of 
light;  especially  is  this  true 
with  the  currents  passing 
over  the  ocean's  bottom 
through  the  gutta-percha- 
covered  cables  guiding  them 
across.  An  appreciable  frac- 
tion of  a  second  elapses  after 
the  switch  is  closed  in  Eu- 
rope, before  the  sensitive  re- 
ceiving galvanometer  records 
the  arrival  of  any  current  in 
America.  Owing  to  the  ab- 
sorption of  the  electric 
charge  by  the  rubber  insula- 
tion, and  a  lack  of  an  appre- 
ciable magnetic  field  around 
the  cable,  the  maximum 
available  speed  of  transmis- 
sion is  a  comparatively  few 
words  a  minute.  The  rubber 
insulation  used  has  much  to 
do  with  this  slowness  of 
travel,  but  this  rubber  is  re- 
quired to  maintain  the  high 
insulation,  otherwise  the 
comparatively  weak  currents 
would  all  leak  out  into  the 
ocean  before  going  far  in  the  cable.  If  a 
stronger  magnetic  field  could  be  set  up  around 
the  cable,  when  it  is  carrying  its  signaling  cur- 
rent, the  speed  of  signaling  might  be  consider- 
ably increased. 

According  to  an  announcement  of  Mr.  Carl- 
ton, of  the  Western  Union  Telegraph  Company, 
such  a  scheme  is  now  available  and  is  being  in- 
stalled by  his  company,  in  a  cable  which  is  to 
reach  from  the  United  States  to  Italy.  The 
engineers  of  the  Western  Electric  Company's  re- 
search laboratories  have  discovered  a  new  alloy 
which  has  such  magnetic  properties  that  a  thin 
layer  of  it  wound  over  the  rubber  insulation  will 
increase  the  magnetic  field  around  the  cable 
many  times,  and  thus  make  possible  quicker 
signal  transmission.  Such  a  cable  was  sug- 
gested many  years  ago  by  a  Danish  engineer, 
Krarup,  but  the  proper  kind  of  iron  was  not  then 


The  March  of  Radio 


457 


available  to  make  his  idea 
feasible.  The  speed  of  signal- 
ing with  this  new  cable  will, 
according  to  Mr.  Carlton,  be 
several  times  as  great  as 
with  the  older  type  of  cable. 

Is  Wired  Wireless  the 
Future  of  Broadcasting? 

E  HEAR  from 
time  to  time 
about  the  experi- 
ments being  carried  on  to 
show  the  feasibility  of  using 
high-frequency  currents, 
sent  over  wires,  to  displace 
the  present  broadcasting 
scheme,  in  which  radiated,  as 
contrasted  with  guided,  high- 
frequency  power  is  used. 
This  idea  is  generally  cred- 
ited to  Maj  or-General 
Squier,  Chief  Signal  Officer 
of  the  U.  S.  Army,  who  car- 
ried on  extensive  experi- 
ments with  "wired  wireless" 
in  Washington,  D.  C. 

The  attractive  feature 
about  this  method  of  fur- 
nishing service  is  the  ease 
with  which  revenue  could  be 
equitably  collected  for  fi- 
nancing the  scheme.  The 
subscriber  could  pay  for  the 
evening's  entertainment  just  as  he  now  pays  for 
the  ordinary  telephone  service.  Furthermore, 
there  should  be  less  interference  with  such  a 
scheme  than  there  is  with  the  present  broadcast- 
ing scheme.  Certainly,  such  channels  of  com- 
munication as  do  require  radio  (ship-to-ship  and 
ship-to-shore  traffic),  would  have  available  more 
frequencies  than  they  now  have. 

It  is  true  that  there  is  a  tremendous  plant  in 
the  form  of  telephone  installations  which  work 
but  a  very  small  part  of  the  time,  so  that  any 
other  service  which  can  be  furnished  over  the 
present  wire  system  would  be  economically 
desirable — provided  of  course  that  it  did  not  in- 
terfere with  the  present  necessary  service. 

Granted  however  that  carrier-current  instal- 
lation does  offer  possibilities  for  a  new  service 
over  the  wires — and  the  account,  in  this  issue 
of  Radio  Broadcast,  of  the  wired  Radio  Service 
Company's  successful  experiments  on  Staten 


THE  NEW  STAND  BUILT  FOR  THE  N.  Y.  PHILHARMONIC  ORCHESTRA 

Willem  Von  Hoogstratem  is  shown  conducting  his  orchestra  of  106  men,  at  one  of 
the  Stadium  concerts  in  New  York.  The  stand,  erected  by  the  General  Electric 
Company,  is  portable  and  adapted  especially  for  the  broadcasting  of  the  orchestra's 
programs.  The  two  black  dots,  one  above  the  other,  to  the  right  of  the  leftrhand 
pillar,  are  the  microphones 


Island  seems  to  support  this  premise — it  will 
be  an  addition  to  radio  broadcasting,  instead 
of  a  substitute  for  it.  We  have  the  strong- 
est kind  of  conviction  that  radio  has  become  a 
permanent  part  of  our  day's  activities  and  that 
in  the  future  it  will  be  even  more  necessary 
to  us  than  at  present.  Radio  broadcasting 
reaches  many  places  where  there  are  no 
wires  and  probably  always  will  do  so.  The  real 
service  that  broadcasting  can  furnish  is  a  demon- 
strated fact,  and  the  other  service  still  needs  to 
be  proved.  For  many  of  us,  "tuning-in"  on 
various  stations  has  a  fascination  which  "wired 
wireless"  would  lack  entirely.  It  seems  prob- 
able that  in  the  larger  cities,  where  the  telephone 
system  may  be  suitably  adapted  to  give  carrier- 
current  entertainment  without  unreasonable 
expense,  it  will  be  done,  so  that  subscribers  may 
either  tap  the  wires  or  tap  the  ether  for  their 
evening's  entertainment.  J.  H.  M. 


"  roxie" 

S.  L.  Rothafel,  whose  informal  and  witty  announcements  during  the  concerts  broadcasted  by  his  Capital  Theatre  Orchestra 
and  "Gang"  have  made  him  very  popular  among  the  radio  audience.    He  tells  of  his  past  history — from  $2-a-week  days 
and  failure  in  book-agenting  to  struggles  with  a  country  moving-picture  theatre  and  final  success  in  New  York 


_ 


THE  "GANG"  AND  "ROXIE" 
Top  Row:  Left  to  Right:  William  Axt  ("Dr.  Billy"),  Carl  Scheutze.  Helena  Marsh,  Yascha  Bunchuk,  Frederick  Jagel 
Middle  Row:  Eugen  Ormandy  ("The  Blue  Blond"),  Melanie  Dowd,  Louise  Scheerer,  Mme.  Elsa  Stralia,  Editha 

Fleischer,  Bruce  Benjamin 

Lower  Row:  Edna  Baldwick,  Nadia  Reisenberg,  S.  L.  Rothafel  ("Roxie"),  "Betsy"  Ayres,  Evelyn  Herbert 


A  Bit  About  Myself 

The  Story  of  the  Early  Struggles,  Varied  Experiences,  and  Final  Success 
of  a  Man  Who  is  Well  Known  to  Thousands  Who  Listen  to  the  Capitol 
Theatre  Concerts  Broadcasted  Through  WEAF,  WCAP  and  W  M  A  F 

By  "ROXIE"  (S.  L.  ROTHAFEL) 

Presentation  Director,  Capitol  Theatre,  New  York 


IN  THIS  helter-skelter  life  in  which  we  find 
ourselves,  our  minds  are  likely  to  focus  al- 
most exclusively  on  the  situation  of  the 
moment;  we  are  wont  to  forget,  in  follow- 
ing the  pace  of  the  present  and  preparing 
for  the  immediate  future,  the  varied  joys  of 
yesterday.  As  a  rule,  the  bygone  years,  in 
retrospect,  are  shaded  to  a  great  degree  by  the 
incomparable  brush  of  Father  Time  in  a  man- 
ner that  blends  sadness  and  happiness  into  a 
picture  of  subdued  color  and  great  beauty. 
The  business  of  to-day  renders  the  thoughts  of 
yesterday  a  pleasure  that  most  of  us  can — or 
at  least,  do — find  little  time  for,  despite  the 
many  blessings  which  a  bountiful  passing  of 
years  has  showered  upon  us. 

My  friends — and  1  feel  justified  in  believing 
that  most  of  you  who  read  these  few  words 


are  my  friends — the  preparation  of  this  sketch 
makes  it  possible  for  me  to  look  over  the  de- 
parted years  as  they  pass  in  review  and  are  re- 
corded here  at  my  pen-point.  This  form  of  in- 
door sport  is  rarely  my  lot,  and  before  I  began 
it  struck  me  as  just  another  obstacle  to  over- 
come; but  as  the  words  form  beneath  my  hand 
the  pleasure  of  the  writing  increases.  I  trust 
that  you,  too,  will  find  it  increasingly  interest- 
ing. 

It  is  quite  unlikely  that  any  day  in  my  life 
was  or  will  be  as  important  as  July  9,  1882 — 
that  was  my  birthday  and  necessarily  marks  the 
beginning  of  my  career  (18  years  to  1900, 
plus  23 — total  41.  Right')-  Whether  I  was 
a  good  baby  or  not  is  a  subject  for  discussion, 
for  I  have  heard  varying  reports  and  must 
admit  that  my  memory  is  not  keen  enough  for 


460 


Radio  Broadcast 


then  in  business  on  14th  Street,  that  I  would 
be  a  valuable  asset  to  his  business  as  a  cash  boy. 
Perhaps  he  was  impressed  by  my  earnestness, 


the  grand  and 
After  the  first 


for  he  agreed  to  hire  me  at 
glorious  salary  of  $2  a  week, 
week,  however,  he  showed  signs  of  impatience. 
The  end  of  the  second  week  found  me  with  my 
second  $2  but  without  a  job. 

DREAMING  AND  SELLING  BOOKS 

DURING  the  next  year  or  so  I  landed,  and 
lost,  one  job  after  another.  I  cannot  blame 
those  good  but  gossiping  persons  who  came  to 
regard  me  as  the  family  black  sheep  and  ne'er- 
do-well.    Yes,  1  was  shiftless  and  a  dreamer, 


WILLIAM  AXT 

Known  to  those  who  have 
heard  "Roxie"  introduce 
him,  as  "  Dr.  Billy" 

me  to  vouch  for  the 
authenticity  of  any  of 
them.  My  birthplace 
was  Stillwater,  Minne- 
sota, a  hamlet  made  fa- 
mous in  song  and  story 
by  some  sage  who  at- 
tributed to  it  the  qual- 
ity of  running  deep. 

As  a  youngster,  1  was 
like  most  others  of  the 
day  and  of  the  environs 
of  Stillwater — given  to 
a  certain  amount  of 
mischief.  An  occasional 
broken  window  as  the 

result  of  an  improperly  aimed  bit  of  snowball 
or  the  report  of  a  bit  of  sharp-pointed  hard- 
ware having  been  placed  upon  someone's  chair 
was  always  sure  to  bring  down  the  paternal  ire 
upon  my  head. 

After  spending  thirteen  years  in  Stillwater, 
my  family  moved  to  New  York.  We  were 
folks  of  less  than  moderate  means,  and  the  cost 
of  our  journey,  coupled  with  my  being  rather 
well  set  up  for  my  years  and  having  a  healthy 
desire  to  put  my  energies  to  work,  culminated 
in  my  looking  for  a  job.  After  quite  a  search  I 
was  able  to  persuade  John  B.  Collins,  who  was 


THREE  CAP1TOL- 

AND  THREE- 

They  have  contributed- 
evening  concerts  given- 
transmitted,  through- 
enthusiastic   and  in  — 


EDNA  BALDWICK 

This  young  pianist  is 
a  popular  member  of 
the  popular  "Gang" 


ERNESTO  LECUONA 

He  is  a  Cuban  pianist,  and 
has  been  playing  some  of  his 
own  compositions  at  the 
recent  Sunday  night  concerts 


A  Bit  About  Myself 


461 


but  in  all  my  shiftlessness  I  was  building  up, 
entirely  unknown  to  myself,  a  symposium  of 
impressions  which  has  followed  me  though  the 
years  and  left  with  me  a  keener,  deeper  and 
more  appreciative  picture  of  human  frailties  and 
kindnesses.  I  have  been  in  intimate  contact 
with  some  pretty  rough  characters,  but  have  yet 
to  find  the  one  in  whose  soul  there  is  no  flame  of 
decency  or  humanity  or  even  a  hidden  love, 
despite  an  exterior  that  would  indicate  none  of 
these  attributes.  There  is,  I  believe,  a  way  to 
the  heart  of  every  one  of  us — and  when  the 
way  is  found,  true  friendship  follows. 

But  that  is  somewhat  aside  from  my  past, 
though  it  may  serve  to  reveal  a  part  of  the 


—PIANISTS 

-CAPITOL  VOICES 

— greatly  to  the  Sunday 
— at  the  theatre  and 
— Station  WEAF,  to  an 
— creasing  radio  audience 


Underwood  &  Underwood 
MME.   ELSA  STRALIA 

From  the  Royal  Opera,  Co- 
vent  Garden,  London.  She 
possesses  a  dramatic  soprano 
voice  and  has  had  great 
success  in  opera  and  concert 
abroad  for  a  number  of  years. 
She  is  a  native  of  Australia, 
and  came  to  America  in  1922 


WILLIAM  ROBYN 

Alias  "  Billy."  His  lyric  tenor 
voice  is  heard  from  time  to 
time  at  the  Capitol.  He  has 
also  made  Victor  records  and 
now  has  a  long-term  con- 
tract with  the  Cameo  Phono- 
graph Company 


LOUISE  SCHEERER 

This  contralto  has  long  been  a 
member  of  the  "Gang,"  and 
sings    in   the  Capitol  quartet 


mental  processes,  born  years  ago,  which  re- 
mained unshaken  as  the  days  rolled  by. 

When  I  was  still  in  my  teens,  I  became  a 
book-agent  and  made  myself  a  most  unwelcome 
visitor  at  many  homes.  1  believed  in  the  books 
I  was  offering  for  sale,  felt  sure  they  would 
bring  pleasure  and  profit  to  those  who  would 
read  them;  but  the  reception  extended  me,  as 
soon  as  the  object  of  my  mission  was  made 
known,  was  a  most  frosty  negation.  This  kind 
of  thing  discouraged  me  greatly.  1  found  it 
difficult  to  reconcile  my  ideas  of  what  life 
should  be,  with  life  as  I  found  it. 

Like  many  another  discouraged  youth  who 
finds  it  hard  to  make  an  honest  living  and  has 


462 


Radio  Broadcast 


(left)  the  "  blue 
blond" 

Otherwise  known  as  Dr.  Eugen 
Ormandy,  concert  master  and  so- 
loist at  the  Capitol  Theatre 


(RIGHT)    ERNO  RAPEE 

Whose  dynamic  baton  has  con- 
ducted the  various  programs  at 
the  Capitol.  Born  in  Budapest, 
he  enjoys  the  reputation  of  being 
a  brilliant  pianist  and  a  composer 
of  no  small  talent.  He  has  con- 
ducted symphonic  concerts  and 
opera  throughout  the  principal 
cities  of  Central  Europe 


no  particular  trade  or  talent  to  fall  back  on,  I 
joined  the  Marines.  The  years  of  my  enlist- 
ment were  among  the  best  years  of  my  life.  I 
met  other  young  men  from  every  walk  of  life 
and  profited  by  my  contact  with  them.  My 
duties  took  me  to  all  parts  of  the  world  and  my 
vision  was  broadened  as  only  travel  can 
broaden  one.  The  discipline,  exercise  and 
training  were  entirely  different  from  anything 
I  had  previously  experienced.  It  quickened 
my  actions,  sharpened  my  wits,  and  provided 
me  with  a  feeling  of  independence  and  self- 
confidence  1  had  not  known  before. 

Fortified  by  this  training,  I  undertook  again 
what  1  had  found  to  be  my  hardest  job:  I  be- 
came a  comparatively  successful  book-agent. 
My  book  peddling  carried  me  into  the  coal 
fields  of  Pennsylvania,  and  it  was  in  Pennsyl- 
vania that  I  met  my  wife-to-be.  We  soon  found 
that  the  old  saying  that  two  could  liveascheaply 
as  one  was  never  set  to  music  by  a  married  per- 
son. Our  entrance  into  matrimony  cut  a  rather 
large  slice  in  the  family  fortune  and  we  held  a 
council  of  war  on  the  two  subjects  of  Finance 
and  Future. 

The  findings  of  the  council  were  that  we 
should  go  into  the  motion-picture  business  im- 
mediately. So  we  did.  That  was  about 
fifteen  years  ago.  In  a  small  town  in  Pennsyl- 
vania we  were  able  to  locate  room  enough  to 
accommodate  a  fair-sized  audience,  behind  a 
bar-room.  The  hall,  as  it  was  called,  was  used 
for  meeting  purposes  and  it  was  supplied  with 
camp  chairs  by  the  local  undertaker.  Inas- 
much as  the  same  chairs  were  used  for  meetings, 
funerals  and  our  movie  enterprise,  our  per- 


formances were  more  or  less  movable  feasts, 
sandwiched  in  between  the  other  uses  for  the 
camp  chairs. 

This  family  "theatre"  of  ours  called  for  a 
great  deal  of  work  and  though  my  wife  had  all 
the  duties  of  our  small  home  to  bother  her,  she 
still  found  time  to  assist  and  encourage  me 
when  the  burden  at  the  show-house  was  par- 
ticularly heavy.  1  did  the  janitor  work, 
painted  the  signs,  secured  the  meagre  publicity 
available,  and  attended  to  the  thousand  and  one 
details  of  the  small-town  theatre. 

After  the  evening  performance,  when  the 
audience  had  left  and  the  house  had  again  been 
put  in  order,  I  used  to  experiment  with  the 
projector  in  an  effort  to  improve  the  quality  of 
our  pictures.  Then,  too,  there  was  the  presen- 
tation to  be  worked  out,  for,  even  in  those 
days,  1  realized  that  the  form  of  presentation  was 
to  play  a  great  role  in  the  success  or  failure  of 
the  silent  drama.  In  order  to  save  enough  to 
pay  the  musicians  and  others  it  was  necessary 
for  me  to  run  my  own  machine.  But  the  re- 
turn for  all  this  effort  was  not  great,  and  showed 
me  that  the  field  was  not  large  enough. 

I  went  to  Philadelphia  after  a  job  and  was 
taken  up  by  the  Keiths.  During  my  stay 
there,  I  originated  and  developed  what  has 
come  to  be  called  twilight  projection,  which  is 
a  system  of  subdued  lighting  making  it  possible 
to  do  away  with  the  dark  theatre. 

A  MEETING  WITH  SARAH  BERNHARDT 

LATER,  when  1  was  working  in  Milwaukee,  it 
,  was  my  good  fortune  to  meet  Sarah  Bern- 
hardt whose  screen  version  of  "Queen  Eliza- 


A  Bit  About  Myself 


463 


beth"  we  were  showing.  She  encouraged  me 
greatly  by  commenting  favorably  upon  the 
presentation  of  her  picture  and  predicting  a 
great  future  for  me.  This  marked  the  turning 
point  in  my  career,  for  this  picture  and  its 
presentation  secured  national  recognition  for 
me. 

Then  I  came  to  New  York  and  opened  at  the 
Regent  Theatre  where  1  employed  my  own  type 
of  presentation  which  proved  to  be  a  sensation. 
Then  1  opened  the  Strand  on  Broadway  and 
later  built  the  Rialto  and  the  Rivoli.  At  present 
I  am  finding  the  business  of  arranging  the  pro- 
ductions at  the  world's  largest  theatre  the  most 
difficult  and  absorbingly  interesting  job  1  have 
yet  experienced. 

As  many  of  you  know,  last  fall  the  American 
Telephone  and  Telegraph  Company  conducted 
a  series  of  experiments  at  the  Capitol  Theatre 
which  resulted  in  the  broadcasting  on  a  particu- 
lar Sunday  evening  of  our  musical  program. 
Reports  from  radio  listeners-in  came  from 
Chicago,  Canada,  Cuba,  Georgia,  Kentucky 
and  vessels  at  sea.  All  the  reports  contained 
enthusiastic  approval  and  the  experiment  was 
repeated  with  such  tremendous  success  that 
weekly  concerts  from  the  Capitol  Theatre  have 
now  become  a  regular  feature  of  the  programs 
from  WEAF. 


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AN   INTERESTING  LETTER  SENT  TO  ROXIE 

This  is  one  of  the  many  thousands  that  have  poured 
into  his  office  since  the  Capitol  first  went  on  the  air 


ROXIE      OFF  DUTY 
He  is  an  enthusiastic  handball  player.    Recently  he  won 
the  Handball  Tournament  at  Rolley's  Gymnasium,  New 
York,  where  this  picture  was  taken 

The  idea  occurred  to  me  as  these  broadcasts 
went  on,  that  here  was  an  ideal  medium  for  us 
to  use  in  making  friends  for  the  Capitol  by 
sending  the  most  beautiful  of  songs  and  music 
into  the  homes  of  the  unseen  audience.  We 
were  inspired  by  the  thought  that  we  could 
make  life  more  livable  and  bright  for  those 
shut-ins  who  for  one  reason  or  another  could 
not  leave  their  homes,  who,  in  a  word,  are  de- 
prived of  those  pleasures  which  we  so  freely 
enjoy  and  frequently  fail  to  appreciate. 

BROADCASTING  WITH  THE  "GANG" 

THE  result  was  that  we  had  a  special  studio 
arranged  and  each  Sunday  evening  my 
"Gang" — composed  of  the  artists  who  entertain 
in  the  theatre — and  I  have  an  hour  before  the 
microphone,  poking  fun  at  each  other  and  at 
you,  and  sending  upon  the  waves  of  ether  the 
world's  best  music.  It  is  one  hour  of  the  week 
to  which  we  all  look  forward  with  pleasure,  for 
during  this  hour  we  meet  many  friends  who 
write  us,  approving  our  efforts  and  thanking 
us  for  the  entertainment  we  give  them. 

We  have  been  fortunate  in  being  able  to  get 
personality  into  the  microphone,  and  I  believe 
that  our  departure  from  the  regular  method  of 


464 


Radio  Broadcast 


ON  AN  EVENING  WHEN  THEY  PLAYED      OVER  THE  RADIO 
Left  to  right:  Eugen  Ormandy  ("The  Blue  Blonde"),  Yascha  Bunchuk  (a  Russian,  " Sheik  of  the  Capitol"),  Bruce 
Benjamin  (tenor),  William  Axt  ("Dr.  Billy" — pianist),  Louize  Scheerer  (contralto).  Evelyn  Herbert  (soprano),  Dorma 
Lee  (in  rear — contralto),  "Roxie"  himself,  Edna  Baldwick  (pianist),  and  "Betsy"  Ayres  (soprano) 


broadcasting  has  made  listening-in  more  pleas- 
ant. Indeed,  I  have  received  some  very  com- 
plimentary letters,  which  indicate  quite  clearly 
that  we  of  the  Capitol  have  been  responsible 
for  the  installation  of  receiving  sets  in  many 
homes  where  they  had  not  been  considered  pre- 
viously.   And  1  must  say  that  my  many  years 


of  showmanship  have  only  made  me  keener  to 
produce  entertainment  of  a  nature  that  makes 
the  audience  feel  thankful  that  they  are  alive 
and  in  a  world  where,  despite  the  cynics,  there 
is  plenty  of  happiness  for  those  who  will  make 
even  a  slight  effort  to  brighten  the  lives  of  their 
fellows . 


Giving  the  Public  a  Light-Socket 
Broadcasting  Service 

How  "Wired  Radio,"  Invented  by  General  Squier,  is  Being  Employed  to  Supply  News, 
Entertainment,  and  Instruction  to  Staten  Island  Subscribers  at  So-Much-a-Month.  Economy 
and  Reliability  are  the  Chief  Assets  of  the  System  Which  may  be  in  Use  Everywhere  Soon 


By  WILLIAM  HARRIS,  Jr. 


UPPOSE  you  had  a  compact  little  sin-       Of  course  the  old- 
gle-control  receiving  instrument  which    casting  (about  two 
you  plugged  into  any  one  of 


s 

f  your  electric  light  sockets 
^ — *^  and  received,  at  specified 
times,  the  latest  world  and  local 
news,  music  of  all  kinds,  play-by-play 
(or  blow-by-blow)  reports  of  the  big 
sporting  events,  extension  courses  in 
whatever  might  interest  you,  infor- 
mation regarding  where  to  shop  for 
everything  from  footwear  to  furni- 
ture, authoritative  talks  on  the  thea- 
tre, books,  health,  cooking,  etiquette, 
and  what-not — all  with  a  minimum  of 
interference,  three  hundred  and  sixty- 
five  days  in  the  year. 

And  suppose  you 
could  get  all  this  at 
about  half  the  cost  and 
none  of  the  bother  or 
uncertainty  of  the  com- 
mon broadcast  receiver. 

You  can — if  you  hap- 
pen to  live  on  Staten 
Island! 

But  if  you  don't, 
nevermind;  because  the 
first  commercially  prac- 
ticable "wired  •  radio" 
broadcasting  service, 
which  has  just  been  put 
into  operation  by  the 
Wired  Radio  Service 
Company,  gives  promise 
of  such  universal  popu- 
larity that  similar  ser- 
vices will  no  doubt 
spring  up  throughout 
the  land  almost  before 
you  have  time  to  read 
up  about  it. 


THE   SET  USED  MOST  FOR  WIRED  RADIO 
RECEPTION 

The  single  tuning  control  is  the  outstanding  feature  of 
this  two-tube  receiver.  A  semi-permanent  crystal  may 
be  clipped  in  place  instead  of  trie  one  shown.  No  A 
batteries  are  required  as  the  lighting  circuit  supplies 
the  filament  current.  To  put  the  set  in  operation,  the 
light  switch  is  turned  on;  when  the  subscriber  is  through 
with  the  set,  he  simply  turns  off  the  light  switch 


fashioned  kind  of  broad- 
years  old  now,  isn't  it?) 
will  not  immediately 
curl  up  its  aerials  and 
die,  leaving  a  vast  and 
sentimental  radio  au- 
dience weeping  over  the 
expensive  carcass.  No, 
the  two  services  will 
continue  side  by  side. 
You  can  probably  think 
of  various  reasons  why 
this  will  be  so.  Here 
are  a  few: 

1 .  Fans  will  always 
want  to  tune-in  "dis- 
tance," both  because  it's 
distance  and  because  ar- 
riving at  success  as  a  re- 
sult of  their  own  skill  will 
never  fail  to  give  a  very 
real  pleasure. 

2.  The  appeal  of  wired 
wireless  is  not  primarily 
to  the  amateurs  and  fans 
— it  is  to  that  far  greater 
part  of  the  population 
which  either  does  not  own 
receiving  sets  or  is  temper- 
amentally disinclined  to 
fuss  with  them. 

3.  "Space"  broadcast- 
ing will  always  be  the  more 
economical  system  in 
sparsely  settled  regions. 
The  wired  wireless  service 
is  essentially  for  towns  and 
cities,  where  the  expense 
per  subscriber  is  low. 

In  brief,  this  is  the 
way  the  Staten  Island 
service  came  into  being: 
The   North  American 


4C.6 


Radio  Broadcast 


TRYING  THE  LOUD-SPEAKER  SET  IN  THE  ROOM  ADJOINING  THE  STUDIO 

From  left  to  right:   J.  Arch  Mears,  President  of  the  Wired  Radio  Service  Company;  E.  W.  Danals,  who  has  aided  in 
the  development  of  the  one-  and  two-tube  wired  radio  sets;  Samuel  Isler;  and  R.  D.  Duncan,  Jr.,  Chief  Radio  Engineer 
of  The  North  American  Company  who  formerly  worked  with  General  Squier  at  Washington  and  has  been  in  charge, 
during  the  past  year,  of  the  experimental  work  of  the  Wired  Radio  Service  Company 


Company,  a  public  utility  holding  company 
operating  electric  lighting  and  power  com- 
panies in  Cleveland,  St.  Louis,  and  many 
other  places,  obtained  a  sixty-day  option  from 
General  Squier  on  a  license  to  use  his  invention 
commercially.  Experiments  in  Cleveland  dur- 
ing this  sixty-day  period  gave  the  officials  of  the 
company  confidence  in  the  tremendous  possi- 
bilities of  wired  wireless  if  properly  applied  for 
public  service.  The  license  was  obtained 
forthwith,  and  further  experiments  over  the 
circuits  of  the  Potomac  Electric  Company  in 
Washington  were  eminently  successful. 

The  rehearsals  having  been  given,  so  to 
speak,  the  show  was  presented  to  the  public — 
on  Staten  Island.  Mr.  C.  W.  Hough,  Presi- 
dent of  Wired  Radio,  Incorporated,  which  is 
controlled  by  the  North  American  Company, 
is  in  general  charge  of  all  this  wired  radio 
work;  and  the  Wired  Radio  Service  Company, 
mentioned  above,  is  a  subsidiary  of  Wired 
Radio,  Inc.,  formed  to  carry  on  operations 
throughout  New  Jersey  and  in  parts  of  New 


York  and  Connecticut.  It  is  this  latter  organ- 
ization which  has  just  started  supplying  a 
daily  broadcasting  service  to  Staten  Island 
homes  over  the  ordinary,  unchanged  house 
lighting  wires. 

Mr.  J.  Arch  Mears,  President  of  the  Wired 
Radio  Service  Company,  says: 

There  are  about  25,000  potential  subscribers  to 
the  service  which  we  have  established  on  Staten 
Island;  but  they  are  only  a  fraction  of  the  number 
which  our  company  expects  to  be  supplying  before 
long.  When  you  consider  that  there  are  in  the 
country  12,000,000  houses  wired  for  electrical  power, 
of  which  the  organizations  associated  with  the 
North  American  Company  supply  approximately 
1,500,000  with  electric  service,  you  can  see  that  if 
even  a  comparatively  low  percentage  of  these 
subscribed  to  the  broadcasting  service,  the  revenue 
from  the  tremendous  business  that  would  result 
would  be  sufficient  to  enable  us  to  procure  the  very 
best  talent,  the  most  important  and  interesting  pro- 
grams. There  are  between  3,000,000  and  4,000,000 
potential  subscribers  (families  or  organizations) 
within  200  miles  of  New  York  City,  the  greatest 


Giving  the  Public  a  Light-Socket  Broadcasting  Service 


467 


THE  SET  USED  IN  RE- 
BROADCASTING 

Music,  speeches,  sporting  events,  etc., 
are  from  time  to  time  tuned  in  with 
this  5-tube  receiver,  put  through  the 
power  amplifier  seen  at  the  right  and 
re-broadcasted  to  the  Company's 
subscribers 


program  source  in  the  world.  The  probable — in 
fact,  the  inevitable — growth  of  wired  radio  which  we 
are  going  to  see  within  a  few  years  fairly  staggers  the 
imagination. 

WHAT  IS  HAPPENING  OVER  ON  STATEN  ISLAND 

BUT  let  us  cross  over  to  the  broadcasting 
plant  on  Staten  Island  and  see  what  is 
going  on  there.  It  is  a  half-hour  ferry  trip 
from  the  Battery  to  St.  George,  then  a 
couple  of  miles'  train  ride  to  West  Brighton, 
where  the  studio  is  located.  The  broadcasting 
is  done  from  a  three-story  stucco  house  leased 
by  the  company.  On  the  first  floor  are  the 
reception  room  and  studio,  the  latter,  like  the 
ordinary  radio  studio,  being  hung  with  heavy 
monk's  cloth  to  absorb  all  sounds  except  those 
entering  the  microphone. 

On  the  second  floor  is  the  transmitter  room, 
containing  the  apparatus  which  delivers  the 
radio-frequency  impulses  directly  to  the  2,300- 
volt  power  lines.  There  are  two  transmitters: 
the  small  one  shown  at  the  left  in  the  photo  on 
page  470  is  a  spare  set  for  use  in  case  the  large 
set  should  be  out  of  commission.   The  oil  switch 


for  the  2,300-volt  lines  is  seen  mounted  above 
the  control  panel  in  the  centre. 

THE  WIRED  RADIO  NEWSPAPER 

IN  AN  adjoining  room  is  the  automatic  ap- 
paratus which  receives  news  directly  from 
the  United  Press  Association's  offices  in  the 
World  Building,  New  York  City;  for  not  the 
least  important  part  of  the  wired  radio  service 
is  the  news  summaries  delivered  to  the  sub- 
scribers' loud  speakers  or  phones  at  the  same 
time  that  they  are  sent  to  some  seven  hundred 
newspapers  all  over  the  country.  Mr.  James 
T.  Kolbert,  of  the  United  Press  Association,  is 
Editor  of  this  newly  established  wired  radio 
newspaper. 

This  phase  of  the  service  is  not  provided  as 
a  substitute,  as  one  might  at  first  imagine,  for 
the  ordinary  daily  paper  of  wood  pulp  and 
printer's  ink.  It  is  true  that  it  supplies  news 
of  local  and  world-wide  importance,  but  it  is 
rather  as  an  arouser  of  interest  that  its  sponsors 
expect  it  to  prove  of  greatest  value.  What  is 
important  or  interesting  for  people  to  read 
about  is  told  briefly. 


468 


Radio  Broadcast 


Before  long  an  advertising  wavelength  will 
be  operated,  at  some  morning  hour  suited  to  the 
convenience  of  the  women,  who  are  the  chief 
buyers.  They  will  be  told,  by  women,  just 
where  and  when  to  shop  for  their  special  re- 
quirements. It  will  be  readily  seen  that  the 
printed  newspaper  will  always  have  the  ad- 
vantage that,  although  it  may  arrive  several 
hours  later  than  the  radio  bulletins,  it  can  be 
picked  up  at  the  reader's  pleasure,  read  as 
leisurely  and  as  often  as  may  be  desired  and 
contains  much  more  completely  the  facts  and 
discussions  that  are  broadcasted  over  the 
lighting  wires.  It  is  expected,  however,  that 
the  radio  newspaper  service  will  broaden  peo- 
ple's interests  in  a  way  that  a  daily  paper  alone 
cannot  do.  Those  whose  interests  have  re- 
volved chiefly  about  their  own  local  worlds  will 
find  themselves  following,  from  day  to  day,  in 
the  press  and  in  the  conversations  of  their 
associates,  what  the  world  at  large  is  doing  and 
thinking.  This,  if  brought  about  on  a  large 
scale  by  intelligent  and  discriminating  wired 
broadcasting,  will  be  a  tremendous  thing.  The 
instrument  is  a  powerful  one,  and  the  re- 
sponsibility that  goes  with 
the  privilege  of  using  it,  is 
great. 


and  rented  from  the  company — is  plugged 
into  one  of  his  light  sockets. 

THE  RECEIVING  SETS  SUPPLIED  TO  SUBSCRIBERS 

VARIOUS  types  of  sets  have  been  designed 
and  provided  by  Wired  Radio,  Inc.  which 
are  leased  to  subscribers  at  prices  ranging  ap- 
proximately from  two  to  five  dollars  a  month. 
(This  charge,  by  the  way,  is  tacked  on  the 
subscriber's  lighting  bill.)  All  the  sets  have 
crystal  detectors.  The  simplest  one  has  a 
semi-permanent  crystal  and  a  single  tuning 
control.  The  crystal  is  of  a  type  which  is  less 
sensitive  to  weak  signals  than  the  ordinary 
mineral,  but  equally  good  on  strong  signals; 
and  since  all  signals  received  over  the  lighting 
lines  are  as  strong  as  necessary,  this  type  of 
crystal  is  just  the  thing!  The  beauty  of  it  is 
that  after  you  have  adjusted  it  by  turning  a 
thumb-screw  slightly,  it  stays  set  for  an  indefi- 
nite period,  in  spite  of  jarring  the  table,  mov- 
ing the  set  from  place  to  place,  and  other  ac- 
tions fatal  to  the  adjustment  of  the  ordinary 
crystal.  These  sets  are  designed  for  use  with 
headphones. 


DISTANCE     MADE  POSSIBLE 
ON   A   CRYSTAL  SET 

UP  ON  the  third  floor 
of  the  broadcasting 
house  is  a  five-tube  loop 
receiver,  whose  output  may 
be  switched  directly  on  to 
the  electric  lighting  lines 
and  received  by  the  sub- 
scriber. It  need  scarcely 
be  pointed  out  that  the 
chief  significance  of  this 
phase  of  the  Wired  Radio 
Service  Company's  activi- 
ties is  that  it  makes  dis- 
tant programs  available  for 
crystal-  receivers. 

Thus,  we  find  three  dis- 
tinct sources  of  broadcasts 
— performers  in  the  studio, 
news  from  the  United  Press 
Association,  and  space  ra- 
dio re-broadcasted — all  sent 
over  the  same  lines  and 
audible  to  every  subscriber 
whose  apparatus — built  by 


JAMES  T.    KOLBERT   IN   THE   NEWS  ROOM 

This  room,  on  the  second  floor  of  the  house,  from 
which  the  wired  broadcasting  is  done,  is  connected 
directly  with  the  United  Press  Association's  offices 
in  the  World  Building  in  New  York.  Mr.  Kolbert, 
a  representative  of  the  United  Press  Association,  is 
acting  in  the  capacity  of  Editor  of  the  Wired 
Radio  News  Service 


Giving  the  Public  a  Light-Socket  Broadcasting  Service 


469 


THE  INSIDE  OF  THE  SET  SHOWN  ON   PAGE  465 

On  the  left  are  the  small  B  batteries;  at  the  bottom  is  seen  the  loud  speaker  unit  in  which  the  base  of  the  fibre  horn  is  fitted; 
the  two  WD- 1 2  tubes  and  the  crystal  (seen  at  the  extreme  right,  outside  the  cabinet)  give  one  R.  F.  stage,  detector,  and 

two  A.  F.  stages,  as  one  of  the  tubes  is  reflexed 


Most  people  prefer  to  listen  to  their  radio 
entertainment  from  a  loud  speaker  instead  of 
having  to  wear  headphones,  which  are  often 
heavy,  and,  in  summer  especially,  decidedly 
hot.  For  such  subscribers,  a  compact  little 
outfit  has  been  developed  which  reproduces 
signals  received  over  the  lighting  lines  with 
volume  sufficient  to  fill  the  ordinary-size  living- 
room.  It  contains  only  two  tubes — WD-i2's — 
but  one  of  them  is  reflexed,  so  that  the  effect  is 
obtained  of  one  radio-frequency  stage,  detec- 
tor (crystal),  and  two  audio-frequency  stages. 
This  set  is  shown  below  and  on  page  465. 

Still  another  receiving  set,  which  has  not  yet 
been  put  in  service,  has  been  designed  for  use  in 
stores,  theatres,  and  other  places  where  a 
particularly  loud  signal  is  needed.  As  in  the 
case  of  the  other  models,  the  filament  current 
will  be  supplied  from  the  lighting  wires,  and  the 
tuning  will  be  simple  enough  for  any  one  to 
master  without  much  practice  or  instruction. 
Radio  is  thus  handed  to  the  non-technical,  non- 
experimenting  "general  public"  on  a  silver 
platter.  There  is  not  much  to  go  wrong,  and 
if  anything  does,  a  man  from  the  company  will 
come  around  and  remedy  the  trouble,  like  the 
telephone  service  man.  In  other  words,  when 
a  subscriber  pays  so-much-a-month  for  a  re- 
ceiving set,  he  is  paying  at  the  same  time  for 
whatever  service  may  be  necessary  to  keep  it  in 
good  order. 

There  is  no  reason  why  one  house  should  not 


operate  several  sets  at  the  same  time  if  desired. 
No  interference  or  diminution  of  signal  results. 
And  there  is  no  reason  why  a  triple  socket,  for 
instance,  should  not  have  plugged  into  it  a 
toaster,  a  flat-iron,  and  a  receiving  set.  As  in 
the  case  of  any  other  electrical  appliance,  the 
radio  set,  when  once  connected  to  the  socket, 
is  put  in  use  simply  by  turning  on  the  electric 
light  switch. 

At  present,  all  programs  are  transmitted  on 
the  same  wavelength — about  8,000  meters — but 
the  company  expects  soon  to  operate  a  dance 
wavelength,  an  advertising  wavelength,  and  an 
educational  wavelength  simultaneously.  Prac- 
tically anything  the  subscribers  indicate  that 
they  want  in  the  way  of  programs  can  be  sup- 
plied. If  enough  of  them,  for  example,  want 
a  half-hour  talk  on  books  and  literature  each 
evening,  they  will  be  given  it  on  a  special  wave- 
length. They  will  also  be  able  to  turn  their 
single  tuning  control  to  dance  music,  which  will 
be  on  tap  practically  every  evening,  or  to  opera, 
or  lectures.  This,  it  will  be  seen,  approaches 
rather  closely  the  "fantastic"  imaginings  of 
writers  and  artists  a  few  years  ago  who  pictured 
a  small  box  from  which  all  sorts  of  entertain- 
ments could  be  drawn  at  will,  like  things  to  eat 
at  the  Automat. 

How  quickly  and  how  widely  the  public  is 
going  to  take  up  wired  radio  cannot  yet  be 
foretold  with  accuracy.  Nor  can  it  be  said 
how  cheaply  an  Ai  service  can  be  offered  to 


47© 


Radio  Broadcas: 


large  communities.  The 
cheapness  and  the  quality, 
of  course,  depend  princi- 
pally upon  the  number  of 
subscribers  obtained  in  any 
given  district.  In  New 
York  and  the  vicinity,  for 
instance,  the  best  condi- 
tions may  well  be  expected. 

Programs  originating  in 
a  wired  radio  broadcasting 
studio  in  New  York  could 
be  sent  as  far  as  Chicago  if 
it  were  necessary  to  do  so. 
But  the  difference  in  time 
in  Chicago  (which  would 
make  bedtime  stories  from 
the  Metropolitan  area,  for 
example,  an  hour  too  early 
for  the  Windy  City's 
younger  generation),  as 
well  as  the  fact  that  peo- 
ple will  generally  prefer 
programs  of  more  local  in- 
terest, make  it  unlikely 
that  wired  radio  will  ever 
tances  of  many  hundreds 
broadcasting  will  take  care  of  the  long-distance 
work  sufficiently  well. 

Wired  radio,  then,  is  not  going  to  "revolu- 
tionize" broadcasting,  since  it  differs  greatly 


THE  TRANSMITTING  SETS  AND  THE  LIGHTING  LINES 
The  small  set  at  the  left  is  for  use  principally  in  emergencies.    The  larger  set,  at 
the  right,  is  used  regularly  in  broadcasting  over  the  lighting  lines.    Above  the 
control  panel  in  the  centre  is  the  oil  switch  for  the  2300-volt  lines 


be  used  over  dis- 
of  miles.  Space 


from  "space"  radio  as  regards  the  people  it  ap- 
peals to  and  the  service  it  offers.  If  it  revolu- 
tionizes anything,  it  will  be  the  point  of  view  of 
thousands  of  people  whose  interest  will  be  stim- 
ulated in  things  worth  while,  through  a  service 
within  the  reach  of  practically  everyone. 


_____ 


BETWEEN  THE  ACTS  WITH  CYRIL  MAUDE 
The  well-known  English  actor,  who  has  been  playing  in  "Aren't  We  All?"  at  the  Gaiety  Theatre,  New  York,  tried  out  a 
receiving  set  in  his  dressing  room.    He  failed  to  hear  2LO,  near  his  home  in  London,  but  was  apparently  entertained  by 

some  local  advice  to  housewives  on  preparing  spinach 


APIA,  SAMOA — 5OOO  MILES  FROM  'FRISCO  AND  2,500  FROM  HAWAII 
A  small  group  of  enthusiastic  set-owners  at  this  remote  settlement  are  now  hearing  concerts  from  California  regularly 


When  the  Bug  Bit  in  Samoa 

The  Difficulties  of  Obtaining  Apparatus  on  a  South  Sea  Island,  Experiences 
With  Local  Red  Tape,  and  Final  Success  in  Accomplishing  5,000-Mile  Reception 

By  QUINCY  F.  ROBERTS 

American  Vice-Consul,  Apia,  Samoa 


/""""^AMOA  is  approximately  five  thousand 
miles  from  San  Francisco  and  two 
thousand   five   hundred  miles  from 

l  J  Honolulu.  Mails  arrive  twice  every 
nine  weeks.  At  the  time  of  writing, 
March  25,  1923,  I  am  reading  in  my  latest 
New  York  paper  a  program  transmitted  by 
WJZ,  forty-seven  days  ago.  The  January  is- 
sue of  Radio  Broadcast  has  not  yet  arrived. 
My  latest  radio  magazine  is  dated  February 
10,  1923,  and  I  must  await  the  arrival  of  the 
mail  steamer  sixteen  days  away  before  finishing 
a  continued  article  on  super-regeneration. 

Interesting  scenes,  places,  and  peoples  sur- 
round me.  In  the  distance,  part  way  up  the 
ridge,  I  see  the  smoke  of  Vailima,  Robert  Louis 
Stevenson's  old  home.  To  the  right  is  the 
wooded  hill  chosen  by  the  beloved  author 
for  his  tomb.  Back  of  the  Consulate  1 
hear  the  beat  of  the  hollow  log,  calling  my 
brown-skinned  neighbors  to  church.  Tofaeone, 


the  Village  Chief,  barefooted,  bareheaded,  in 
spotless  white  coat  and  lava  lava,  glancing 
aloft  to  see  if  yesterday's  storm  has  brought 
down  my  aerial,  leads  his  subjects  to  service. 

In  the  office  are  records  dating  back  to  1857. 
The  volumes  of  manuscripts  contain  the  history 
of  turbulent  Samoa — a  story  of  clashes  between 
the  Consuls,  bitter  commercial  strife,  bloody 
native  wars,  and  the  deeds  of  bold,  desperate 
men  cut  off  from  the  outer  world  without 
swift  means  of  communication.  Around  the 
point  on  the  reef  and  the  beach  lie  the  dismal 
wrecks  of  the  U.  S.  S.  Vandalia  and  the  German 
warship  Alder,  monuments  to  the  struggle  be- 
tween Germany,  Great  Britain,  and  the  United 
States  for  control  of  the  Pearl  of  the  Pacific, 
Samoa. 

Radio  in  the  stormy  past  would  have  pre- 
vented bloodshed  and  saved  the  lives  of  our 
sailors.  Wireless  would  have  created  new 
island  empires  in  the  South  Seas.    Its  use,  in 


472 


Radio  Broadcast 


fact,  would  have  changed  Pacific  history,  for 
the  naval  and  consular  authorities  of  the  inter- 
ested powers  were  without  instructions  when 
they  were  sorely  needed.  Immediate  action 
was  imperative;  decisions  were  reached  with- 
out the  guidance  of  the  home  governments. 
Radio,  annihilating  distance,  would  have  set- 
tled the  questions  between  the  nations  and 
more  than  fifty  years  of  political 
struggles  and  warfare  in  Samoa 
would  not  have  been  written. 

To-day,  Apia  is  linked  with  the 
rest  of  the  world  by  a  high-powered 
radio  station.  Its  four-hundred- 
foot  umbrella  antenna  and  its  two 
spark  sets  of  eight  and  sixty  kilo- 
watts keep  open  the  lines  of  com- 
munication with  NewZealand,  Fiji, 
Tonga, Tahiti,  Australia,  American 
Samoa,  Hawaii,  and  California. 
VMG,  as  Apia  is  known  in  the 
wireless  world,  is  the  link  between 
Paris  and  the  French  colonial  em- 
pire of  the  South  Seas.  How  differ- 
ently situated  were  my  predeces- 
sors in  the  South  Pacific  before  the 
age  of  radio,  when  telegrams  were 
dispatched  by  mail  to  Auckland, 
New  Zealand,  to  be  transmitted  by 
cable  to  Washington. 

Each  day  the  Minister  of  Ex- 
ternal Affairs  in  Wellington,  New 
Zealand,  condenses  the  world's 
news  into  a  hundred-word  radio- 
gram for  Samoa.  At  odd  moments 
between  commercial  messages  the 
operators  at  VMG  listen  in  for  the 
press  news  from  Hawaii  to  the  Far 
East.  Apia  with  its  small  weekly 
newspaper  cannot  support  a  press  service,  so 
that  the  stray  bits  of  news  collected  by  VMG 
and  the  Minister's  telegram  make  up  the 
press  news.  You  with  your  tremendous  news- 
gathering  agencies  serving  up  the  last-minute 
news  by  radio,  telegraph,  cable,  telephone, 
steamship,  railroad,  and  aeroplane,  can  little 
imagine  how  eagerly  the  short  news  bulletin  is 
assimilated  by  the  starved  whites  of  Samoa. 
People  cluster  about  the  board,  chewing  over 
and  over  the  slender  morsels,  seeking  the  inter- 
pretation of  an  obscure  phrase  or  a  missing  word 
dropped  by  an  operators'  carelessness  or  a 
crash  of  static. 

The  radio  bug,  migrating  south  and  west  from 
the  United  States,  has  reached  this  peaceful 


QUINCY  F.  ROBERTS 

Who  relates  the  exper- 
iences of  a  broadcast  fan 
miles  from  "civilization" 


island  and  a  severe  outbreak  of  radio  amateurs 
is  expected  by  the  Radio  Officer  of  Samoa. 
Eighty-four  regulations,  numerous  forms,  and 
various  licenses  are  ready  to  cope  with  the 
impending  infection. 

Some  time  ago  the  Editor  of  Radio  Broad- 
cast requested  me  to  write  an  article  on  radio 
and  its  uses  in  the  South  Seas.  He  told  me 
that  interesting  stories  of  radio  in 
places  remote  from  Manhattan  are 
appreciated  by  readers  of  the  mag- 
azine. Eight  months  ago,  when 
his  letter  arrived,  I  knew  little 
about  radio.  Of  course,  I  knew 
that  Apia  Radio  handled  my  tele- 
grams efficiently  and  supplied  me 
with  American  election  returns. 
The  operators  occasionally  called 
me  up  to  read  messages  out  of 
hours.  Now  and  then  I  had  no- 
ticed short  news  items  in  the  New 
York  papers  about  the  opening  of 
broadcasting  stations.  1  had  seen 
the  radio  programs  sent  out  by  the 
high-powered  stations  in  the  United 
States,  but  the  great  developments 
in  radio  since  my  departure  from 
the  United  States  had  escaped  me. 

My  wife  was  reading  a  letter 
from  home  when  I  happened  upon 
the  Editor's  letter. 

Looking  up,  1  casually  remarked, 
"  The  radio  craze  must  be  sweeping 
the  United  States.    Here  is  a  letter 
from  Doubleday,  Page  and  Com- 
pany  about   a   magazine  called 
Radio  BROADCASTwritten  for  radio 
fans.    Let's  get  a  radio  outfit." 
"That's  strange,"  she  replied, 
"  I  was  going  to  say  the  same  thing.    My  sister 
writes  me  about  the  concerts  she  receives  on  her 
new  radio  receiver." 

Blissful  in  our  ignorance,  we  discussed  the 
wonders  to  be  brought  about  by  the  new  in- 
strument. The  World's  news  would  be  ours. 
In  Samoa  we  would  listen  to  London,  Paris, 
Berlin,  Rome,  and  Washington.  Speeches, 
music,  and  operas  from  the  United  States 
would  break  the  monotony  of  our  island  life. 
Thus  did  the  Editor's  radio  bug  mark  two  more 
victims,  and  the  ranks  of  the  radio  amateurs 
in  Samoa  increased  three-fold. 

Then  my  hectic  life  as  a  radio  amateur  began. 
Perhaps  you  prefer  the  term  novice,  but  con- 
tinue with  me — 1  am  certain  that  you  will  ac- 


When  the  Bug  Bit  in  Samoa 


473 


cord  me  the  distinction  of  being  called  an  am- 
ateur. 

First,  I  needed  information.  The  radio  op- 
erator of  the  mail  steamer  reluctantly  left  the 
cool  shadows  of  the  village  swimming  hole  to 
have  luncheon  with  me.  Carefully  we  went 
over  the  ground.  He  said  that  1  needed  a 
good  text  book  on  radio,  a  radio  magazine,  a 
receiver  ranging  from  200  meters  to  24,000 
meters,  a  two-step  amplifier,  tubes,  batteries, 
and  telephones.  He  produced  a  worn  copy  of 
an  American  amateur  radio  magazine  pub- 
lished in  1920,  and  we  made  out  the  order 
amounting  to  $120.00  for  my  San  Francisco 
agents  to  purchase  and  ship  to  me. 

The  U.  S.  Naval  Radio  Station  at  Pago  Pago, 
American  Samoa,  supplied  me  with  Bucher's 
"  Practical  Wireless  Telegraphy"  and  1  plunged 
into  study  of  radio  theory  while  waiting  for  the 
arrival  of  my  equipment  two  months  hence.  1 
floundered  through  magnetism,  induction,  elec- 
trical measurements,  and  intricate  circuits.  I 
pored  over  diagrams  and  pictures,  trying  to 
visualize  curious  instruments  and  apparatus 
strange  to  the  South  Seas. 

I  learned  that  a  buzzer  for  code  practice 
could  be  made  from  an  electric  bell,  so  the 
beach  was  combed  for  the  bell.  Only  one  could 
be  found  in  all  Samoa,  and  as  this  was  used 
in  the  local  garage  to  test  ignition  circuits  the 


engineer  would  not  part  with  it.  At  last  I 
landed  at  the  Public  Works  Department  and 
made  known  my  want. 

Next  the  key  and  dry  cells.  The  strip  of 
brass  along  the  edge  of  the  office  rule  and  the 
handle  of  the  library  paste  brush  were  com- 
mandeered for  the  key.  The  Apia  merchants 
were  without  a  single  cell.  Their  shipments 
had  missed;  none  would  be  available  until  the 
arrival  of  the  next  mail.  Following  a  very 
slight  clew,  1  discovered  six  dry  cells  on  board 
one  of  the  copra  boats.  Considerable  argu- 
ment induced  the  owner  to  lend  me  the  cells 
until  the  arrival  of  fresh  supplies.  Code  prac- 
tice began. 

Weeks  passed  and  the  steamer  which  was  to 
bring  my  radio  set  arrived.  No  wireless  mate- 
rial was  on  the  manifest  and  there  was  not  a  line 
in  the  mail  to  tell  me  why  the  shipment  was 
not  on  the  steamer.  Three  weeks  later  a  letter 
arrived  from  Fiji  from  the  representatives  of  my 
San  Francisco  agents  saying  it  was  not  under- 
stood why  the  enclosure  was  sent  to  Fiji.  1 
looked  at  the  enclosure.  It  was  a  letter  from 
San  Francisco.  The  radio  set  would  cost 
S475.00,  consequently  new  instructions  were 
desired.  A  two-page  folder  described  the  out- 
fit. There  were  no  catalogues,  no  magazines, 
and  no  books.  1  found  the  lot  of  a  radio 
enthusiast  in  Samoa  very  hard.    Four  months 


ROBERT  LOUIS  STEVENSON'S  HOME  IN  SAMOA 
It  was  here  that  Stevenson  spent  the  last  four  years  of  his  life — 1890-1894 


474 


Radio  Broadcast 


RADIO  AMATEURS  OF  WESTERN  SAMOA 

Mr.  and  Mrs.  (Doctor  Regina  Keyes)  Roberts 
in  their  garden  at  the  American  Consulate 


must  elapse  before  the  arrival  of  my  radio 
equipment,  two  for  the  catalogues  and  two  for 
the  order  to  arrive. 

By  this  time  my  radio  education  had  shown 
considerable  progress.  Why  wait  for  a  tube 
set?  A  crystal  set  could  be  made  in  my  work 
shop  and  the  experience  would  be  useful  to  me. 
After  two  days'  search  1  found  300  feet  of 
cotton-covered  No.  18  bell  wire,  the  only  small 
wire  in  Western  Samoa.  No  one  knew  why 
it  had  been  imported.  Three  dozen  y\  inch 
brass  machine  screws,  the 
entire  stocks  of  the  garages 
and  hardware  stores  in 
Samoa,  were  purchased  for 
the  multiple  point  switch. 
Part  of  the  strip  of  brass 
from  the  office  rule  and  the 
handle  of  a  passport  visa 
stamp  completed  the  switch 
assembly.  Three  drug  con- 
tainers placed  end  to  end 
and  wrapped  in  oil  paper 
served  as  a  tube  for  wind- 
ing the  single  coil  I  planned. 
A  piece  of  galena  crystal  was 
given  me  by  the  radio  opera- 
tor on  an  American  yacht 


which  was  in  port.  The  spare  telephones  on 
board  could  not  be  purchased,  but  I  borrowed 
them  until  the  arrival  of  my  head  set.  A 
coil  of  No.  14  bronze  wire  quietly  taken  from 
the  telephone  scrap  pile  was  used  for  the 
aerial.  My  eighty-foot  flag  pole  and  a  near  by 
cocoanut  tree  served  to  support  the  antenna. 
Father  Dumas,  a  Catholic  missionary  and 
my  lone  brother  amateur  in  Samoa,  came  in 
to  inspect  my  work.  At  his  station,  forty 
miles  from  Apia  by  boat,  he  had  been  experi- 
menting with  radio  for  more  than  six  months. 
He  was  the  proud  possessor  of  a  loose-coupler, 
Baldwin  telephones,  one  variable  condenser, 
and  three  pieces  of  crystal.  He  overhauled 
my  aerial.    Critically  he  examined  my  coil. 

"A  single-wire  aerial  is  no  good,"  he  said. 
You  will  not  get  results.  The  wire  on  your 
coil  is  too  large.  The  connections  on  the 
switch  must  be  soldered." 

Mr.  Dunwoodie,  Radio  Officer  of  Samoa, 
met  me  and  said  he  heard  that  I  contemplated 
installing  a  receiving  set. 

"  Better  put  in  an  application,"  he  advised 
and  handed  me  a  long  form. 

It  called  for  my  full  name,  nationality,  the 
nationality  of  my  antecedents  for  three  gen- 
erations, my  knowledge  and  experience  with 
radio,  and  the  circuits  to  be  used.  At  the  bot- 
tom was  a  space  for  my  signature  to  the  oath 
of  secrecy  which  bound  me  never  to  divulge 
public  messages  and  never  to  permit  any  un- 
authorized person  to  use  my  equipment.  Three 
weeks  after  handing  in  my  application  I  called 
to  learn  my  fate.  The  Colonial  Secretary 
pushed  a  large  mass  of  papers  toward  me. 
It  was  my  application  with  sheet  after  sheet  of 
endorsements  and  comments  attached  to  it. 


THE  RECEIVING  ROOM  AT  STATION  VMG 


When  the  Bug  Bit  in  Samoa 


475 


NATIVE  SAMOANS  PUTTING  THE  ROOF  ON  THEIR  HOUSE 


First,  it  had  been  referred  to  the  Commissioner 
of  Police  and  the  Superintendent  of  Mental 
Hospitals  in  Samoa.  He  recommended  that  it 
be  referred  to  the  Radio  Officer  of  Samoa. 
The  Police  Department,  after  carefully  consid- 
ering the  application,  had  found  that  it  was 
without  regulations.  The  Radio  Officer  was 
without  instructions  from  New  Zealand  as  to 
the  policy  to  be  followed  in  granting  amateur 
licenses.  He  suggested  that  the  question  be 
referred  to  the  New  Zealand  Cabinet.  As  to 
the  particular  case  before  him  he  saw  no  ob- 
jection to  granting  a  temporary  permit  for  a 
crystal  set.  The  opinion  of  the  Crown  Law 
Officer  followed.  Acts  of  Parliament,  Orders 
in  Council,  decrees,  ordinances,  and  laws  were 
marshalled  in  bewildering  array.  To  my  be- 
fuddled brain  the  decision  was:  "New  Zealand 
regulations  may  or  may  not  apply  to  Western 
Samoa."  I  was  permitted  to  install  the  crystal 
set  pending  a  final  decision  from  New  Zealand. 

We  were  impatient  to  begin.  The  Samoan 
village  had  not  missed  a  move.  Village  lads 
jumped  to  stretch  the  aerial  and  make  it  fast 
to  the  top  of  the  cocoanut  tree.  Tofaeono 
called  for  his  Sunday  suit  and  his  Chief's  badge 
to  come  to  the  trial.  The  last  connections 
were  made  and  1  searched  the  crystal  for  a  good 
point.  VMG  came  in  clear  as  a  bell.  The  tele- 
phones passed  from  head  to  head.    The  air  had 


been  conquered  and  it  was  yielding  up  its 
secrets  in  dots  and  dashes.  Tofaeono  was 
elated.  The  white  man's  magic  was  in  his  vil- 
lage. His  fame  would  spread  throughout 
Samoa.  His  orators  could  boast  of  the  only 
wireless  station  outside  the  commercial  station. 
We  could  not  read  the  signals,  but  they  came 
in  strong.  My  home-made  outfit  was  a  suc- 
cess. I  did  not  learn  until  long  afterward  that 
any  coil  and  an  ordinary  land  telephone  re- 
ceiver would  bring  in  VMG's  signals. 

The  Radio  Officer  and  I  were  now  very  good 
friends.  He  respected  my  enthusiasm  if  not 
my  knowledge  of  radio.  He  agreed  to  help  me 
in  my  difficulties.  Three  new  radio  receivers 
had  arrived  for  experimental  work  at  the  radio 
station.  Concerts  were  being  tuned  in  nearly 
every  night  on  the  new  receivers.  The  op- 
erators were  enjoying  music  from  Honolulu 
broadcasting  stations.  One  of  the  new  re- 
ceivers would  go  to  Father  Dumas  and  the 
other  spare  one  could  be  sold  to  me.  Dun- 
woodie  installed  the  receiver.  Under  his  expert 
hand,  Tahiti,  Tutuila,  and  Nukualofa  came  in. 

"  Here  is  the  concert  from  Honolulu,"  he 
said,  "  But  you  will  not  recognize  it  as  a 
concert." 

1  listened.  Yes,  music  was  surging  through 
the  whistle.  Now  and  then  I  thought  I  heard 
a  word.    It  was  a  great  day  in  Samoa. 


476 


Radio  Broadcast 


)  Underwood  &  Underwood 
ONE  OF  OUR  RADIO  OUTPOSTS  IN  A   PICTURESQUE  SETTING 

A  view  of  the  harbor  and  steep  hillsides  of  Pago  Pago,  island  of 
Tutuila,  Samoa,  showing  the  towers  of  the  U.  S.  Government  station 


Since  that  time  KHJ,  KFI.and  KPO.all  Cali- 
fornia stations  and  5,000  miles  away,  have  been 
heard  many  times.  My  single-tube  regenera- 
tive set  has  grown  too  small.  1  am  now  wait- 
ing for  materials  and  supplies  for  super-regen- 
eration and  radio-frequency  amplification. 
The  radio  fever  is  in  my  veins.  More  mag- 
azines, more  books,  and  more  equipment  are 
the  only  palliatives  that  bring  relief. 

My  wife  and  Father  Dumas  and  1  are  proud 
of  the  amateur  work  in  Samoa.  We  have  no 
Radio  Relay  League,  we  do  no  DX  work  in 
the  small  hours,  we  have  no  transmitters. 
They  are  to  come.  Our  little  radio  club  of 
three  has  blazed  the  trail  for  those  who  follow 
in  our  footsteps.  Regulations  governing  the 
use  of  radio  for  experimental,  broadcasting,  or 
amateur  use  are  now  in  force  in  Western  Samoa. 
A  telephone  transmitter  is  in  Apia  for  installing 
on  the  Island  of  Savaii;  another  should  arrive 
next  week  for  the  other  side  of  Upolu.  The 
Governor  saw  our  work  and  became  convinced 


that  radio  telephony  is  feasible  for  inter-island 
communication.  Three  applications  for  receiv- 
ing permits  are  now  pending.  Other  people 
are  interested.  The  local  theater  is  planning 
to  install  radio  receivers  for  the  public.  A 
broadcasting  station  in  Samoa  is  being  dis- 
cussed. All  this  has  been  brought  about  by 
our  little  radio  club. 

Running  true  to  form  I  can  not  refrain  from 
boasting  of  my  own  achievements.  On  my  sin- 
gle-tube regenerative  set,  eliminating  all  spark 
stations  and  C.  W.  telegraphy,  1  have  logged: 
450,000  miles  in  90  days  (counting  each  station 
every  day  it  comes  in).  My  letters  to  KHJ 
reporting  the  reception  of  their  programs  at 
my  station  have  been  broadcasted  by  Uncle 
John.  Fellow  radio  fans  in  the  United  States 
have  flooded  me  with  requests  for  postage 
stamps,  seeds,  and  diagrams  of  my  circuits. 
They  say  that  one  third  of  my  results  would 
satisfy  them.  Am  I  awarded  the  title  of  ama- 
teur? 


In  the  Wake  of  the  Contest  Winners 


Four  Complete  "How-to-Make-it"  Articles  by  Run- 
ners-Up  in  the  Receiving  Contest  Who  Merit  Honor- 
able Mention.    A  Summary  of  the  Contest  Results 

In  the  August  number,  we  published  the  article  by  Mr.  Richard  Bartholomew, 
of  Porto  Rico,  which  won  the  contest  held  "to  determine  who  has  done  the  best  work 
with  any  kind  of  receiver  and  any  number  of  tubes."  Last  month  appeared  the 
second,  third,  and  fourth  prize  articles,  submitted  by  Mr.  Eric  G.  Shalkhauser  of 
Peoria,  Illinois,  Miss  Abbye  M.  White,  of  Hanover,  Pa.,  and  Mr.  Harry  Blumenfeld, 
of  Cleveland,  Ohio,  respectively.  These  four  winners  did  excellent  work,  and  we 
heartily  congratulate  them.  They  had  some  pretty  close  competitors,  too — broad- 
cast enthusiasts  who  not  only  deserve  some  recognition  of  their  efforts,  but  whose 
articles  on  construction  and  operation,  and  whose  photos  and  diagrams  are  much  too 
good  and  too  useful  for  those  of  you  who  "build  your  own,"  to  keep  out  of  the 
pages  of  Radio  Broadcast.  So  here  they  are.  We  shall  always  be  glad  to 
hear  from  readers  who  experiment  with  sets  described  in  these — or  any  other — 
articles. — The  Editor. 


AT  THE  RIGHT  YOU  SEE  THE  MAN  WHO  WON   FIRST  PRIZE 
When  Mr.  Bartholomew,  who  captured  first  place  and  the  DeForest  four-tube  reflex  loop 
set,  sent  us  his  photo,  at  our  request,  he  said,  "I'd  be  glad  to  hear  from  any  one  using  this 
circuit  of  mine  (or  better,  any  one  copying  my  set),  whether  they  have  success  or  not" 


A  Better  Broadcast  Receiver 

Mr.  Munzig  Has  Pulled  in  87,870  Miles  Worth  of  Stations  With  the  Outfit  Here  De- 
scribed, 13  Stations  Being  More  Than  2000  Miles  from  His  Home  in  Redlands,  California 

By  ARTHUR  L.  MUNZIG 

(HONORABLE  MENTION) 


NEARLY  every  old-timer  in  this 
fascinating  radio  game  has  some 
certain  method  of  radio  reception 
or  transmission  that  he  specializes 
on.  The  writer,  having  used  an 
arrangement  a  little  out  of  the  ordinary,  wishes 
to  present  to  the  readers  of  Radio  Broadcast 
a  design  he  uses  that  results  in  a  better  regener- 
ative receiver.  This  receiver  has  the  ad- 
vantages of  both  tickler-  and  tuned-plate 
methods,  oscillating  and  regenerating  over  a 
broader  waveband.  Moreover,  the  arrange- 
ment gives  increased  signal  strength  over  all 
other  methods  tried.  The  writer  frankly  be- 
lieves this  regenerative  design  to  be  the  most 
efficient  and  sensitive  regenerative  method 
now  available. 

The  one  little  instrument  in  this  receiver  that 
is  responsible  for  this  super-sensitiveness  con- 


sists of  a  variometer  with  an  inductance  coup- 
led on  to  the  left  side  of  it.  To  embrace  the 
broadcasting,  amateur  and  commercial  wave- 
lengths, 65  turns  of  No.  24  D.C.C.  copper  wire 
are  wound  on  a  tube  3^  inches  in  diameter  and 
4  inches  long.  Taps  are  taken  at  the  25th  turn 
and  at  the  end  of  the  wire  by  inserting  small 
binding  posts.  A  flexible  lead  is  then  used  to 
change  the  amount  of  inductance  desired  by 
inserting  it  in  the  first  binding  post  for  200-360- 
meter  broadcasting  and  in  the  last  post  for 
commercial  telegraph  stations  or  any  reception 
up  to  800  meters.  From  the  photo,  Fig.  1, 
the  reader  can  get  an  idea  of  how  all  this  is 
done.  The  tube  used  to  wind  the  wire  on  was  a 
salt  box.  It  would  be  better  to  use  a  fiber  or 
bakelite  tube  because  of  its  superior  insulating 
qualities.  If  the  salt  box  is  used,  however, 
take  care  to  coat  the  box  with  shellac  to  ex- 


478 


Radio  Broadcast 


FIG.  I 

Showing  how  the  inductance  is  placed  with  relation  to  the  variometer 


elude  moisture.  Using  two  small  brass  angles, 
the  inductance  is  fastened  to  the  variometer,  as 
seen  in  Fig.  i . 

If  the  reader  wants  to  include  longer  wave- 
lengths than  those  covered  by  this  receiver, 
all  that  is  necessary  to  do  is  to  wind  a  larger 
number  of  turns  on  the  salt-box  inductance. 
Bring  out  a  tap  about  every  1 5  or  20  turns  and 
fasten  them  to  contact  points  and  a  switch  on 
the  panel.  If  wavelengths  up  to  and  including 
6000  meters  are  desired,  make  the  inductance 
bank-wound1.  If  this  is  done,  don't  forget  that 
it  is  also  necessary  to  load  the  antenna  circuit. 

This  regenerative  receiver  was  originally 
designed  for  200-meter  reception,  in  which 
capacity  it  functioned  very  efficiently — but, 
with  the  advent  of  broadcasting,  a  secondary 
load  was  needed  to  tune  properly  to  these 
comparatively  longer  wavelengths;  so  an  in- 
ductance was  added  in  the  grid  circuit.  Desir- 
ing to  get  the  most  out  of  the  set  that  could  be 
had,  this  load  coil  was  placed  in  inductive  re- 
lation to  the  plate  circuit,  to  take  advantage  of 
the  radio-frequency  present.  You  can  imagine 
the  writer's  delight  when  this  resulted  in  a 
decided  increase  in  signals! 

In  Fig.  2  is  given  the  circuit  used.  Circuit 
students  will  recognize  this  as  the  Paragon  cir- 
cuit— but  with  a  few  modifications.  A  vari- 
ometer is  used  to  tune  the  plate  circuit,  while 
a  variable  condenser  and  a  secondary  load  tune 
the  grid  circuit.  Regeneration  and  oscillations 
are  obtained  by  tuning  the  plate  with  the 
variometer  and  by  having  the  grid  and  plate 
circuits  in  close  proximity. 


'Such  inductances  can,  of  course,  be  bought.  Instruc- 
tions for  bank-winding  will  be  given  in  detail  in  an  article 
by  Jesse  Marston  in  next  month's  Radio  Broadcast. — 
The  Editor. 


One  stage  of  amplification  was  all  that  was 
desired  by  the  writer,  the  assumption  being 
that  if  signals  are  audible  on  one  stage  of  am- 
plification, two  stages  increase  only  the  volume 
of  sound.  It  also  magnifies  the  noises  of  the 
tubes  as  well  as  atmospheric  disturbances.  If 
the  ear  is  subject  to  loud  signals  continuously, 
it  becomes  less  and  less  responsive  and  even- 
tually its  susceptibility  to  weak  signals  may 
be  deadened.  So  you  can  see  the  advisability  of 
no  audio  amplification  (when  using  phones), 
or  if  any,  just  one  step. 

Below  is  given  a  list  of  materials  necessary 
for  the  construction  of  this  receiver: 

1  Bakelite  panel  6"  x  21"  x  x\" 
1  White  pine  base  7"  x  20"  x  f" 
1  Large  knob  and  pointer 

1  Switch  and  contact  arm 
8  Contact  points 

2  Stops 

2  3"  knobs  and  dials 
2  Rheostats  (one  with  vernier) 
10  Nickeled  binding  posts 
1  1"  x  6"  terminal  panel 
1  Set  of  parts  for  a  Crosley  variometer 
1  Set  of  parts  for  a  Crosley  variocoupler 

1  43-plate  variable  condenser 

2  Porcelain  tube  sockets 
1  Grid  condenser 

1  Federal  amplifying  transformer 

2  Phone  condensers  (.001  mfd.) 

Enough  No.  24  D.C.C. copper  wire  to  wind  secondary  load 
Enough  No.  14  hard-drawn  bare  copper  wire  to  connect 
the  respective  parts 

Using  the  insulated  copper  wire  furnished 
with  the  variocoupler,  80  turns  are  wound  on 
the  stator  tube,  a  tap  being  brought  out  at 
every  10th  turn.  This  makes  a  total  of  8  taps, 
which  are  soldered  to  the  8  contact  points  and  . 
switch,  as  shown  in  the  circuit  diagram  in 
Fig.  2. 

Not  much  difficulty  should  be  experienced  in 
assembling  the  variometer.    Care  should  be 


A  Better  Broadcast  Receiver 


479 


[Dfl 


FIG.  2 

Mr.  Munzig's  hook-up,  a  modified  "Paragon"  circuit;  vc  may  be  omitted 


exercised  in  getting  the  rotor  and  stator  wind- 
ings wound  in  the  same  direction.  Otherwise 
their  mutual  inductance  will  not  change  and  the 
variometer  will  not  function  properly.  The 
bearings  for  the  rotor  shafts  were  not  strong 
enough  and  so  were  substituted  with  larger 
ones  cut  from  heavy  sheet  brass.  This  added 
a  rigidity  that  the  bearings  furnished  could  not 
give. 

Fig.  3  shows  the  front  view  of  the  receiver. 
An  idea  of  the  panel  layout  can  be  had  from 
this.  The  controls  from  left  to  right  are: 
coupling  control  of  the  variometer,  primary  in- 
ductance switch,  variable  condenser  control, 
detector  rheostat  control,  plate  variometer 
control,  amplifier  tube  rheostat  control,  and  the 
output  binding  posts.  The  binding  posts  at 
the  extreme  left  are:  the  upper  one  for  the  an- 
tenna and  the  lower  one  for  the  ground.  A 
variable  condenser  has  been  used  in  the  around 


for  close  adjustments — however,  it  can  be  left 
out. 

An  idea  can  be  had  from  the  photo,  Fig.  i, 
of  how  the  respective  parts  are  arranged  and 
how  connections  are  made.  No.  14  bare  cop- 
per wire  was  used  for  connections  between 
parts. 

The  variable  condenser  seen  in  Fig.  1  is  an 
old  Murdock  instrument  that  was  pressed  into 
service.  The  shaft  was  lengthened  by  solder- 
ing a  small  piece  of  the  same  size  shafting  on, 
covering  them  both  with  a  small  brass  sleeving. 
So  far  it  has  given  no  trouble. 

The  "engraving"  on  the  panel  was  done  by 
scratching  the  highly  polished  panel  with  a 
sharp  tool,  using  a  steel  rule  as  a  guide.  This 
left  a  fairly  deep  impression  into  which  white 
crayon  was  rubbed.  The  circular  arrows  were 
made  the  same  way,  but  with  a  steel  compass. 
It's  easy — try  it! 


FIG.  3 

The  dials  and  knobs,  from  left  to  right,  control:  the  secondary  of  the  variocoupler  (S  in  Fig.  2),  the  taps  on  the  pri- 
mary (P),  the  variable  condenser  (VCi ),  the  detector  tube  filament,  the  variometer  (V),  and  the  amplifier  tube  filament 


A  Set  You'll  Like  to  Make 

A  Michigan  Fan's  Complete  Data  for  Building  a  Simple 
Regenerative  Outfit.   Can  You  Do  as  Neat  a  Job  as  His? 

By  FRANK  NELEM 

(HONORABLE  MENTION) 


FOR  those  who  desire  a  receiving  set 
which  is  inexpensive,  quite  simple  in 
operation,  and  which  will  give  excel- 
lent results,  especially  on  distant  sta- 
tions, I  am  giving  a  list  of  materials 
and  detailed  instructions  for  building  and  operat- 
ing a  short-wave  receiver  of  the  single-circuit 
feed-back  type.  One  or  two  stages  of  audio 
frequency  amplification  can  very  easily  be  added 
to  it  if  desired. 
The  following  is  a  list  of  materials  needed: 

i  Panel  6"  x  21"  x  \" 

1  Variable  condenser  (vernier  adjustment  if  possible) 
4  Oz.  No.  23  single  silk  covered  magnet  wire 


2  Inductance  switches 
16  Switch  points  and  4  switch  stops 
6  Binding  posts 

1  Combined  grid  leak  and  condenser 

(grid  leak,  1  megohm;  condenser,  .0005  mfd.) 
1  Porcelain  tube  socket 
1  Vernier  rheostat 
1  UV-200  Radiotron  detector  tube 
1  .001  Fixed  phone  condenser 

This  list  of  materials  amounts  to  about  %\  5.00 
without  batteries  or  phones.  Of  course  the 
WD- 1 1  or  dry-cell  tube  may  be  used  instead  of 
the  6-volt  tube  with  fair  results,  but  personally 
1  prefer  the  6-volt  tube,  especially  for  use  with  a 
stage  of  amplification. 


STOP  STRIKES 
THIS  BOLT 


TAPS  ARE  MADE  IN  STRAIGHT 
LINE  ALONG  TOP  OF  TUBE 


LEAVE  PHONE  CORDS  LONG 
ENOUGH  TO  PERMIT  TICKLER 
ONE  FULL  TURN 


CONNECT  END  OF  THIS  SECTION  TO  FIRST 
TAP  -  OR    BEGINNING  OF  SECOND  SECTION 

/        EIGHT  TURNS   BETWEEN  TAPS 
1/2   3   4   56  7 


25  TURNS 


TICKLER  COIL 


1<o  TURNS-* 


26  TURNS 


BEARING' 
 BEGIN  WINDING  HERE 


METHOD  OF  HOLDING  BEARINGS 
IN  PLACE  BY  SOLDERING  SHORT 
HEAVY  WIRES  TO  THE   PIECE  OF 
TUBING   AND  CLINCHING  ON  THE 
INSIDE   OF  THE  COIL 


FIG.  1 

Details  of  construction  of  the  primary  coil  and  the  tickler 


A  Set  You'll  Like  to  Make 


The  set  and  its  c 
net  may  be  used 


In  regard  to  the  construc- 
tion of  this  set,  you  will  be 
well  repaid  if  you  do  the 
work  in  a  neat  manner,  sold- 
ering connections  through- 
out. Make  connections  as 
short  as  possible,  especially 
to  the  grid  and  the  parts 
which  carry  high-frequency 
current,  such  as  the  vario- 
coupler. 

MAKING  THE  VARIOCOUPLER 
PRIMARY 

WE  WILL  begin  with 
the  construction  of 
the  variocoupler:  Obtain  a 
cardboard  tube  4!"  in  diam- 
eter and  4"  long.  Soak  the 
tube  in  melted  paraffin  or 
apply  shellac  to  prevent 
shrinking.  Next  punch  or 
bore  a  hole  in  the  tube  \\"  from  the  end.  This 
hole  should  be  the  proper  size  to  take  a  piece  of 
brass  or  copper  tubing  § "  long  in  which  the  shaft 
can  be  inserted.  The  method  of  inserting  these 
bearings  will  be  easily  understood  from  the  draw- 
ings. Half  way  around  the  tube  and  1  \"  from 
the  end  punch  or  bore  another  hole  to  take  the 
other  bearing. 

Begin  winding  the  coil  with  No.  23  single  silk 
covered  wire,  as  indicated  on  the  drawings, 
about  f"  from  the  end  of  the  tube.  Run  the 
end  of  the  wire  in  and  out  of  two  pin  holes  to 
hold  it  and  wind  in  the  directions  of  the  arrows. 
Wind  on  a  section  of  25  turns  without  a  tap. 
Then  run  the  wire  along  the  tube  f "  to  the  be- 
ginning of  the  second  section.  A  tap  is  then 
made  (No.  1  in  the  drawing,  Fig.  1).  To  make  a 
tap  twist  the  wire  into  a  simple  loop  and  continue 
winding.  Wind  the  second  section  with  eight 
complete  turns.  Then  make  a  tap.  Wind 
eight  turns  more  and  make  a  tap.  Continue 
with  the  winding,  making  eight  turns  and  then  a 
tap  until  seven  eight-turn  sections  have  been 
made.  The  end  of  the  last  section  acts  as  a 
final  tap.  Secure  this  end  by  running  it  through 
pin  holes  in  the  tube. 

WINDING  THE  TICKLER  COIL 

WIND  the  tickler  coil  on  the  3"  tube,  using 
the  same  size  wire  as  on  the  primary  coil 
(No.  23  S.S.C.)  Run  the  end  of  the  wire 
through  two  pin  holes  \"  from  the  end  of  the 
tube,  leaving  about  2"  for  connection.  Now 


fig.  2 

abinet.  The  spider-web  coil  shown  in  front  of  the  cabi- 
inside  the  primary  coil  instead  of  the  cylindrical  tickler 


start  winding  in  the  direction  of  the  arrow 
shown  on  the  drawings.  Wind  on  26  turns. 
This  forms  the  first  section.  Without  cutting 
the  wire,  keep  on  winding  diagonally  across  the 
space  between  the  sections  on  the  back  of  the 
tube.  (This  is  shown  by  the  dotted  line  in  the 
drawing  of  the  tickler  coil.)  Keep  this  wire  well 
away  from  the  holes  for  the  shaft.  The  wire 
may  be  held  in  place  by  a  drop  or  two  of  sealing 
wax.  Then  begin  winding  the  second  section, 
being  careful  to  start  this  section  the  same  dis- 
tance from  the  centre  of  the  tube  as  the  last  turn 
of  the  first  section.  Wind  26  turns  and  pass  the 
end  through  two  pin  holes  made  in  the  tube. 
Leave  about  2"  for  connecting.  About  1" 
above  the  \"  hole  that  the  shaft  passes  through, 
bore  a  hole  and  insert  a  4"  piece  of  telephone 
cord  or  other  wire  that  is  quite  flexible.  This 
cord  or  other  wire  should  be  soldered  to  the  2"  of 
wire  (inside  the  tube)  at  the  beginning  of  the 
winding.  The  telephone  cord  may  be  held  by 
a  drop  of  sealing  wax  where  it  passes  through  the 
tube.  Bore  a  hole  below  the  hole  for  the  shaft 
and  insert  another  piece  of  telephone  cord. 
Solder  this  to  the  end  of  the  second  section. 


T! 


THE  SPIDER-WEB  TICKLER 

HERE  is  another  tickler  coil  which  is 
equally  satisfactory,  if  properly  constructed. 
That  is  the  spider-web.  If  you  want  to  use  it, 
instead  of  the  tickler  coil  just  described,  cut  out 
a  disc  from  cardboard  which  just  clears  the  in- 
side of  the  primary  nicely.    By  cutting  off  the 


482 


Radio  Broadcast 


shaft  and  slotting  the  ends  with  a  hacksaw  the 
coil  may  be  held  in  place  so  as  to  rotate  inside 
the  primary.  Cut  any  odd  number  of  slots  in 
the  disc  (1  used  7 — see  Fig.  2),  and  wind  the 
wire  in  and  out  through  the  slots  until  all  the 
wire  possible  is  wound  on  (about  40  turns). 
Connect  the  two  ends  to  pieces  of  telephone 
cord.  It  will  be  found  that  this  tickler  will  give 
more  selective  tuning  on  account  of  preventing 


screws  against  the  sides  of  the  cabinet.  This 
feature  makes  it  very  easy  to  remove  the  set 
from  its  cabinet.  The  panel  is  screwed  to  the 
edge  of  the  base. 

Place  the  variocoupler  in  position  as  close  to 
the  end  of  the  base  as  possible  so  the  tickler  coil 
will  clear  the  side  of  the  cabinet  when  turned. 
Now  slip  the  base  blocks  under  the  ends  of  the 
variocoupler  and  locate  on  the  panel  the  hole  for 


FIG.  3 

A  neat,  attractive  panel,  with  room  at  the  right  for  the  additional  peep- 
holes, phone-jack  and  rheostat  needed  if  a  step  of  amplification  is  added 


electrostatic  coupling  and  increasing  the  electro- 
magnetic coupling. 

ASSEMBLING  THE  VARIOCOUPLER 


long,  has  two 


THE  shaft,  which  is  about  7 
small  holes  bored  near  the  back  end.  The 
stop  wire  runs  through  one  hole  and  strikes 
against  a  small  bolt  or  switch  point.  A  small 
key  is  inserted  on  the  inside  of  the  bearing  to 
prevent  the  shaft  from  slipping  endways.  The 
tickler  coil  is  secured  by  a  small  wire  running 
through  the  shaft,  the  ends  just  passing  through 
the  tube. 

First  run  the  telephone  cords  attached  to  the 
tickler  coil  through  two  holes  in  the  primary 
tube.  One  of  these  holes  is  above  and  the  other 
below  the  bearing,  or  if  preferred  the  cords  may 
be  held  with  a  small  bolt  inserted  in  the  holes. 
Next  slip  the  shaft  through  the  bearings  and  the 
tickler  coil.  Fasten  the  stop  and  pin  in  the 
holes  at  the  end  of  the  shaft,  and  secure  the 
tickler  coil  by  a  small  wire  running  through  the 
tube  and  shaft.  The  variocoupler  rests  upon 
two  small  base  blocks  of  wood  or  fiber. 

ASSEMBLING  THE  SET 

OBTAIN  a  board  for  the  base  about 8" wide 
and  |"  thick.  Cut  to  a  length  that  will 
just  nicely  slide  into  the  cabinet.  This  board 
is  somewhat  shorter  than  the  panel,  as  the  panel 


the  shaft  turning  the  tickler.  The  hole  for  the 
shaft  of  the  variable  condenser  should  be  on  a 
line  with  that  of  the  tickler  and  the  two  shafts 
about  6"  apart.  The  dials  are  about  3"  in 
diameter.  Unscrew  the  panel  from  the  base. 
Bore  the  holes  for  tickler  and  condenser  shafts. 
Centre  the  two  inductance  switches  and  bore 
the  holes.  Bore  eight  holes  for  each  row  of 
switch  points  so  that  the  heads  of  the  switch 
points  will  not  be  too  far  from  each  other  for  the 
switch  lever  to  pass  smoothly  over  them.  Bore 
also  the  holes  for  the  switch  stops.  The  small 
knob  at  the  lower  right  of  the  condenser  dial 
in  the  photograph  (Fig.  3)  is  a  homemade  fric- 
tion vernier  attachment  made  from  a  binding 
post  cap  and  a  short  piece  of  threaded  shaft.  A 
rubber  disc  rubs  on  the  edge  of  the  dial.  This  is 
almost  a  necessity  unless  one  has  a  vernier  con- 
denser, as  very  sharp  tuning  is  required.  Bore 
the  holes  for  the  rheostat  next,  placing  it  as  near 
to  the  condenser  as  possible  without  interference. 
The  phone  jack  is  optional  but  is  necessary  for  a 
stage  of  amplification.  Bore  the  holes  for  the 
six  binding  posts:  aerial,  ground,  phones  and  A 
battery.  The  phone  condenser  is  of  the  paper 
and  tinfoil  type.  Mica  and  copper  are  con- 
sidered a  better  combination  but  this  type  has 
worked  satisfactorily  for  me. 

Glue  tinfoil  on  the  back  of  the  panel  to  act  as 
a  shield  for  body  capacity.    This  runs  just  as 


A  Set  You'll  Like  to  Make 


483 


far  as  the  rheostat.  Cut  the  tinfoil  away  from 
all  metal  shafts  and  rows  of  Switch  points  by  a 
margin  of  at  least  f".  Also  cut  it  from  around 
the  aerial  binding  post,  but  do  not  cut  it  away 
from  the  ground  binding  post  as  it  must  make 
contact  with  the  ground.  Shielding  must  be 
done  carefully,  for  if  the  tinfoil  touches  a  shaft 
or  screw  the  set  may  fail  to  operate. 

After  this  is  done,  screw  the  switch  points  in 
and  put  in  the  inductance  switches.  Run  a 
wire  from  the  ground  binding  post  to  the  upper 
inductance  switch  and  solder  it.  Bare  wire 
covered  with  rubber  tubing  or  spaghetti  may  be 
used  throughout.  The  wire  used  in  this  set  is 
No.  18  covered  with  black  cotton.  Cut  eight 
pieces  of  wire  about  eight  inches  long.  Take 
one  of  these  and  solder  one  end  to  the  first 
switch  point  in  the  lower  row.  Run  this  wire 
up  to  the  first  switch  point  in  the  upper  row. 
Leave  about  five  inches  for  connection  to  the 
first  tap  on  the  variocoupler.  Connect  up  the 
two  rows  of  switch  points  in  this  manner.  The 
second  switch  point  in  the  upper  row  connects  to 
the  second  in  the  lower  row.  Solder  one  end  of 
a  wire  to  the  lower  inductance  switch  and  leave 
the  wire  long  enough  to  reach  the  lower  binding 
post  at  the  right  of  the  panel. 

The  panel  may  now  be  mounted  on  the  base 
board.  Place  the  variocoupler  on  the  base 
board  with  the  shaft  through  the  hole  in  the 
panel  and  with  the  dial  attached  move  the  vario- 
coupler until  it  rests  level  and  square  with  the 
panel.  Fasten  it  to  the  base  with  wood  screws 
running  through  the  base  blocks.  Solder  the 
wires  from  the  upper  row  of  switch  points  to  the 
taps  in  the  coil,  the  first  switch  point  to  the 
first  tap,  etc. 


^  fig.  4 

This  single-circuit  regenerative  hook-up  is  about  the 
simplest  tube  hook-up  there  is.  It  is  not  recommended 
in  thickly-populated  districts,  because  it  causes  inter- 
ference by  re-radiation;  but  it  is  very  efficient  and  just 
the  thing  for  the  person  who  lives  in  the  country  and 
hasn't  much  to  spend  on  a  set 


Connect  the  aerial  binding  post  to  the  rotary 
plates  of  the  variable  condenser.  Run  a  wire 
from  the  stationary  plates  of  the  variable  con- 
denser to  the  beginning  of  the  primary  winding. 
Connect  the  plate  terminal  of  the  vacuum  tube 
socket  to  the  lower  terminal  of  the  tickler  coil. 
Run  a  wire  from  the  upper  binding  post  and 
phone  condenser  over  to  the  upper  terminal  of 
the  tickler  coil.  Connect  the  wire  soldered  to 
the  lower  inductance  switch  to  the  lower  right 
hand  binding  post  which  will  be  a  positive  A 
battery  terminal.  Connect  the  positive 
("plus")  terminal  of  the  socket  to  this  wire. 
Run  a  wire  from  the  negative  side  of  the  socket 


fig.  5 

Mr.  Nelem  purposely  made  his  panel  21  inches  long,  so  that  he  could 
add  a  step  of  audio-frequency  amplification  when  he  wanted  to 


484 


Radio  Broadcast 


to  the  rheostat  and  one  from  the  rheostat  to  the 
negative  A  battery  binding  post,  which  is 
second  from  the  bottom.  The  negative  pole 
of  the  B  battery  connects  on  the  positive  A  or 
bottom  post.  The  positive  B  goes  to  the  phone 
condenser.  The  grid  leak  and  condenser  con- 
nect to  the  beginning  of  the  primary  winding. 
Constant  reference  to  the  three  photographs 
and  the  diagrams  should  enable  any  one  who 
follows  these  instructions  carefully  to  build  a 
set  like  mine  without  difficulty. 

OPERATION  OF  THE  SET 

WH  EN  tuning  in  a  broadcasting  station  set 
the  inductance  switches  on  about  the 
fourth  points  (with  a  hundred-foot  aerial). 
Turn  on  the  rheostat  until  the  bulb  starts  to 
hiss.  Then,  with  the  tickler  coil  lying  hori- 
zontally, turn  the  variable  condenser  around 
slowly  being  careful  not  to  pass  over  the  signals. 
If  this  does  not  bring  in  signals,  turn  the  tickler 
coil  half  way  over  and  try  again.  It  will  be 
found  that  the  condenser  will  be  used  most  in 
tuning.  When  the  condenser  is  at  zero  capac- 
ity a  very  loud  howl  will  be  heard  in  the  phones. 
The  use  of  the  vernier  rheostat  must  not  be 
slighted,  however,  as  this  will  give  clearness  of 
tone  and  help  to  prevent  howling.    Do  not 


turn  the  rheostat  on  too  far.  If  the  grid  leak  is 
of  the  right  resistance,  a  sharp  click  will  be 
noticed  when  turning  on  the  rheostat.  Keep  the 
filament  current  just  below  this  click  to  get  the 
strongest  and  clearest  signal. 

I  have  used  the  electric  light  wiring  in  the 
house  for  an  aerial  and  find  that  it  is  almost  as 
good  as  my  outside  aerial  which  is  about  100 
feet  long  and  30  feet  high.  With  one  stage  of 
audio-frequency  amplification  I  have  heard 
stations  in  Los  Angeles  (from  my  home  in  East 
Tawas,  Michigan)  using  the  light  wires  as  an 
aerial  and  the  bed  springs  as  a  counterpoise. 
Using  the  light  wires  as  an  aerial,  I  have  con- 
nected one  wire  to  either  the  centre  or  side 
contact  in  the  electric-light  socket  and  run  this 
wire  to  the  set,  turning  on  the  switch  in  the 
lamp  socket.  The  variable  condenser  stops 
any  current.from  passing  into  the  set.  By  con- 
necting the  ground  to  the  aerial  binding  post 
I  have  heard  stations  500  miles  distant.* 

One  stage  of  amplification  can  very  easily  be 
added  at  the  right  of  the  detector  tube.  It 
was  with  the  idea  of  this  addition  that  the 
panel  was  made  21  inches  long. 

*Mr.  Nelem's  total  mileage  is  61,100 — 92  stations 
over  150  miles  distant,  of  which  four  were  2000  miles  or 
over. 


A  Set  With  a  Tuned  R.  F.  Amplifier 

A  Non-Regenerative  Outfit  Designed  Primarily  for  Quality,  Not  Quantity 

By  J.  W.  DENNING 

{HONORABLE  MENTION) 

T'HEN  a  radio  fan's  craving    giving  good  quality  of  reproduction,  plenty  of 
/  for  distance  and  innumerable    volume,  and  which  does  not  require  continual 
k  /    new   stations   is   satisfied —    manipulation  to  keep  it  in  tune,  soon  become 
as  it  always  is  sooner  or  later    apparent  to  him. 

The  writer  some  time  ago 
found  himself  converted  to  this 
attitude,  and  the  receiver  herein 
described  is  a  result  of  consider- 
able study  on  the  matter.  It 
was  early  recognized  that  re- 
generation, while  able  to  cover 
great  distances  and  with  proper 
amplification  giving  good  vol- 
ume, at  its  best  was  unstable 
and  tended  to  distort.  R.  F. 
amplification  seemed  to  offer  a 
way  out  of  these  difficulties. 


— he  begins  to 
study  methods  of  improving  the 
quality  of  what  he  receives  and 
the  stability  of  his  set.  The 
single-tube  set  which  he  usually 
starts  with  does  not  satisfyhim, 
and  he  begins  to  tack  on  more 
tubes  and  try  all  sorts  of  hook- 
ups. Certain  stations  become 
old  friends  to  him — he  tunes  in 
on  them  regularly  and  often 
listens  to  them  until  they  sign 
off.    The  advantages  of  a  set 


THE   "QUALITY  FIRST"  BOX 
It  has  4  tubes,  no  regeneration 


A  Set  With  a  Tuned  R.  F.  Amplifier 


485 


45  V. 


The  grounded  side  of  condenser  Ci  is  the  rotar.  A  plug  and  jack  arrangement,  or  a  double-pole  double- 
throw  switch,  may  be  used  to  advantage  for  quickly  changing  from  antenna  and  ground  to  the  loop,  L3 


All  the  available  commercial  R.  F.  sets  were 
carefully  studied  and  various  R.  F.  transformers 
experimented  with  as  they  came  on  the  mar- 
ket. It  was  found  that,  while  several  untuned 
types  of  transformers  worked  very  satisfactor- 
ily they  required  a  highly  selective  tuner  with 
rather  loose  coupling.  Since  loose  coupling 
meant  a  reduction  of  transferred  energy,  a 
method  of  obtaining  selective  tuning  with  a 
single-circuit  aerial  tuner  was  sought,  and 
found  in  the  tuned  transformer  and  tuned 
impedence  methods  of  radio-frequency  am- 
plification. The  latter  method  was  adopted 
as  being  simpler  than  the  tuned  transformer 
and  equally  efficient.  An  added  feature  was 
its  adaptability  to  any  type  of  tube,  which  was 
not  the  case  with  transformers,  making  it 
possible  to  use  dry-cell  tubes  when  so  desired. 
The  set  illustrated  is  one  of  a  number  con- 
structed on  this  principle,  all  of  which  have 
given  entire  satisfaction. 

Refering  to  the  circuit  diagram,  the  principal 
constants  are  as  follows: 

Li — A  well  built  variometer  wi;h  a  fairly  large  range 
of  inductance  to  cover  a  wide  band  of  wavelengths. 

— A  honeycomb  coil  of  35,  50,  or  75  turns,  set  so  that  it 
will  not  be  too  closely  coupled  inductively  to  Li. 

L3 — Loop  aerial  for  "static  nights",  10  to  12  turns,  flat 
wound,  two  feet  on  a  side.  It  may  be  used  with  the  outside 
aerial  as  indicated. 

Ci — n-plate  variable  condenser,  giving  fine  tuning  in 
aerial  circuit.  Note:  a  series-parallel  switch  will  increase 
the  wavelength  range  of  this  set  very  much  when  used  with 
this  condenser  and  Lj. 

C2 — 23-plate  variable  condenser,  preferably  with  vernier, 
used  to  tune  Ls  to  resonance  with  the  grid  circuit. 

C3 — Fixed  grid  condenser  of  fro:n  .00025  mfd.  to  .0005 
mfd.    It  should  be  a  good  mica  co  idenser. 

C4 — Fixed  phone  by-pass  condenser,  capacity  .001  mfd. 


Ri — 200-  t0400-ohm  potentiometer,  used  to  control  regen- 
erative tendency  of  amplifier  tube  and  prevent  oscillations. 

R.2,  R4 — 6-  to  25-ohm  rheostats,  depending  on  tubes  used. 

R3 — 6-ohm  rheostat  for  detector  filament.  Vernier  helps 
if  detector  is  soft. 

R5 — I  to  5  megohms.  This  is  the  grid  leak  for  the  de- 
tector tube  and  is  preferably  a  good  variable  leak. 

The  tubes  recommended  for  best  results  are 
as  follows: 

Detector:  soft  tube  such  as  UV-200. 
A.  F.  Amplifiers:  Hard  tubes  such  as  UV-201  or  20I-A. 
or  De  Forest. 

R.  F.  Amplifier:  Hard  tube  such  as  UV-201  or  201-A. 
The  201  seems  to  work  as  well  as,  if  not  better  than  the 
201-A. 

WD-i  1,  WD-12,  or  UV-199  tubes  may  be  used  if  desired, 
although  they  are  not  as  good  amplifiers  as^  the  above 
mentioned  tubes. 

It  will  be  noted  that  a  separate  plate  lead  is 
brought  out  for  the  radio-frequency  tube.  It 


fig.  2 

Showing  relative  positions  of  the  various  units 


486 


Radio  Broadcast 


FIG.  3 

The  set  of  Fig.  2  has  been  tipped  back,  to  show  the 
transformers,  mounted  under  the  shelf  which  is  fastened 
in  back  of  the  panel 


will  be  found  that  this  tube  will  operate  best 
at  a  lower  voltage  than  the  A.  F.  tubes.  A.  F. 
transformer  filament  leads  should  be  connected 
to  the  negative  of  the  A  battery  with  the  rheo- 
stat in  the  negative  lead  to  the  sockets.  The 
grid  leak  should  run  to  the  positive  terminal 
on  the  detector  socket. 

TUNING 

THE  principle  involved  is  this:  when  the 
grid  circuit  and  plate  circuit  are  both  in 
tune  with  the  incoming  signal  only  the  signal 


tuned  to  will  be  amplified,  all  others  "falling  by 
the  wayside."  It  is  important  that  the  dis- 
tributed capacity  in  Lz  and  L2  be  low,  thus 
giving  the  sharpness  of  tuning  which  is  so  much 
desired.  By  setting  the  potentiometer  as  near 
the  negative  as  possible  without  starting  oscil- 
lations and  moving  L,  and  C2  simultaneously, 
the  corresponding  resonance  positions  will  soon 
be  found  and  stations  easily  tuned  in.  Fine 
tuning  is  done  with  Q  and  the  vernier  on  C2. 
This  set  will  usually  operate  best  with  low  values 
of  d,  on  the  outside  aerial,  and  medium  values 
when  used  with  the  loop.  (This  can  be  accom- 
plished by  careful  adjustment  of  the  variometer.) 
Careful  setting  of  Rt  makes  for  maximum 
amplification.  It  should  be  turned  as  far  to 
the  negative  side  as  possible  without  producing 
oscillations.  Oscillations  are  manifested  by 
the  set  suddenly  "going  dead,"  an  effect  which 
can  be  easily  identified.  When  oscillating,  it 
makes  a  very  good  receiver  of  undamped  waves. 
Since  phone  signals  cannot  be  received  when 
the  set  is  oscillating,  there  is  no  inclination  to 
use  it  in  the  oscillating  condition  on  broadcast 
reception,  hence  it  does  not  cause  interference 
as  regenerative  sets  often  do. 

Although  the  writer  isn't  much  of  a  "radio 
golfer,"  some  of  his  friends  have  made  very 
creditable  records  in  an  evening  with  the  set 
just  described.  The  total  mileage  is  71,125, 
with  89  stations  logged,  the  farthest  (from 
Boulder,  Colorado)  being  PWX  in  Havana. 


A  Home-Made  Three-Tube  Outfit 


It  is  Easy  to  Build  and  Easy  to  Operate.  It  Has  Brought  in  100  Stations, 
Two  of  Them  Being  2000  Miles  from  the  Writer's  Home  in  Marion,  Indiana 

By  L.  REITH 

(HONORABLE  MENTION) 


7""^HIS  set  is  made  up  of  three  parts — 
tuner,  detector,  and  two  stage  am- 
plifier. It  is  very  efficient  and  se- 
lective, easy  to  tune  and  works 
equally  well  on  all  wavelengths  from 
1 50  to  700.  It  works  better  than  several  other 
sets  I  have  made,  running  from  single  circuits 
to  the  variometer  and  variocoupler  hook-up, 
and  has  given  excellent  results  from  the  very 
first  minute  it  was  tested  out. 

The  tuner  circuit  is  composed  of  a  station- 
ary primary  coil,  movable  secondary  coil  in 


inductive  relation  to  the  primary,  a  station- 
ary secondary  loading  coil  in  series  with  the 
secondary,  a  movable  tickler  coil  in  the  second- 
ary loading  coil,  and  a  23-plate  variable  con- 
denser. 

For  the  primary  coil,  wind  65  turns  on  a  tube 
35"  in  diameter  and  2j"long,  tapping  at  turns 
15,  18,  2 1 ,  24,  27,  30,  35,  40,  45,  50,  55,  60  and 
65,  making  13  taps. 

The  secondary  loading  coil  is  wound  with  38 
turns  on  a  tube  3§"  in  diameter  and  if"  long, 
tapping  the  tenth  and  the  last  turns. 


A  Home-Made  Three-Tube  Outfit 


487 


THE  OUTFIT  COMPLETE,  AND  READY  TO  FURNISH  AN   EVENING'S  ENTERTAINMENT 

In  the  left-hand  cabinet  are  the  tuning  units  only,  in  the  middle  one  is  the  de- 
tector, and  in  the  right-hand  cabinet  are  the  two  steps  of  A.  F.  amplification 


These  two  coils  are  mounted  on  the  panel  at 
right  angles  as  shown  in  one  of  the  photos,  with 
small  brass  angles  or  pillars  so  as  to  set  them 
back  \"  from  the  panel. 

The  secondary  and  tickler  coils  are  exactly 
alike,  being  3"  in  diameter  and  1  \"  long,  wound 
in  two  sections,  each  §"  long,  with  a  space  of 
\"  between  to  allow  for  the  shaft.  The  shafts 
are  made  of  fV'  brass  rod  5"  long,  threaded 
on  one  end  for  about  one  inch,  and  from  the 
other  end  up  to  the  thickness  of  the  panel  from 
the  first  threads.    This  small  place  left  is  for 


the  bearing  on  the  panel.  If  this  bearing  is 
carefully  made,  no  rear  support  for  the  shaft 
will  be  needed.  It  is  a  good  plan  to  use  a  panel 
bushing  such  as  those  on  switches,  but  if  these 
are  not  at  hand,  screw  on  the  short  threaded  end 
of  the  shaft  a  nut  as  tight  as  it  will  go,  put  the 
shaft  through  the  hole  in  the  panel  (be  sure 
that  it  is  not  a  bit  larger  than  necessary  for  the 
rod  to  slip  through)  and  put  two  nuts  on  the 
other  side  of  the  panel,  using  the  last  one  as  a 
lock-nut.  Get  them  close  enough  to  the  panel 
to  make  a  good  bearing  for  the  shaft.    It  is  well 


45  v. 


FIG.  I 


P-primary  coil,  S-secondary  coil,  SL-secondary  loading  coil,  T-tickler,  Si-switch  for 
cutting  in  inductance,  C-23-plate  condenser  with  rotor  grounded,  Pi-potentiometer 


488 


Radio  Broadcast 


FIG.  2 

Showing  bearing  for  movable  coils 


to  include  washers  next  to  the  panel  on  both 
sides.  Then  put  on  the  coil,  using  a  nut  on 
each  side  of  the  tube  at  both  places  where  it 
goes  over  the  shaft  to  hold  it  in  place.  These 
should  be  placed  to  hold  the  coil  in  the  right 
position  for  turning  without  touching  the  larger 
coils.  Run  leads  from  the  coils  to  their 
proper  connecting  places.  All  winding  was 
done  with  20-strand  No.  38  Litzendraht. 

The  detector  and  amplifier  are  of  standard 
construction  and  hook-up.  The  list  of  ma- 
terials needed  for  this  set  is  as  follows: 

1  tube,  3'"  dia.  and  2j"  long 

.    "     W         "    >i"  " 

2  "     3"  "    \\"  " 
2  brass  rods,  TV  x  5" 

2  switch  levers 

1  23-plate  variable  condenser 

3  3"  dials 

1  potentiometer 

1  Bradleystat 

2  rheostats 

3  sockets 

2  two-circuit  jacks 

1  one-circuit  " 

2  amplifying  transformers 

1  .001  mfd.  fixed  condenser 
1  grid  leak  and  condenser 
200  ft.  20  No.  38  Litzendraht 


Connecting  wire 
Switch  points 
Binding  posts 
Panels 

Miscellaneous  bolts  and  nuts 

INSTRUCTIONS  FOR  OPERATING 

USING  dials  with  a  90-degree  scale,  0-50, 
set  so  that  they  are  at  o  with  both  coils  in 
a  vertical  position.    Then  proceed  as  follows: 

Set  the  secondary  dial  at  about  40  and  the 
tickler  dial  at  about  the  same.  These  will  be 
approximately  the  best  positions  for  these  dials 
on  all  wavelengths.  Then  set  the  switches  on 
taps  best  for  the  particular  wave  wanted;  for 
example,  for  360  or  400  meters,  put  the  primary 
on  tap  7  and  the  secondary  on  tap  2.  The 
best  positions  for  these  will  be  easily  found  after 
a  little  experimenting.  Turn  the  rheostats  up 
until  oscillation  just  begins,  and  move  the  con- 
denser dial  until  you  get  a  carrier-wave  squeal. 
Tune  as  well  as  possible  with  this  and  finish 
tuning  with  the  secondary  dial,  as  this  acts  as  a 
vernier  on  the  condenser  and  will  give  very  fine 
tuning.  Adjust  the  tickler  so  that  the  signals 
are  loudest  without  distortion.  Waves  up  to 
300  meters  come  in  best  in  my  case  with  the 
secondary  switch  on  tap  1 ;  over  300,  on  tap  2. 

On  the  end  of  the  amplifier  box  are  a  switch 
and  binding  posts  for  connection  to  a  loud- 
speaker if  wanted,  so  that  either  it  or  the  phones 
or  both,  may  be  used. 

A  good  loud  speaker  can  be  made  by  getting 
an  old-style  phonograph  horn  and  soldering  on 
it  a  bracket  and  a  plate  or  can  lid  large  enough 
to  take  a  receiver  and  with  a  hole  just  the  size 
of  the  neck  on  the  horn.  Put  a  piece  of  felt  on 
this  and  clamp  the  receiver  on  with  rubber 
bands  or  any  kind  of  clamping  device. 


THE  OUTFIT  OPEN   FOR  INSPECTION 


■ 


Summary  of  Receiving  Contest  Entries 
Arranged  in  Order  of  Mileages 

The  following  report  includes  the  work  of  all  contestants  having  a  total  mileage  of 
40,000  or  over,  but  does  not  include  the  Pri^e  Winners  or  Honorable  Mentions: 


JOHN  C.  Peters,  Casper,  Wyoming.  305,420 
miles.  His  receiver  employs  the  principle  of  "re- 
sistance neutralization"  developed  by  his  brother, 
Leo  J.  Peters,  Radio  Research  Engineer  for  the 
University  of  Wisconsin.  For  information  regard- 
ing this  principle,  Mr.  Peters  refers  us  to  the  Journal 
of  the  A.I.E.E.,  Vol.  41,  March,  1922. 

Otho  Currie,  3305  Avenue  H,  Fort  Worth,  Texas. 
283,330  miles.  One-tube  single-circuit  regenerator. 
He  has  heard  every  state  in  the  U.  S.,  10  stations 
in  Canada,  1  in  Porto  Rico,  2  in  Hawaii,  1  in  Alaska, 
and  1  in  Cuba. 

Milton  S.  Johnson,  938  So.  4th  St.,  Atchison, 
Kansas.  199,988  miles.  3-circuit  set  using  one 
step  of  radio,  detector,  and  one  audio.  He  com- 
ments on  the  "great  feeling,  to  be  able,  any  ordinary 
evening,  to  slip  your  phones  on  your  ears  and  listen 
to  any  one  of  the  better  class  broadcasting  stations 
in  the  United  States."  However,  he  remarks: 
"1  have  made  one  discovery  and  that  is  that  the 
real  fun  in  radio  is  to  have  a  C.W.  and  'fone'  trans- 
mitter, belong  to  the  A.R.R.L.,  and  talk  back  and 
forth  to  China  and  London."  Yes,  we  have  no 
objections. 

Leland  K.  Hill,  Wellsville,  Utah.  179,588  miles. 
Single-circuit  regenerative  set  with  a  two-stage  home- 
made amplifier.  During  the  cold  weather  nights  he 
has  stayed  up  into  the  small  hours  and  heard  a 
number  of  2000-mile  stations,  the  farthest  being 
Halifax,  Nova  Scotia,  2490  miles  from  Wellsville. 

Captain  J.  H.  Halsev,  skipper  of  the  S.  S.  El 
Cid,  which  runs  between  New  York  and  Galveston, 
Texas,  made  his  own  3-tube  outfit  in  conjunction 
with  a  friend.  172,960  miles.  "We  average  eigh- 
teen nights  a  month  at  sea,"  he  writes,  "where  we 
have  a  very  clear  atmosphere.  The  antenna  runs 
from  masthead  to  masthead,  above  the  ship's  an- 
tenna, and  direct  to  my  cabin.  The  set  is  surely 
good  company." 

Fergus  Sunshine  McKeever  (age  12),  University 
Heights,  Lawrence,  Kansas.  170,000  miles.  Grebe 
CR-9  (three-tube  regenerative  set),  with  Baldwin 
phones  and  a  W.E.  loud  speaker.  This  youthful  con- 
testant has  "listened  as  late  as  three  o'clock  getting 
65  stations  in  one  evening."  He  claims  to  have  heard 
a  station   in  Portugal,  one  fine  winter's  night. 

Arthur  Chapelle,  Woodburn,  Ore.  168,690  miles. 
Three-circuit,  tickler  regenerative  set,  two  tubes. 
Mr.  Chapelle  sent  us  one  of  the  excellent  spider- 
web  coils  which  he  makes  himself,  and  to  which 
he  ascribes  much  of  his  s"~cess  in  pulling  in  far- 
away stations. 


E.  Woody  Kulman,  1046  36th  St.,  Des  Moines, 
Iowa.  148,255  miles.  His  home-made  recever,  of 
the  standard  single-circuit  type,  cost  him  $37.40.  He 
observes  that  Des  Moines  has  a  conveniently  central 
location  for  reception  from  all  points  of  the  compass. 

J.  B.  Slaughter,  Jr.,  U  Lazyc/)  Ranch,  Post,  Texas. 
147,680  miles.  He  has  heard  203  different  stations, 
all  on  a  3-tube  set  with  a  Magnavox  R  loud  speaker. 
"Radio  on  the  ranch,"  says  Mr.  Slaughter,  "is  the 
greatest  invention  yet,  for  ranchers,  as  a  rule,  are  a 
great  distance  from  any  entertainment  or  late  news 
of  any  sort;  with  the  coming  of  radio  we  are  right 
alongside  the  large  cities.  We  get  the  baseball 
results,  for  instance,  even  before  they  do,  unless 
they  have  radio  sets  installed.  The  broadcasting  of 
cattleand  crop  quotations  is  very  valuableon  ranches, 
as  we  can  tell  better  when  to  ship  our  cattle  and 
grain.  Any  one  ever  in  this  part  of  the  country  is 
extended  a  cordial  invitation  to  visit  the  ranch  and 
see  my  set." 

T.  W.  Sharpe,  Jr.,  (age  15),  1816  North  Colorado 
St.,  San  Antonio,  Texas.  147,325  miles.  Detector 
and  two  of  audio  again,  with  an  improvised  loud 
speaker  to  which  the  headphones  are  attached. 

W.  E.  Davison,  538  Charlotte  St.,  Sydney,  Nova 
Scotia.  He  has  tried  many  circuits  but  finally 
settled  on  the  common  or  garden  variety  of  single- 
circuit  regenerative  hook-up,  which,  it  is  to  be  hoped, 
causes  less  interference  in  Novia  Scotia  than  it  does 
in  other  places  we  might  mention. 

Robert  Allen,  Mendota,  111.  Amateur  9CTF. 
133,01 1  miles.  A  Grebe  CR-8  receiver  with  a  three- 
stage  audio  amplifier.  Mr.  Allen  says:  "This  set 
with  one  tube,  no  R.F.,  has  picked  up  KF1  on  a 
three-foot  loop,  and  1  believe  that  this  is  something 
worth  while  trving  to  duplicate.  1  base  the  success  of 
my  outfit  on  the  aerial  that  I  have,  which  is  305  feet 
long  suspended  between  two  trees.  The  ground 
consists  of  three  6-ft.  pipes  driven  in  moist  earth." 

A.  T.  Hull,  Jr.,  318  Armistead  Avenue,  Hampton, 
Va.  123,470  miles.  "Down  by  the  sea  in  Hamp- 
ton, Va.,  radio  has  full  swing.  Coming  home  this 
evening  I  counted  four  aerials  within  100  >ards  of 
my  house."  Single-circuit  outfit,  with  two  stages 
of  audio. 

Theodore  Nelson,  145 1  Thomas  St.,  St.  Paul, 
Minn.  122,320  miles.  Three-circuit,  single-tube, 
with  plate  variometer. 

Alvin  J.  Meyers,  69  New  St.,  Blue  Island,  111. 
1 19,223  miles.    Home-made  three-tube  outfit. 

W.  Hall  Moss,  Dayton,  Tenn.  115,155  miles. 
Three-circuit  set,  home-made. 


NOT  AN   X-RAY   PHOTO,   BUT  A   PLATE  GLASS  PANEL 

The  set  is  the  work  of  G.  O.  Wilkinson  of  Philadelphia,  Pa.  The  "Home-Built"  Coil,  which  he 
manufactures,  is  an  important  part  of  this  set.    One  of  them  is  seen  behind  the  upper  left-hand  dial 


Various  Sorts  and 
Sizes,  All  Home- 
Made 


A  3-TUBE  SET  IN   A  SMALL  SPACE 
It  was  built  hy  William  J.  MacChesney  of  Sum- 
mit, N.  J.    The  switch  between  the  two  dials 
turns  on  and  off  the  filaments,  at  the  same  time 
changing  the  number  of  turns  of  the  primary  coil 


GEORGE  WOODRUFF,  OF  WINCHESTER,  V 
With  the  single-circuit  outfit  he  made 


A  NEAT  JOB,  DON'T  YOU  THINK? 
Another  view  of  Mr.  Wilkinson's  receiver 


49i 


J.  H.  Taylor  (age  13),  1434  Meridian  PI.  N.W., 
Washington,  D.  C.    110,021  miles.  Home-made 
single-circuit  regenerator,  plus  two  stages  of  audio. 
Three-wire  antenna  55  feet  long  and  50  feet  high. 

H.  S.  Fredrickson,  406  Howard  St.,  Charles  City, 
Iowa.  109,500  miles.  170  different  stations,  of 
which  121  were  heard  on  one  tube  (single-circuit). 

Lester  Witherby,  in  care  of  W.  B.  McCIure, 
263  E.  43rd  St.,  Seattle,  Wash.  108,122  miles. 
See  July,  1923,  Radio  Broadcast,  page  236. 

Edward  A.  Block,  1805  Peabody  Ave.,  Dallas, 
Texas.    104,605  miles.    Reinartz  circuit. 

Albert  Hiller,  Jr.,  701  N.  39th  St.,  Philadelphia, 
Pa.  104,230  miles.  Two  radio,  detector,  and  two 
audio,  home-made. 

George  Kingston,  722  First  St.,  Fort  Meyers, 
Fla.  103,180  miles.  A  De  Forest  D-7  reflex  loop 
receiver,  used  with  a  three-foot  loop  and  outdoor 
antenna  and  ground.  During  parts  of  February 
and  March,  Mr.  Kingston  heard  Los  Angeles 
almost  every  night.  One  night  he  pulled  in  four 
stations  on  the  West  Coast. 

Cecil  Newton,  Webster,  N.  Y.  101,665  miles. 
Home-made  single-tube  set.  Says  Mr.  Newton: 
"I  think,  of  all  the  evenings  of  enjoyment  I  ever  had 
the  first  evening  with  my  set  was  the  best.  'Ain't 
it  a  grand  and  glorious  feeling  when  you  have  ac- 
complished soemthing  that  works." 

Thomas  Mahoney,  1900  Crockett  St.,  Dallas, 
Texas.  100,600  miles.  Reinartz  tuner,  home-made 
with  two  stages  of  audio. 

Edward  M.  Starkey,  Le  Sueur,  Minn.  99,675 
miles. 

Fred  R.  Nicholls,  Cle  Elum,  Wash.  107  stations  on 
his  home-made  Reinartz  and  two  audio  equipment. 

L.  W.  Carlisle,  Lisbon,  N.  D.  96,673  miles. 
Aeriola  Sr.  with  one  stage  of  home-made  audio- 
frequency amplification.  He  got  WJZ  (1300  miles 
from  Lisbon)  on  May  5th,  after  trying  all  winter. 

Elmer  Gruneske,  1282  W.  106th  St.,  Cleveland, 
Ohio.  95,485  miles.  Westinghouse  RC  and 
two  steps. 

Joesph  Gretter,  Grandin,  N.  D.  94,387  miles. 
One-tube,  single-circuit  home-made. 

Roscoe  Robinson  (age  14),  Ponca  City,  Okla. 
93,475  miles.  See  page  237,  Radio  Broadcast 
for  July,  1923. 

George  W.  Miller,  Box  293,  Manitou,  Colorado. 
91,420  miles.  Three-circuit  regenerator  with  two 
stages  of  audio.  Mr.  Miller  has  received  voice 
from  coast  to  coast  and  from  the  Gulf  to  the  north 
of  Canada.  He  mentions  that  from  his  home  in 
Colorado  he  has  also  brought  in  code  from  distant 
points  at  sea  and  from  Germany. 

Harold  D.  Smith,  Box  131,  Ducor,  Calif.  90,055 
miles. 

Daniel  Lamb,  229  West  1st  St.,  Mesa,  Ariz. 
88,795  miles.    See  page  238  in  July  issue. 

Edgar  I.  Eisenstadt,  Highland  Park,  111.  87,840 
miles. 


W.  S.  Neely,  Chester,  S.  C.  85,509  miles. 

Alvin  Rasmussen,  Box  503,  Chinook,  Montana. 
85,185  miles. 

A.  J.  Master,  Highgate,  Ontario,  Canada.  84,965 
miles. 

Wm.  J.  MacChesney,  34  Hawthorne  Place, 
Summit,   N.   J.     84,100  miles. 

Henry  Duderstadt,  6041  Main  St.,  Kansas  City, 
Mo.    81,040  miles.    See  page  238  in  July  issue. 

G.  O.  Wilkinson,  417  Walnut  St.,  Phildelaphia, 
Pa.  79,985  miles.  Photos  of  his  set  are  published 
in  this  issue,  page  490.  He  sent  us  a  sample  of  the 
well-made  "Home-Built"  tuning  coil  which  he 
manufactures. 

W.  E.  Dougherty,  Box  44,  Ault,  Colo.  78,405 
miles. 

L.  J.  Love,  Warrensburgh,  N.  Y.     78,015  miles. 

Wesley  Thomas,  Little  Falls,  N.  J.    77,550  miles. 

Lloyd  Saxon,  Box  214,  Clovis,  Calif.  77,324  miles. 

Robert  R.  Taylor,  Prospect  Ave.,  Willow  Grove, 
Pa.  74,505  miles.  He  has  logged  Los  Angeles 
13  times,  San  Francisco  once,  Calgary  once,  and 
Denver  3  times.  Grebe  CR-5  and  Sleeper  two-stage 
amplifier. 

Dwight  V.  Johnson,  Box  242,  Ludington,  Mich. 
71,965  miles  all  on  loud  speaker.  Three-circuit, 
single-tube  twin-variometer  set.  In  tests  aboard 
a  steamer  on  Lake  Michigan,  Mr.  Johnson  brought 
in  KFI  and  KHJ  on  two  successive  nights,  so  loud 
that  their  programs  could  be  heard  all  over  the 
ship's  cabin. 

Curtis  Herbert,  185  Montrose  Ave.,  Rutherford, 
N.  J.  69,501  miles  See  page  238,  July  Radio 
Broadcast. 

Bruce  MacDonald,  1817  E.  3rd  St.,  Duluth, 
Minn.    69,175  miles. 

Stephen  Carleton  Rogers,  21  Red  Rock  St.,  Lynn, 
Mass.    68,755  rniles. 

Jack  Ryder,  1100  Westwood  Ave.,  Columbus, 
Ohio.  67,920  miles. 

Howard  H.  Weston,  Palisade,  Colo.    65,850  miles. 

George  O.  St.  Charles,  408  Lincoln  Avenue, 
Wayne,   Mich.    65,188  miles. 

W.  F.  Delp,  Rural  Retreat,  Va.    63,939  miles. 

Edwin  M.  Nisson,  Radio  9EAM,  2544  Washington 
St.,  Denver,  Colo.  63,780  miles.  See  page  238 
July  Radio  Broadcast. 

Ted  Lehman,  520  W.  Greenup  Ave.,  Ashland, 
Ky.    62,91 5  miles. 

Q.  Scott,  Aurora,  Nebr.    60,903  miles 

R.  P.  Mc  Elhiney,  Madison,  Me.  59,840  miles. 
See  page  238,  July  Radio  Broadcast. 

Leo  M.  Dillev,  Sunfield,  Mich.    59,391  miles. 

Arthur  Weld',  Radio  9DHH,  Cleveland,  N.  D. 
58,795  miles. 

Jonathan  Eldridge,  Jr.  (age  14),  Chatham,  Mass. 
58,585  miles. 

Sten  Anderson,  3247  Q  St.,  Lincoln,  Nebr.  58,480 
miles. 

Rolland  R.  La  Pelle,  Takoma  Park,  Washington, 


492 


Radio  Broadcast 


D.  C.  56,905  miles.  See  page  238,  July  Radio 
Broadcast. 

Wilbur  S.  Nay,  41 5  1 6th  St.,  Manhattan,  Kansas. 
55,931  miles. 

Gerard  Curtiss,  Wauwatosa,  Wis.    54,765  miles. 

Robert  Selby,  1014  Bacon  St.,  Pekin,  111.  52,651 
miles. 

j.  H.  L.  Fincke,  511  Elliott  St.,  Evansville,  Ind. 
52,040  miles.    See  photo,  page  418. 

E.  D.  Harrington,  2331  Blake  St.,  Berkeley, 
Calif.  51,974  miles.  See  page  234,  July  Radio 
Broadcast. 

M.  A.  Jaeger,  Englewood,  Colo.    51,525  miles. 

Sam  Terranella,  1101  Preston  St.,  Dallas,  Texas. 
5 1 ,370  miles. 

Harry  B.  Davenport,  1631  N.  61st  St.,  West 
Philadelphia,  Pa.  50,758  miles. 

H.  Wilbur  Poison,  Geneseo,  111.    50,600  miles. 

Louis  I.  Roland,  U.  S.  Navy  Radio  Station  (NPL), 
Point  Loma,  Calif.    47,800  miles. 

Fred  and  Albert  Yohn,  Norwalk,  Conn.  47,748 
miles. 

William  S.  Best,  in  care  of  Washburn,  Crosby 
Co.,  Minneapolis,  Minn.    47,046  miles. 

A.  W.  Bothwell,  2921  P  St.,  Lincoln,  Nebr. 
44,400  miles. 

James  W.  Brennan,  36  Front  St.,  Beverly,  Mass. 
44,220  miles. 

Don  Ross,  123  Hibbert  St.,  Ironwood,  Mich. 
44,040  miles.  See  photo,  page  238,  July  Radio 
Broadcast. 

Arthur  H.  Phillips,  297  Victor  St.,  Winnipeg, 
Manitoba.    43,825  miles. 

John  D.  Wylie,  Lancaster,  S.  C.  43,517  miles. 
Mr.  Wylie  says:  "  1  am  sure  that  mine  is  no  record, 
but  when  one  considers  that  I  am  too  deaf  to  hear  a 
loud  speaker,  a  conversation,  a  sermon,  the  tick  of  a 
clock  (except  at  PWX  in  Havana,  Cuba),  or  a  tele- 
phone ring,  1  think  it  is  truly  wonderful  that  I- have 
been  able,  alone,  to  tune  in  so  many  stations,  hear  the 
call  letters  and  announcements  clearly,  and  then 
the  programs,  with  a  pair  of  ear  phones,  using  an 
RC  set  consisting  of  a  detector  and  two  stages  of 
amplification.  The  radio  is  a  joy  to  the  deaf.  I 
did  not  realize  before  1  bought  my  radio  that  music 
sounded  so  sweet." 

W.  R.  Bradford,  The  North  American,  Philadelphia, 
Pa.  43,320  miles.  One  of  the  drawings  that  Car- 
toonist Bradford  sent  in  with  his  entry  is  reproduced 
on  page  493. 

Franklin  S.  Bradfield,  Lawrence,  Mich.  43,160 
miles. 

John  H.  Dixon,  Plant  Engineer  at  Station  VMG, 
Apia,  Samoa.  41,225  miles.  This  is  interesting — 
Mr.  Dixon  lists  only  9  stations,  but  none  of  them  is 
under  4290  miles  from  his  receiving  set!  Seven 
of  them  are  California  stations,  and  the  other  two 
are  in  Kansas  City,  5460, and  Davenport,  Iowa,  5735! 
His  letter  left  Samoa  on  April  10th,  before  he  knew 
of  this  receiving  contest.    Explanation  follows: 


Radio  Station 
Apia,  Samoa. 
April  10th,  1923. 

The  Editor, 
Radio  Broadcast, 
Dear  Sir, 

Now  that  your  "How  Far  Have  You  Heard  on  One 
Tube?"  Contest  is  finished,  perhaps  you  will  be  having 
another  for  two  tubes.  To  start  it,  if  so,  I  send  the  follow- 
ing, all  well  over  4200  miles  from  Apia.  To  eliminate  any 
stray  references  to  "fish  yarns"  I  include  proofs  of  recep- 
tion in  every  case.  In  regard  to  the  reception  from  KFI, 
the  speech  comes  in  so  well  that  if  the  announcer  was  to 
speak  slow  enough  to  enable  me  to  write  his  remarks  down, 
I  could  do  so  without  error  at  least  four  nights  a  week  all 
the  year  round.  I'd  do  it  oftener,  but  Old  Man  Static 
lives  here. 

All  these  stations  are  received  on  an  amateur  aerial  swung 
between  two  California  pine  trees.  The  trees  have  been 
imported  and  are  about  the  only  ones  of  their  kind  in 
Samoa.    Perhaps  they  like  music  from  home. 

The  circuit  I  am  using  is  an  adaptation  of  the  supers 
regenerative  using  two  valves.  I  can  get  the  same  results 
with  a  five-valve  receiver  using  three  stages  of  radio- 
frequency  amplification  (tuned  transformer).  Both  sets 
are  home-made. 


COMMENTS  ON  THE  CONTEST 

IT  IS  a  pleasure  to  be  able  to  say,  that  al- 
though no  discrimination  was  made  against 
the  single  circuit  in  judging  the  Receiving  Con- 
test, three-circuit  sets,  or  other  than  single- 
circuit  types,  won  the  contest  "hands  down." 
Although  the  single-circuit  hook-up  is  satisfac- 
tory for  isolated  districts,  we  are,  of  course, 
opposed  to  its  use  in  communities  where  the  re- 
radiation  is  likely  to  disturb  listeners-in.  Of  the 
four  Prize  Winners  and  four  "Honorable  Men- 
tions,"only  two  described  a  single-circuit  outfit. 

What  conclusions  are  we  to  draw  from  the 
fact  that  comparatively  few  people  with  ready- 
made  sets  entered  the  Contest?  It  maybe 
that  many  of  them  thought  the  Contest  was 
open  only  to  those  with  home-made  apparatus, 
in  spite  of  our  announcement,  "any  kind  of  a 
receiver  .  .  .  any  number  of  tubes."  An- 
other explanation,  and  one  that  seems  logical, 
is  that  the  purchaser  of  a  ready-made  set  is 
generally  interested  primarily  in  the  entertain- 
ment rather  than  the  experimental  phase  of 
broadcasting;  while  the  builder  of  a  set  is  often 
"out  after  distance,"  and  learns  more  about 
fine  tuning  than  the  owner  of  a  bought  set. 

Be  all  this  as  it  may,  the  "turn-out"  in  the 
contest  was  mighty  good.  We  congratulate 
those  contestants  whose  articles  have  been 
printed  in  these  pages,  and  to  all  the  others 
who  sent  in  articles,  photos,  and  hook-ups  we 
wish  to  express  our  admiration  of  the  fine  work 
which  they  have  done  and  our  thanks  for  the 
reports  which  they  submitted. 


THIS  AMATEUR  HEARS  LONDON  REGULARLY 
But  this  is  scarcely  strange  because — he  lives  there.  Frederic  L.  Hogg,  Radio 
2SH,  of  Highgate,  London,  numbers  the  following  stations  among  his  American 
acquaintances:  WJZ,  WGI,  WGY,  WOO,  WOR,  WEAF,  and  WDAF  (Kansas 
City)!  About  60  amateurs  in  the  United  States  have  also  been  heard,  includ- 
ing 5ZA  in  New  Mexico.  Mr.  Hogg  says  that  his  10-Watt  transmitter  has 
been  heard  all  over  Europe 


Some 
Pictures 

the 
Contest 
Brought 
In 


These  Were  Picked  from 
Among  Several  Hundred, 
to  Illustrate  Various 
Phases  of  the  Broadcast- 
ing Game.  Home-Made 
Equipment  Predomi- 
nated 


HYAH!  ain't  you 

GONA  STAY  AN' 
USTEN  TO  KSD? 


N  AW.  in  GONA  JJO 
A  little  broadcasts 
Muhself! 


CARTOONIST  BRADFORD  SENT  US  THIS 
When  not  drawing  for  the  Philadelphia 
North  American,  he  experiments  with 
receiving  sets  which  he  builds  himself 


MR.  J.  H.   L.   FINKE  AND  SON  BOB 

Of  Evansville,  Indiana.  With  this  one-tube  of 
theirs,  they  have  heard  Los  Angeles  in  a  pouring  rain 


THE  BETTER  THE  GROUND,  THE  BETTER 
THE  SOUND 
Bruce  MacDonald,  of  Duluth,  Minn.,  shows 
how  heavy  wire,  a  standard  ground  clamp, 
and  a  well-scraped  pipe  are  "all  there  is  to  it" 


THE  CAPITAL  CITY  VIEWED  FROM  ONE  OF  THE  CROSS-ARMS  AT  WRC 


A  New  Station  at  Washington,  D.  C. 

A  Description  of  WRC  and  its  Meaning  to  the  Capital 
By  PIERRE  BOUCHERON 


ON  AUGUST  i  st  there  was  dedi- 
cated to  the  American  public  at 
Washington,  D.  C.  another  link 
of  the  great  chain  of  broadcasting 
stations  of  the  Radio  Corporation 
of  America.  WRC  has  fittingly  enough  been 
named  by  its  sponsors  "The  Voice  of  the  Capi- 
tal." To  every  corner  of  the  United  States, 
this  powerful  station  may  carry  the  words  of 
great  men  in  political  and  diplomatic  life,  the 
progress  of  world  events  as  they  transpire,  and 
the  music  of  our  nation  as  well  as  of  other 
nations  rendered  by  visiting  musicians.  This 
station  provides  an  instantaneous  link  between 
the  country's  political  centre  and  the  Ameri- 
can home.  A  better  understanding  of  govern- 
ment, of  the  issues  involved  in  political  cam- 
paigns, and  of  the  questions  which  arise  in  our 
relations  with  foreign  countries,  cannot  fail  to 
result  from  its  operation. 


There  is  a  wealth  of  material  available  in 
Washington  from  which  to  make  the  programs 
of  WRC  most  enjoyable  and  educational.  At 
once  it  is  possible  that  the  ceremonies  accom- 
panying the  dedication  of  memorials  to  great 
Americans,  the  features  of  the  many  conven- 
tions held  in  this  city,  and  the  spiritual  counsel 
of  the  clergy  may  be  carried  to  the  transmitter 
and  sent  forth  so  that  the  whole  country  may 
hear  and  appreciate  them. 

Momentous  events,  of  interest  to  the  nation, 
do  not,  of  course,  occur  every  day.  The 
greater  part  of  this  station's  operating  hours 
will  be  devoted  to  the  broadcasting  of  the 
musical  and  dramatic  talent  of  Washington  and 
other  events  of  special  interest  to  residents  of 
this  city.  Washington  is  rich  in  both  profes- 
sional and  amateur  talent  and  every  effort  will 
be  made  by  those  in  charge  to  arrange  programs 
so  that  these  local  interpreters  of  music  and 


A  New  Station  at  Washington,  D.  C. 


495 


drama  may  be  heard  from 
time  to  time. 

LOCATION  IDEAL  FOR  RADIO 

THE  Riggs  National 
Bank  Building,  inwhich 
both  studio  and  equipment 
are  accommodated,  is  one  of 
the  highest  points  in  the 
city,  with  no  tall  steel  struc- 
tures near  by  to  absorb  and 
influence  the  waves  radiated 
from  the  station.  The  office, 
studio,  and  equipment  are 
all  on  the  second  floor  of 
the  building.  Within  the 
studio,  which  is  one  of  the 
largest  used  in  America  for 
broadcasting  work,  all  is 
harmonious,  dignified,  and 
restful.  The  panelled  walls 
are  done  in  old  ivory  and 
brown  while  the  windows 
are  draped  with  heavy 
hangings  of  maroon.  A 
feature  of  the  walls,  which 
is  not  apparent  while  look- 
ing at  them,  is  discovered 
when  one  touches  the  panels. 
The  lightest  pressure  of  the 
finger  will  bend  them  out- 
ward. These  walls  play  an 
important  role  in  broadcast 
transmission.  They  are 
made  of  wax-treated  muslin 
laid  over  felt  and  absorb 
all  sound  waves  not  entering 
the  microphone.  This  acoustically  correct 
construction  prevents  even  the  minutest  echo 
which  might  otherwise  blur  the  clearness 
necessary  to  enjoyable  entertainment. 


rHE  AERIAL  WIRES  ARE  I  50  FEET  ABOVE  THE  STREET  LEVEL 

And  there  is  nothing  in  the  vicinity  of  the  Riggs  Bank  Build- 
ing which  can  obstruct  the  radiation  of  waves  from  this  station 


light, 


SEEING    THE  BROADCASTED  VOICE 

ALL  THE  experience  and  recent  improve- 
.  ments  which  are  part  of  the  Broadcast 
Central,  the  Radio  Corporation's  duplex  station 
in  New  York,  are  embodied  in  Station  WRC. 

An  important  feature  of  this  station,  and 
one  which  further  assures  perfect  trans- 
mission of  programs,  is  the  device  known 
as  the  oscillograph,  by  which  the  operators  have 
before  them  "a  working  picture  of  the  voice." 
This  delicate  instrument  may  be  switched  into 
any  one  of  the  many  circuits,  and  shows,  by 
means  of  an  undulating,  ever-varying  beam  of 


is  affecting 


voice  or  music 
By  watching 
reflected  from 


exactly  how  the  artist's 
the  radio  current, 
this  little  tell-tale  beam,  as 
revolving  mirrors,  one  knows  instantly  whether 
the  sound  waves  are  too  weak,  too  great  in 
volume,  or  blurred. 

Broadcasting  is  a  living,  vibrant  force  that 
has  as  its  chief  aim  the  improvement,  both 
spiritual  and  intellectual,  of  mankind.  When 
conducted  on  such  a  high  plane  as  this,  WRC 
cannot  but  thrill  the  distant  listener  with  a 
constantly  varying  entertainment  that  falls 
little  short  of  magic.  It  is  the  hope  of  those 
who  conceived  and  built  this  great  broadcast- 
ing plant  that  "The  Voice  of  the  Capital"  will 
always  entertain  and  instruct  only  with  what 
is  for  the  good  and  the  advancement  of  the 
thousands  who  will  nightly  tune-in  its  message. 


Rheostats  for  the  Tubes  You  Use 


How  to  Select  the  Proper  Rheostat.  Operating  Different  Kinds  of 
Tubes  From  the  Same  Battery.    Using  Tubes  in  Series  and  in  Parallel. 

By  ZEH  BOUCK 


THE  advent  of  the  dry-cell  tube,  while 
making  radio  a  more  simple  and 
economical  proposition,  has  by 
chance  complicated  matters  when 
enthusiasts  have  attempted  to  oper- 
ate such  tubes  from  voltages  other  than  those 
for  which  they  have  been  designed — a  possi- 
bility that  is  often  made  desirable  by  the  posses- 
sion of  a  six-volt  storage  battery.  Similar 
difficulties  are  encountered  when  it  is  en- 
deavored to  light  different  makes  of  dry-cell 
tubes,  with  their  individual  filament  require- 
ments, from  the  same  battery,  and  haphazard 
experiments  by  many  fans  have  resulted  in 
blown  tubes.  Such  disasters,  however,  would 
have  been  obviated  by  an  understanding  of 
perhaps  the  most  fundamental  of  electrical 
axioms,  Ohm's  law,  and  its  application  in 
solving  the  problems  of  the  proper  battery  and 
rheostats. 

Ohm's  law  is  a  statement  of  the  three  pre- 
dominant characteristics  of  an  electrical  cir- 
cuit, the  voltage,  current,  and  resistance,  and 
the  limitations  imposed  by  any  two  of  these 
qualities  upon  the  remaining  one,  i.  e.,  their 
inter-relation. 

In  the  pioneer  days  of  electricity,  helped 
along  by  the  fluid  theory  of  electric  currents 
that  then  prevailed,  physicists  were  led  by 
observations  to  the  correct  conclusion  that  elec- 
trical phenomena  possessed  two  characteristics, 
voltage  and  current,  the  former  being  the 
pressure  that  sent  the  current  through  the 
wire,  and  the  current  itself  being  the  density 
or  heaviness  of  the  electrical  stream.  It  was 
found  that  this  last  quality,  current,  depended 
on  two  things,  first  upon  the  voltage  or  pressure 
and  secondly,  upon  the  resistance  of  the  con- 
ductor or  wire.  As  the  pressure  increased,  it 
was  quite  natural  that  the  current  would  be- 
come heavier;  as  would  a  lazy  stream  of  water  in 
a  pipe  when  the  force  applied  to  the  reservoir 
end  was  multiplied.  It  also  followed,  that  as 
the  resistance  of  the  conductor  was  made 
greater,  for  instance  by  using  a  smaller  wire,  the 
current  was  decreased,  as  would  be  the  flow  of 


water  in  the  aforementioned  pipe  were  a 
plumber  to  substitute  a  smaller  diameter  pipe 
or  place  some  obstruction  (resistance)  within, 
it.  This  law  of  electric  currents  is  expressed  in 
the  equation, 

E 
~R 

I,  E,  and  R  mean,  respectively,  current  in 
amperes,  potential  or  pressure  in  volts,  and  re- 
sistance in  ohms.  Hence  we  might  substitute 
for  the  abbreviations  or  symbols,  and  state  the 
equation, 

potential 
current  =   


or,  still  another  way, 


amperes  ■ 


resistance 


volts 


ohms 


By  obvious  algebraic  transpositions,  the  two 
following  equations  are  simply  derived  from  the 


original  statement: 


R=  —  for  finding  resistance 
1 

and 

E  =  I  x  R  for  finding  voltage  or  "voltage  drop." 

These  equations  are  of  inestimable  value  in 
all  electrical  work,  and  are  particularly  applic- 
able, as  will  be  shown,  to  the  calculation  of 
filament  resistances  and  voltages. 

WHAT  SIZE  RHEOSTAT  SHALL  I  USE? 

THE  accompanying  chart,  Fig.  i,  shows  the 
three  laws,  and  indicates  the  various  com- 
putations in  which  they  are  commonly  involved. 
The  equation  most  readily  applicable  to  the 
operation  of  the  dry-cell  tube  is  the  second,  and 
which  declares  that  the  resistance  is  equal  to 
the  voltage  divided  by  the  current. 

We  shall  presume  that  the  reader  is  interested 
in  the  construction  of  a  portable  set  with  de- 
tector and  one  step,  using  the  UV-199  tubes. 
Referring  to  Fig.  2  (or  to  the  circular  accom- 
panying the  UV-199  when  it  is  bought),  it  will 


Rheostats  for  the  Tubes  You  Use 


497 


resistance 


be  found  that  this  tube  con- 
sumes .06  ampere  at  its  nor- 
mal filament  potential  of 
three  volts.  Three  volts  are 
the  equivalent  of  two  dry 
cells,  but  as  the  voltage 
of  such  a  battery  drops 
quickly,  three  cells  should 
be  used,  in  which  case  the 
deterioration  can  be  com- 
pensated for  by  lowering 
the  rheostat.  We  now  en- 
counter the  problem,  "Us- 
ing these  three  dry  cells, 
what  size  rheostat  shall  I 
get?  Will  not  the  six-  or 
ten-ohm  size  be  too  low?" 
Or,  more  technically,  it  is 
desired  to  determine  what 
resistance  is  required  to 
drop  the  potential  of  the 
battery  to  three  volts,  or 
in  terms  of  the  second 
formula,  what  total  resistance  in  series  with  the 
4!  volt  battery  (three  dry  cells)  will  permit  but 
.06  ampere  to  traverse  the  circuit. 

To  find  this  out,  it  is  merely  necessary  to 
substitute  the  known  quantities,  volts  (4^)  and 
amperes  (.06)  for  the  corresponding  letters  in 
the  second  equation,  i.e.,  R  =  .%$  thus  R  =  75, 
or  seventy-five  ohms  must  be  the  resistance  of 
the  entire  circuit.  But,  again  referring  to 
Fig.  2,  it  will  be  found  that  the  resistance  of  the 
UV-199  filament  is  fifty  ohms,  which  is  neces- 
sarily included  in  the  circuit,  and  forms  the 
greater  part  of  the  seventy-five  ohms  resistance. 
Hence  the  extra  resistance,  or  rheostat,  need 
be  only  25  ohms.  (This  is  the  extra  resistance 
necessary  to  drop  the  4!  volts  to  3  volts,  the 
working  potential  of  the  tube.  That  this  is 
so  will  be  proved  by  substituting  in  equation 
three:  E  =  25  x. 06  =1.5 — i.e.,  the  voltage  drop 
is  1.5,  which  subtracted  from  4!  volts  gives  the 
required  3  volts!) 

To  find  the  resistance  for  any  rheostat,  substi- 
tute, in  equation  number  two,  the  voltage  of  the 
battery  and  the  current  of  the  tube.  From  this 
answer,  which  is  the  total  resistance  of  the  circuit, 
subtract  the  resistance  of  the  filament.  (It  is 
always  desirable  to  add  a  few  ohms  to  the  re- 
sult of  this  calculation  in  order  to  take  full  ad- 
vantage of  low  filament  consumption.  Thus  a 
30-ohm  rather  than  a  25-ohm  rheostat  is  sug- 
gested for  the  UV-199.) 

If  the  filament  resistance  is  neither  known 


■  ____ 

Q  HWy6      L  A  W 


z.  ~R< 


Li/       .  .v.  i  „  Ji  tfta  kfe.  /       •     ''  :„  -    k»  ■*  . 


'•"/•  #—SlU&6  fitf*  Wi  CfS.,  <t\  ItJ&L  .  ! 


-  P    T  ^  Oh  dJbr^H-^  Si.  A^^k^itt^  i 


FIG.  I 

Three  ways  of  expressing  the  inter-relation  of  voltage,  current,  and 
They  help  you  select  the  proper  rheostats  for  your  tubes 


nor  covered  in  the  Radio  Broadcast  chart,  it 
is  easily  calculated  from  the  voltage  and  am- 
perage furnished  by  the  manufacturer  of  the 
tube,  by  means  of  this  same  equation  two. 
Substituting  these  values  in  the  case  of  the 
UV-199  just  discussed,  our  equation  is  R  =  .o:V 
=  50  ohms. 

DIFFERENT   TUBES    WITH    THE    SAME  BATTERY 

I T  IS  quite  possible  that  the  owner  of  the  port- 
1  able  set  mentioned  above  will  desire  to  sub- 
stitute a  WD-i  1  or  WD-12  (i|  volts,  J  ampere) 
for  the  UV-199  as  detector.  If  the  A  battery  is 
made  up  of  three  standard  dry  cells,  a  single 
one  of  these  may  be  used  to  light  the  detector 
filament,  obviating  the  necessity  for  any  calcu- 
lations. However,  if  a  three-cell  flashlight 
battery  is  employed,  as  is  the  probability,  it 
will  be  easier  to  resort  to  resistance  than  to 
break  through  the  insulating  compound  and 
tap  the  battery.  Due  to  the  different  direct- 
current  characteristics  of  this  tube,  it  is  quite 
obvious  that  its  rheostat  requirements  will 
differ  from  those  of  the  UV-199.  (However, 
as  the  WD- 1 1  does  not  require  so  high  a  resis- 
tance, as  will  be  shown,  it  would  not  be  posi- 
tively necessary  to  change  the  rheostat.)  The 
value  of  this  rheostat  is  obtained  by  again 
substituting  in  the  second  formula,  viz.,  R  = 
.%f  =18  ohms.  Subtracting  from  this  the  re- 
sistance of  the  WD-11  filament,  and  adding 
a  few  ohms  for  safety  and  adjustment,  the 


498 


Radio  Broadcast 


desirable  rheostat  will  have  a  resistance  of 
1 5  ohms. 

IS  iMY  RHEOSTAT  LARGE  ENOUGH? 

ANOTHER  problem  which  quite  frequently 
l  confronts  the  experimenter  running  the 
eternal  gamut  of  circuits  and  tubes,  is  the  ques- 
tion as  to  whether  a  rheostat  which  adequately 
controlled  a  previous  tube,  possesses  a  resis- 
tance sufficiently  high  to  safeguard  the  audion 
in  his  new  experiment.  This  can,  of  course, 
be  solved  in  a  round-about  fashion  by  the  R  =^ 
formula,  but  by  the  .third  equation, 
E  =  1  x  R,  it  admits  of  an  easier  solu- 
tion, and  it  is  only  necessary  to  know 
the  current  consumption  of  the  tube 
and  the  resistance  of  the  rheostat. 

We  shall  assume  that  the  experi- 
menter has  been  using  in  his  ampli- 
fier  Western    Electric   VT-2's,  the 

5 -  watt  transmitting  tubes.  He  has  lighted 
these  from  an  8-volt  storage  battery  through 

6-  ohm  rheostats.  Without  changing  his 
battery  or  other  equipment,  he  now  desires 
to  substitute  for  these  uneconomical  bulbs  the 
201-A,  a  6-volt,  j-ampere  tube.  Will  the  6- 
ohm  rheostats  be  sufficient?  .  .  .  will  they 
give  a  2-volt  drop  (8  to  6)? 

E  =  1  x  R 
E  =  .25  x  6 

E  =  1 .5  (the  voltage  drop) 
No!    A  larger  rheostat  will  be  necessary. 
To  determine  if  a  certain  rheostat  is  sufficient 
to  drop  a  high  voltage  to  a  recjuired  lower  potential, 
substitute  for  I  and  R  in  formula  three.  The 
answer  will  be  the  voltage  drop. 


M 


TUBES  IN  PARALLEL 

ANY  enthusiasts  have  endeavored  to 
operate  dry-cell  tubes  and  others  in 
parallel  from  a  single  rheostat,  the  voltage  drop- 
ping function  of  which  was  augmented  by  the 
increase  in  current  passing  through  it.  It  will 
be  observed  from  study  of  the  last  formula,  that 
E,  or  the  voltage  drop,  depends  directly  upon 
the  amperage.  If  the  current  through  a 
rheostat  is  raised,  the  voltage  drop  will  be  in- 
creased in  proportion.  For  instance,  if  the 
experimenter  is  desirous  of  working  a  two-bulb 
set  using  UV-190/s,  from  a  6-volt  storage  bat- 
tery through  individual  rheostats,  he  will  find 
by  calculations  in  formula  two,  which  we  have 
described,  that  he  will  require  rheostats  of  50- 
ohms  resistance  each.  However,  if  he  connects 
the  filaments  of  the  two  tubes  in  parallel, 


lighting  them  through  a  single  rheostat,  only 
a  25-ohm  rheostat  will  be  required.  (This  fact 
will  also  be  furnished  by  formula  two,  if  it  is 
remembered  that  the  current  is  now  doubled.) 
In  terms  of  the  third  formula,  this  condition  is 
as  follows: 

E  =  25  (R  in  ohms)  x  .12  (current  of  two  .06 
ampere  tubes).    Carrying  it  out,  E  =  3. 

Hence  the  voltage  drop  is  three,  which  sub- 
tracted from  six  leaves  3,  the  correct  voltage 
for  the  UV-199. 

A  single  rheostat  of  25  ohms  is  much  easier  to 
obtain  than  two  50-ohm  instruments. 
However,  the  writer  does  not  approve 
of  nor  recommend  this  apparent  econ- 
omy. On  the  contrary  he  advises 
strongly  against  it  for  the  very  reasons 
(Ohm's  law  number  three)  outlined 
above  and  which,  at  first  sight,  appear 
to  favor  this  system.  A  little  thought 
will  indicate  the  disaster  which  would,  in  such  a 
circuit,  accompany  the  failure  of  one  of  the 
tubes  to  light,  either  from  socket  or  connection 
trouble,  or  burning  out.  Such  a  failure  would 
lessen  the  current  through  the  single  rheostat 
and  correspondingly  curtail  the  voltage  drop, 
and  a  disastrously  high  potential  would  be 
applied  to  the  remaining  tube. 

To  demonstrate  mathematically  (the  reader 
cannot  become  over  familiar  with  the  algebra  of 
Ohm's  law):  It  was  found  that  on  two  bulbs  a 
25-ohm  rheostat  was  sufficient  to  drop  the  six 
volts  to  the  required  three  volts.  However, 
supposing  that  one  tube  ceases  to  function  due 
to  filament  trouble,  we  shall  find  that  the 
voltage  drop,  E  =  l  x  R  =  .o6  x  25  =  1!  volts. 
This  would  leave  4^  volts  on  the  tube,  sufficient 
to  burn  it  out  in  a  few  seconds. 

TUBES  IN  SERIES 

THE  alternative  for  using  one  rheostat  with 
a  plurality  of  tubes  is  connecting  them  in 
series,  but  this  practice,  while  free  from  the 
hazards  of  the  parallel  system,  multiplies  the 
voltage,  practically  by  the  number  of  tubes. 
However,  this  system  has  been  successfully 
used  and  is  quite  justified  with  amplifying  tubes 
which  number  in  radio-frequency  circuits  three 
and  more  (including  audio),  and  where  the 
higher  voltage  has  been  at  hand  or  easily  built 
up.  The.  required  battery  for  such  a  connec- 
tion is  simply  determined  by  formula  three. 
(It  should  be  borne  in  rr.ind  that  the  answer 
given  in  this  equation  is  the  voltage  drop  in 
passing  through  the  mentioned  resistance.  If 


Rheostats  for  the  Tubes  You  Use 


499 


all  the  resistance  in  the  circuit  is  substituted  for 
R,  the  voltage  drop  will  be  the  total  applied 
potential,  or  the  required  voltage  for  the  opera- 
tion of  the  circuit  under  the  stated  conditions  of 
amperage  and  resistance.  Thus,  in  the  case  of 
the  199,  where  the  filament  has  a  resistance  of 
50  ohms,  and  for  normal  operation  consumes 
a  current  of  .06  ampere,  the  voltage  will 
equal  E  =  I  x  R  = 
.06  x  50  =  3  volts) . 

If  it  is  desired  to 
use  four  UV-199's  (to 
continue  with  this 
popular  bulb)  in  series 
and  with  a  single  10- 
ohm  rheostat,  the  fol- 
lowing calculation  is 
carried  out: 

First,  R  must  equal 
the  total  resistance  of 
the  circuit,  i.e.,  the  re- 
sistance of  all  the 
filaments  plus  the  re- 
sistance of  the  rheo- 
stat. (The  resistance 
of  the  battery  and  wir- 
ing is  negligible  and 
merely  adds  a  factor 
of  safety.) 

Second,  I  is  the  cur- 
rent of  one  tube,  for 
the  same  current  flows 
through  all  tubes  and 
is  not  divided  or  split 
as  is  the  case  when 
passing  through  fila- 
ments in  multiple. 

Then  R  will  be: 
10  +  50  +  50  +  50  + 

50  =  210,  and  I  will  be:  .06,  and  the  equation, 
E  =  .o6  x  210=  12.6  or  roughly  eight  dry  cells 
(12  volts). 

To  find  the  required  resistance  for  the  operation 
of  a  series  of  tubes  with  a  given  rheostat,  substi- 
tute the  total  resistance  of  the  circuit  and  the 
amperage  of  one  tube  in  formula  three.  If  a  frac- 
tion results,  use  the  first  whole  number  below 
it — the  rheostat  can  always  be  turned  up. 

When  the  occasion  arises  for  a  calculation 
involving  a  single  resistance  controlling  more 
than  one  tube,  remember  that  filaments  in 


fig.  2 


If  you  know  any  two  of  th 
characteristics — voltage  (E) 
ance  in  ohms  (R) — you  can  fin 
given  in 


series  multiply  the  filament  resistance  of  one 
tube  by  the  number  of  bulbs,  and  filaments  in 
parallel  divide  it  by  the  number  of  bulbs. 

CONCLUSION 

THE  first  Ohm's  law  or  equation  finds  but 
little  application  to  the  subject  discussed. 
The  correct  value  for  I  is  almost  always  known; 

it  is  determined  by  the 
designer  of  the  tube, 
not  by  the  chance 
values  of  E  and  R,; 
and  the  two  derived 
equations  will  solve 
in  a  more  satisfac- 
tory way  whatever 
filament  questions  the 
reader  may  refer  to 
Ohm's  law. 

It  will  be  observed 
that  the  writer,  in 
discussing  dry-cell 
tubes,  has  not  con- 
fined himself  to  their 
operation  from  such 
a  battery,  but  has 
even  suggested  their 
use  from  the  storage 
type.  The  low-amper- 
age  tube  has  not 
merely  made  possible 
the  elimination  of  the 
storage  battery  in 
certain  justifiable 
cases,   but    has  also 

e  three  predominant  tube  added  greatly  to  the 
amperage  (I),  and  resist- 


d  the  third  by  the  formulas 
Fie.  1 


utility  of  that  bat- 
tery. The  storage 
battery  possesses  cer- 
tain desirable  qualities  which  are  missing  in 
dry  cells,  and  in  view  of  the  slow  discharge 
when  used  with  dry-cell  tubes,  they  deserve 
serious  consideration  as  the  filament  source 
in  all  but  portable  sets. 

In  conclusion,  the  writer  desires  to  emphasize 
that  Ohm's  law  is  not  confined  in  its  audion 
applications  to  any  particular  class  of  tubes,  or 
voltages.  It  may  be  used  in  filament  calcula- 
tions involving  32-volt  farm  lighting  plants, 
no-volt  D.  C.  system,  and  with  any  tubes 
whatever. 


THE  CREW  OF  THE   '  BOWDOIN,      ROUNDED  UP  TO  LOOK  PLEASANT 

Left  to  right:  Donald  H.  Mix  (radio  operator),  Tom  McCue  (mate),  Richard  Goddard  (from  the  Carnegie 
Institute  in  Washington),  Captain  MacMillan,  Jaynes  (engineer),  and  Ralph  Robinson  (ship's  doctor 

and  official  photographer) 

With  MacMillan  and  Radio, 
North  of  Civilization 

Adventures  on  the  First  Part  of  the  Arctic  Expedition,  as  Related  by  Mr.  McDonald, 
Who  Went  with  the  Bowdoin  as  Far  as  Battle  Harbor,  Labrador.  How  the  People  in 
the  North  React  to  Radio,  and  What  the  Crew  and  Captain  MacMillan  Think  of  it 

By  e.  f.  Mcdonald,  jr. 


JOHN  Bunyan  was  a  pious  man  and  had 
lots  to  say  about  Sloughs  of  Despond  and 
Giants  Despair,  but  what  a  pity  his  well- 
known  Pilgrim — ever  on  the  watch  for 
stepping-stones  to  progress — should  have 
overlooked  the  rocks  of  Labrador  and  the 
well-trapped  shores  of  Greenland.  For  there  are 
regions  for  you  with  their  very  names  all  made 
to  order  for  an  allegory! 

Think,  for  example,  of  the  adventures  that 
valiant  fighter  might  have  had  while  skirting 
'Anxiety  Point"  and  "Escape  Reef"  and 
"Cape  Hold  with  Hope,"  while  dodging  through 
"Frozen  Strait"  and    "Cut-Throat  Tickle," 


while  sailing  up  "False  River"  and  back,  while 
circling  "Ragged  Island"  or  "Deadman's 
Cove"  or  "Devil's  Bay";  and  how  great  his 
triumph  might  have  been  when  he  finally 
sighted  the  "Isle  of  God  and  Mercy"  and 
brought  his  errant  craft  around  "Cape  Com- 
fort" through  "Hopewell  Narrows"  and  into 
"Refuge  Cove!' 

On  such  a  voyage,  on  the  twenty-third  of 
June,  sailed  forth  the  staunch  ship  Bowdoin, 
captained  by  Donald  B.  MacMillan,  the  noted 
Arctic  explorer,  and  carrying  in  its  forecastle  a 
radio  transmitting  and  receiving  set — the  first 
of  these  sets  to  venture  into  the  land  of  per- 


i 


With  MacMillan  and  Radio,  North  of  Civilization 


501 


petual  ice  and  snow.  Cap- 
tain MacMillan  was  ac- 
companied by  a  cook  (a 
tremendously  necessary 
person),  several  scientists, 
his  friend,  Sheldon  Fair- 
banks, and  myself.  I  left 
the  party  at  Battle  Har- 
bor, Labrador. 

THE  DEPARTURE  FROM 
WISCASSET,  MAINE 

IT  WAS  a  brilliant  scene 
at  Wiscasset,  Maine, 
when  the  Bowdoin — decks 
piled  high  with  supplies  and 
provisions,  and  masts  strung 
with  flags  of  the  interna- 
tional code — set  sail  for  the 
Arctic.  All  the  people  of 
the  countryside  turned  out 
to  bid  the  crew  Godspeed. 
Whistles  blew  and  cannon 
boomed 

On  board  the  ship  for 
the  first  short  stage  of  the 
journey  (to  Boothbay)  were  General  A.  W. 
Greely,  oldest  living  Arctic  explorer,  and 
Langdon  Gibson,  who  accompanied  Comman- 
der Peary  on  his  earlier  Arctic  expeditions.  On 
shore,  and  in  communication  with  the  ship  by 
radio,  were  Hiram  Percy  Maxim,  the  distin- 
guished inventor,  and  Messrs.  K.  B.  Warner 
and  Fred  Schnell,  associated  with  Mr.  Maxim 
in  the  American  Radio  Relay  League,  of  which 
he  is  President.  These  last-named  gentlemen 
had  temporarily  set  up  on  the  dock  a  Zenith 
receiving  set,  and  for  the  first  five  miles  or  more 
they  used  it  to  receive  and  transmit  messages. 
To  accomplish  this  latter  purpose,  they  set  the 
secondary  tuning  on  the  wavelength  that  the 
Bowdoin  was  operating  on,  threw  the  tickler 
into  the  extreme  oscillating  position,  and  by 
touching  the  primary  circuit  with  a  moistened 
finger  sent  back  their  replies  in  international 
Morse  code. 

Donald  H.  Mix,  radio  operator  aboard  the 
Bowdoin,  was  furnished  to  the  expedition  by 
The  American  Radio  Relay  League,  at  the 
League's  expense.  He  was  chosen  from  among 
a  great  number  of  applicants  for  the  coveted 
position.  Long  coded  news  stories  are  being 
received  from  the  Bowdoin  (station  WNP) 
every  week  by  various  member-stations  of  the 
A.  R.  R.  L.,  which  expect  to  keep  in  communi- 


OFFICIALS  OF  THE  A.  R.  R.  L.  AT  WISCASSET,  MAINE 

On  the  right  is  Hiram  Percy  Maxim,  President  of  the  American  Radio  Relay  League, 
the  organization  which  is  sending  operator  Mix  with  the  MacMillan  expedition;  at 
the  left  is  F.  H.  Schnell,  Traffic  Manager  of  the  A.  R.  R.  L.;  and  behind  the  receiv- 
ing set  is  K.  B.  Warner,  Secretary  of  the  League  and  Editor  of  Q  S  J .  The  picture 
was  taken  at  Wiscasset  harbor,  just  before  the  Bowdoin  sailed,  and  the  set  was  used 
in  testing  with  WNP  during  the  first  few  miles  of  her  long  journey 


cation  throughout  the  winter,  when  the  expedi- 
tion will  be  at  its  farthest  north,  some  600  miles 
from  the  Pole. 

From  Monhegan  Island  we  put  to  sea  in 
earnest,  and  within  the  very  first  hour  ran 
into  an  enormous  school  of  blackfish.  These 
are  a  species  of  whale,  and  some  of  them 
ranged  a  full  forty  feet  in  length.  They 
were  sunning  themselves  on  the  surface  of  the 
water,  and  so  complacently  did  they  regard 
us  that  we  were  able  to  approach  within  close 
hailing  distance — so  close,  in  fact,  that  Tom 
McCue  got  a  rise  out  of  one  of  them  by  heaving 
a  can  of  pemmican  against  his  tough  black  hide. 

Clouds  of  fog  enveloped  us  practically  all 
the  way  from  Monhegan  to  Sydney,  Nova 
Scotia.  Notwithstanding  the  impenetrable 
mist,  however,  we  crossed  the  Bay  of  Fundy 
and  rounded  Cape  Sable  without  mishap,  and 
except  for  the  glimpse  of  a  mysterious  ship 
during  one  of  the  night  watches — which  on  our 
approach  extinguished  all  her  lights — we  made 
our  port  without  adventure.  Not  knowing 
whether  the  ship  in  question  was  a  rum  runner 
or  a  rum-runner  chaser,  we  made  no  attempt  to 
overhaul  her. 

From  the  moment  the  last  visitor  stepped 
off  the  gang  plank  at  Boothbay,  strict  discipline 
was  in  force  on  board  the  Bowdoin.    The  day 


was  divided  into  four  watches:  six  hours  on  and 
six  hours  off,  with  one  man  at  the  wheel  and  two 
on  lookout.  We  had  breakfast  at  six,  dinner 
at  noon,  supper  at  six,  and  a  "mug-up"  at 
midnight. 

THE   "BOWDOIN"  AND  WHAT'S   ABOARD  HER 

"  I  HERE  is  not  much  room  to  spare  on  the 
1  Bowdoin — as  you  can  imagine  when  I  tell 
you  all  that  she  carries.  Not  only  is  every 
available  inch  of  space  below  decks  used,  but 
the  main  deck  is  crowded  with  barrels  of  fuel 
and  lubricating  oil,  and  miscellaneous  provi- 
sions of  an  imperishable  nature.  The  Bowdoin 
is  only  eighty-nine  feet  over  all — the  smallest 
ship  that  ever  ventured  an  Arctic  expedition — 
yet  into  her  hold,  amidships,  have  been  packed 
not  only  provisions  and  supplies  sufficient  to 
sustain  the  party  for  several  years,  but  also 
quantities  of  dolls,  clothing,  knickknacks,  and 
phonographs,  these  latter  to  be  presented  to  the 
Eskimos  of  the  most  northerly  tribes.  It  was 
with  difficulty  that  the  hatch  was  battened 
down ! 

Back  of  the  hold  is  the  engine  room,  a  solid 


mass  of  machinery.  Its  four  walls  are  enor- 
mous fuel  tanks  of  kerosene,  which  give  this 
ship  the  greatest  cruising  range  of  any  small 
ship  in  the  world.  This  enormous  fuel  supply 
is  needed  when  one  considers  that  for  many 
days,  with  the  engine  running  full  speed,  the 
ship,  which  normally  makes  nine  knots  an  hour, 
makes  less  than  nine  knots  a  day  against  the 
heavy  ice  jams  of  the  Arctic.  In  the  forward 
end  of  the  engine  room  are  two  f  KW  Delco 
generators  and  two  complete  sets  of  32- 
volt  storage  batteries.  At  present,  one  genera- 
tor and  set  of  batteries  are  being  used  to  light 
the  ship.  The  other  generator  and  batteries 
are  for  the  radio,  which  consumes  a  great  deal  of 
power  in  hurling  its  wireless  messages  back  to 
civilization. 

Back  of  the  engine  room,  in  the  after  end 
of  the  ship,  are  the  Captain's  quarters,  very 
small  and  compact.  One  of  the  two  berths 
shown  in  the  picture  is  Captain  MacMillan's. 
the  other  that  of  the  ship's  doctor,  official 
photographer  and  general  handy-man,  Ralph 
Robinson.  In  the  middle  of  the  cabin  stands 
the  Captain's  chart  table  with  its  chart  rack 


With  MacMillan  and  Radio,  North  of  Civilization 


503 


and  navigating  instruments.  Lining  the  upper 
wall  is  a  very  complete  library  of  scientific 
books.  The  forward  wall  presents  the  scene 
of  an  arsenal,  with  at  least  twenty  rifles,  ranging 
in  calibre  from  the  small  .22  equipped  with 
Maxim  silencer,  to  the  large  .401 -calibre  bear 
and  walrus  rifles. 

Small  side-arms  have  no  place  on  this  ex- 
pedition. As  a  matter  of  fact,  there  is  only  one 
revolver  on  the  ship,  and  that  is  owned  by 
Richard  Goddard,  representative  of  the  Car- 
negie Institute  of  Washington.  He  explained 
to  me  that  he  carries  it  only  for  protection  while 
away  from  the  ship  making  observations  in 
terrestrial  magnetism.  On  the  back  wall  of  the 
Captain's  quarters  are  fastened  two  delicate 
chronometers,  which  are  being  checked  by  the 
radio  time  signals  from  Arlington  each  day. 
For  this  purpose  an  extension  wire  has  been 
run  from  the  Zenith  receiving  set  in  the  for- 
ward part  of  the  ship  to  a  position  directly 
alongside  the  chronometers,  which  position  is 


incidentally  directly  alongside  the  head  of  the 
Captain's  berth.  While  the  extension  was 
primarily  for  setting  the  chronometers,  the 
Captain  sometimes  lies  in  his  berth  with  the 
headphones  over  his  ears  and  listens  to  the 
concerts  that  are  being  broadcasted  from  the 
stations  along  the  Atlantic  Coast  and  from 
WJAZ,  Chicago,  and  WOC,  Davenport,  Iowa. 

UP  FORWARD,  WHERE  THE  RADIO  SHACK  IS  i 

THE  forward  end  of  the  ship  is  taken  up 
with  the  forecastle,  comprising  the  radio 
room,  living  and  sleeping  quarters  of  the  crew, 
and  the  galley.  The  radio  room  is  in  the  peak 
of  the  forecastle,  berths  for  six  men  are  along 
the  sides,  the  mess  table  is  in  the  centre,  and 
the  galley  in  the  after  end  of  the  forecastle. 

"I  tell  you,  things  were  lively  in  the  fore^ 
castle  when  the  radio  started!  In  such  close 
quarters,  it  made  as  much  noise  as  a  steam 
locomotive  tearing  up  and  down  the  passage- 
way!   The  first  night  it  was  in  operation  the 


THE  DECK,  FROM  THE  CROW  S  NEST 
The  Bowdoin  is  driving  north  under  sail  and  motor-power,  heavily  loaded  with 
drums  of  fuel  and  oil,  and  supplies  and  provisions  enough  to  last  several  years 


504 


Radio  Broadcast 


E.  F.  MCDONALD,  JR.,  WHO  TELLS  OF  EXPERIENCES  ABOARD  THE  "BOWDOIn" 

He  returned  from  Labrador  recently,  having  left  the  expedition  there  after  accompanying  it  from  Wiscasset,  Maine.  Mr. 
McDonald  is  connected  with  station  WJAZ,  in  Chicago,  which  is  keeping  in  constant  communication  with  the  Bowdoin 

and  is  sending  out  special  programs  for  those  on  board 


cook  arose  in  great  consternation,  believing 
bedlam  had  broken  loose.  He  rubbed  his  eyes 
furiously,  finally  discovered  the  source  of  the 
disturbance,  and  exclaimed:  '1  have  been  ship- 
mates with  a  lot  of  powerful  snorers,  but  never 
with  such  a  noisy  beast  as  that  there  animal.' 
Strangely  enough,  however,  a  few  nights'  com- 
panionship with  the  set  made  its  noise  as  un- 
disturbing  as  the  town-clock  to  a  good  New 
Englander,  and  every  man  of  us  was  able  to 
sleep  as  soundly  as  a  village  constable. 

THE  EXPEDITION'S  RECEPTION  IN  NOVA  SCOTIA 

SYDNEY,  Nova  Scotia,  was  our  first  import- 
ant stopping  place.  Anchor  was  dropped 
at  North  Sydney  the  first  night  because  of  the 
intense  fog.  Next  day  found  the  Bowdoin 
gracefully  gliding  into  Sydney  Harbor  amid 
the  roar  of  salutes  from  the  French  gunboat, 
Regains,  anchored  in  the  harbor.  At  first  the 
cannonading  worried  us,  because  we  had  heard 
the  night  before  of  a  strike  waging  in  the  coal 
mines  and  steel  mills,  of  Canadian  troops  mov- 
ing in,  and  of  threatening  trouble.  But  our 
doubts  soon  gave  way  to  delight  over  the  warm 


reception  and  extreme  courtesy  of  which  the 
cannonading  was  the  first  evidence.  The  guns 
were  not  turned  toward  us.  This  was  July 
first.  I  shall  never  forget  what  a  thrill  it  gave 
to  see  the  American,  Canadian  and  French 
flags  flying  from  the  Royal  Sydney  Yacht  Club, 
and  from  public  buildings  and  private  resi- 
dences. Such  was  the  interest  shown  in  the 
MacMillan  exploration  trip  on  the  national 
holiday  of  the  Canadians. 

Sydney  is  the  outpost  of  civilization — the 
last  place  on  the  trip  showing  signs  of  modern- 
day  progress.  Here  Captain  MacMillan  had  his 
last  ice  cream.  Considering  the  climate  of  the 
Polar  regions,  he  will  probably  be  able  to  bear 
the  separation  from  ice  cream  fairly  well. 

Leaving  Sydney  we  headed  northeast 
through  a  dense  fog  and  caught  only  a  glimpse 
of  Newfoundland  as  we  passed  by.  This  was 
Port-aux-Basques.  Fog  whistles  blew  at  other 
points  along  the  Newfoundland  shore,  but  only 
at  the  one  point  did  the  fog  lift  its  veil  long 
enough  to  permit  a  view.  Likewise  most  of 
the  coast  of  Labrador  remained  a  mystery  to 
us.    Often  we  thought  land  directly  ahead,  but 


With  MacMillan  and  Radio,  North  of  Civilization 


505 


as  we  approached  the  dim  outline  of  the  sup- 
posed land  there  was  gradually  revealed  the  form 
of  an  iceberg.  So  many  icebergs  strewed  the 
way  that  traveling  was  exceedingly  dangerous. 

PUFFINS  AND  ICEBERGS 

OUR  first  stop  in  Labrador  was  in  back  of 
Greeneley  Island,  at  night  and  under  cover 
of  fog.  Next  day  when  the  sun  rose,  about 
3:00  a.  m.,  we  found  ourselves  within  100  yards 
of  shore.  Had  it  not  been  for  the  wonderful 
navigating  of  Captain  MacMillan,  we  should 
many  times  have  been  piled  on  the  rocks  along 
that  formidable  Labrador  shore.  Captain  Mac- 
Millan made  this  stop  to  visit  and  examine 
Paraquet  Island, which  isa  rookery  of  the  puffin. 
These  puffins  are  known  as  the  "  Parrots  of 
the  Arctic,"  are  wonderfully  colored,  have  the 
characteristic  parrot  bill,  but  feed  on  fish. 
Millions  of  them  swarm  the  island  which  is 
scarcely  a  mile  square. 

To  bring  the  puffins  out  of  their  hiding 
places,  it  was  only  necessary  for  us  to  lie  on  the 
ground  for  about  five  minutes.  Then  the  heads 
began  to  bob  up  all  around.  We  took  some 
specimens  of  these  birds  and  also  some  of  the 
eggs.  These  are  as  large  as  hens'  eggs  and 
are  one  source  of  food  to  the  natives. 

While  the  Captain,  Fairbanks  and  I  were 
on  this  island,  three  of  the  crew  decided  to 
.  visit  their  first  iceberg.  Directly  after  they 
left  it,  the  iceberg  decided  to  turn  over.  It 
was  interesting  to  hear  the 
Captain  tell  these  men,  upon 
their  return,  of  the  lurking 
dangers  of  the  iceberg.  Para- 
quet Island  is  located  in  the 
Canadian  Labrador  Section. 
On  the  mainland,  half  a  mile 
away,  a  tent  was  pitched  in 
open  view.  This,  we  were 
later  informed,  belonged  to 
the  Government  Game 
Warden,  but  the  Canadian 
Government,  although 
equipping  him  most  excel- 
lently in  every  other  way, 
failed  to  furnish  him  with  a 
boat! 

FOG,  AND  A  FORBIDDING 
COAST 


permitted  us  to  see  land.  The  curtain  very 
accommodatingly  rose  as  we  passed  Point  Am- 
our, where  we  were  given  an  opportunity  to  take 
pictures  of  the  wreck  of  the  battleship  Raleigh, 
once  the  pride  of  the  British  Navy,  but  now 
piled  high  and  dry  on  the  rocks.  Even  her 
guns  are  still  mounted.  While  we  were  passing 
through  some  of  the  thickest  of  the  thick  fog, 
with  the  rocky  shore  of  Labrador  only  a  short 
distance  from  us  on  our  port  side  but  com- 
pletely shut  off  from  view,  the  cook,  who  was 
on  his  first  trip  to  the  Arctic,  came  on  deck; 
and  the  Captain,  pointing  towards  where  he 
knew  the  land  was,  said:  "Well,  Cooky,  how 
do  you  like  your  view  of  Labrador?"  The 
cook  gazed  intently  and  seeing  nothing  but  fog, 
asked:  "Is  it  always  like  this?"  "No,  not 
always,"  replied  the  Captain;  but  at  that  point 
Robinson  confided  the  surprising  information 
that  only  once  in  his  fifteen  years  of  Arctic 
exploration,  had  the  Captain  seen  the  whole 
coast  of  Labrador  without  fog.  The  coast, 
when  visible,  is  an  enormous  pile  of  unfriendly 
rocks. 

In  Captain  Cartwright's  "Journal  of  Labra- 
dor," written  143  years  ago,  he  says:  "In  sailing 
along  this  coast,  the  astonished  mariner  is 
insensibly  drawn  into  a  conclusion  that  this 
country  was  the  last  which  God  made  and  that 
he  had  no  other  view  than  to  throw  together 
there  the  refuse  of  his  materials  of  no  use  to 
mankind.    Yet  the  mariner  no  sooner  pene- 


AS  WE  passed  north  along 
L  the  coast  of  Labrador, 
it  was  seldom  that  the  fog 


ONE  OF  THE  BIG  ONES  PASSED  BY  THE  BOWDOIN 
Only  about  one-tenth  of  it  shows  above  the  water 


506 


Radio  Broadcast 


trates  a  few  miles  into  a  bay  than  the  great 
change,  both  of  the  climate  and  prospects, 
alters  his  opinion.  The  air  then  becomes  soft 
and  warm;  bare  rocks  no  longer  appear;  the 
land  is  thickly  clothed  with  timber,  which 
reaches  down  almost  to  high-water  mark,  and 
is  generally  edged  with  grass.  Few  stout  trees 
are  to  be  met  with,  until  you  have  advanced  a 
considerable  distance  and  have  shut  the  sea 
out."  Perhaps;  but  we  found  this  country 
dismally  cold,  barren,  rocky,  and  uninviting. 

The  natives  of  the  villages  who 
make  their  living  by  fishing  for  cod 
and  salmon  have  in  their  backyards 
piles  of  wood,  sometimes  1 5  to  20  feet 
high,  the  largest  piece  not  exceeding 
two  inches  in  diameter.  It  is  all  of 
scrub  growth.  The  missionaries  told 
us  that  in  the  winter  the  poor  inhab- 
itants must  travel  miles  and  miles 
with  their  dog  sleds,  quite  content  to  find  even 
this  scrub  growth.  It  is  true  that  the  air 
becomes  warmer  as  you  travel  inland,  but  it  is 
also  true  that  the  moment  it  does  become 
warmer  you  see  flies  as  you  have  never  seen 
them  before.  The  air  is  literally  thick  with 
them. 

There  is  snow  everywhere  on  the  mountain 
tops  and  enormous  balls  of  ice  on  the  shore. 
At  one  point  89  icebergs  were  visible  from  our 
crow's  nest.  One  of  these  icebergs  was  in  the 
form  of  an  arch,  so  high  that  had  we  been  sure 
the  water  was  clear  below  we  could  have  sailed 
our  ship  through.  The  very  names  of  the  bays, 
capes,  and  islands  indicate  the  hardship  that 
has  been  experienced  in  this  God-forsaken 
country.  Some  have  already  been  named. 
Here  are  others  strongly  descriptive: 


Mistaken  Cove 
Lower  Savage  Islands 
God  Haven 
Misery  Bay 
Cape  Farewell 
Death  River 

Dead  Man  Lake 


Cold  Foot  River 
Battle  Harbor 
Windy  Fickle 
Fly  Away  Cape 
Punch  Bowl 
Lost  Hope 


WHEN  THE  NATIVES  LISTENED-IN 

AS  WE  entered  each  of  these  Labrador  ports 
L  a  group  of  small  dories  would  invariably 
put  out  from  the  shore,  and  a  race  would  start 
among  the  fishermen  to  see  which  could  reach 
us  first.  After  the  usual  preliminaries  of  get- 
ting acquainted  they  would  ask:  "Is  there  a 
doctor  on  board?"  Next,  they  asked  for 
clothing  of  any  description.    We  found  many 


of  the  hardy  fishermen,  bronzed,  weather-worn, 
and  thin,  clothed  in  a  pair  of  old  cast-off- 
looking  oilskin  trousers,  a  threadbare  sweater, 
a  battered  pair  of  boots,  and  nothing  more. 
The  fishing  has  been  bad  for  the  past  two  years. 
There  is  an  abundance  of  fish  this  year,  but  the 
inhabitants  are  faring  poorly  because  of  the  en- 
ormous quantities  of  ice  which  tears  their  nets  to 
pieces  and  often  carries  them  away  completely. 
These  people  are  mostly  of  French,  Irish  and 
Scotch  descent.  In  one  port  a  native  offered 
us  lobsters  for  sale.  He  had  a  dozen 
and  apologetically  explained  that  the 
price  of  lobster  was  very  high  this 
year.  Having  left  the  States  but 
recently  the  argument  of  short  sup- 
ply and  over-demand  was  not  new 
to  us,  and  we  were  quite  prepared 
for  a  South  Water  Street  price.  So 
he  asked  the  exorbitant  figure  of  ten 
cents  apiece  for  the  lobsters. 

Wherever  we  went,  people  were  all  agog 
with  excitement  over  the  radio  carried  on  board. 
They  were  glad  of  visitors,  glad  of  the  chance  to 
exchange  courtesies,  but  glad  especially  to  view 
the  equipment  of  the  Bowdoin.  Their  wonder- 
ment struck  its  height  when  they  listened  to 
voices  and  music  from  far-away  places  in  the 
United  States,  the  land  which  they  know  but 
little,  and  none  had  seen.  It  was  gratifying 
to  notice  their  frank  and  open  reaction,  so 
childlike,  so  sincere.  Electric  lights,  tele- 
phones, and  such  developments  which  have 
long  been  "necessities"  with  us,  are  of  course 
only  names  to  these  people. 

On  July  4th,  with  the  icebergs  completely 
surrounding  us,  we  received  the  returns  of  the 
Dempsey  fight.  The  pool  which  we  started  on 
board  for  the  man  who  guessed  the  number  of 
rounds  that  the  fight  would  last  was  temporar- 
ily won  by  Jaynes,  the  engineer,  and  paid  to 
him  when  the  fight  had  gone  to  twelve  rounds, 
that  being  the  number  he  selected.  But  the 
money  was  promptly  taken  away  from  him  when 
the  fight  went  on  to  fifteen  rounds. 

In  Battle  Harbor,  Labrador,  where  I  left 
the  expedition,  we  were  met  at  the  dock  by  the 
doctors  and  nurses  of  one  of  those  wonderful 
institutions,  the  Grenfell  Mission,  where  self- 
sacrificing  men  and  women  give  their  time  and 
energy  without  remuneration,  caring  for  the 
sick  and  injured  that  are  brought  to  them  from 
miles  around.  Contact  with  them  was  especi- 
ally delightful.  They  made  an  indelible  im- 
pression for  their  devotion  to  a  noble  cause, 


What  Balloon  Racers  Did  With  Receiving  Sets 


their  unselfishness,  their 
genuineness  and  easeof  man- 
ner, and  their  lively  interest 
in  us  as  visitors.  They  vis- 
ibly enjoyed  everything 
quite  as  heartily  as  the  na- 
tives, but  had  the  added 
advantage  of  education  and 
refinement.  They  too  were 
absorbed  with  the  Zenith 
radio  outfit  and  not  only 
enjoyed  listening  to  the 
concerts  but  took  every  op- 
portunity to  dance  to  the 
strains  from  far-away  sta- 
tions, even  the  Edgewater 
Beach  Hotel  station  in  Chi- 
cago. 

What  1  enjoyed  as  much 
as,  if  not  more  than  any- 
thing on  the  whole  trip 
was  the  opportunity  to  get 
to  know  that  wonderful 
optimist,  Captain  Donald 
B.  MacMillan.  To  me,  his  optimism  is  un- 
paralleled. If  it  rains,  it  rains.  If  it  is  cold, 
it  is  cold.  If  there  is  a  mishap  of  any  kind, 
it  is  accepted  by  Captain  MacMillan  in  con- 
tented spirit,  and  in  full  confidence  that  no 
matter  what  occurs,  it  is  for  the  best.  He  never 
looks  backward,  always  forward.  He  sees  a 
bright  side  to  every  situation,  every  occurrence. 

Captain  MacMillan  and  his  crew  were  well 
and  happy  when  I  took  my  leave.  One  comfort- 
ing thought  over  the  separation  was  in  realizing 
that  communication  with  them  would  not  be 
cut  off  as  it  had  been  until  their  return  to  civi- 
lization on  previous  trips,  but  would  be  main- 


MacMILLAN — SKIPPER  OF  THE  "BOWDOIN' 


tained  by  means  of  the  first  radio  outfit  to  be 
introduced  to  the  land  of  the  Eskimo. 

Every  Thursday  at  midnight,  WJAZ,  the 
Zenith  Edgewater  Beach  Hotel  station  broad- 
casts a  summary  of  the  week's  news  to  these 
men  in  the  frozen  North,  together  with  mes- 
sages from  their  relatives  and  friends.  Hun- 
dreds of  miles  from  civilization,  utterly  sur- 
rounded by  ice,  they  will  yet  have  the  news  of 
the  world  as  quickly  as  we  at  home,  and  may 
relax  from  their  strenuous  vigils  to  listen  to  the 
identical  strains,  perchance,  to  which  their 
friends  in  the  States  may  at  that  very  moment 
be  dancing  on  the  polished  hotel  floors! 


What  Balloon  Racers  Did  With 
Receiving  Sets 

How  Contestants  in  the  National  Event  Held  on  July  4th  Obtained  Storm 
Warnings  and  Entertainment.   Their  Recommendations  for  Future  Races 


C TENANT  R.  S.  OLMSTEAD,  winner 
of  the  National  Balloon  Race  which 
started  from  Indianapolis  on  July  4th, 
attributes  his  success  in  a  large 
measure  to  radio.  Lieutenant  Olm- 
stead  said  that  during  the  early  part  of  the 
flight  the  air  was  remarkably  free  from  static, 


but  that  on  July  5th,  when  west  of  Buffalo  and 
at  an  altitude  of  8,000  feet,  he  experienced 
considerable  interference  during  a  period  when 
an  electrical  storm  was  brewing.  His  balloon 
was  equipped  with  a  standard  airplane  an- 
tenna— that  is,  about  300  feet  of  copper  wire. 
For  a  ground,  he  used  25  feet  of  three-foot 


5o8 


Radio  Broadcast 


copper  screening,  such  as  is  used  for  fly  screens. 
His  official  report,  in  part,  follows: 

"i  —  In  compliance  with  request,  there  fol- 
lows a  brief  account  of  our  experience  with  the 
radio  set '  Radiola  1 1 '  carried  on  the  U.  S.  Army 
Balloon  S-6  and  furnished  by  the  General 
Electric  Company. 

"2 — The  radio  installation  complete  with 
antenna  and  counterpoise  weighed  about  30 
pounds.  In  weight,  therefore,  it  represented 
roughly  one  bag  of  sand  ballast.  Both  Lieut. 
Shoptaw,  my  aide,  and  myself  agreed  many 
times,  upon  receiving  a  particularly  enlighten- 
ing bit  of  information,  that  it  was  worth  several 
times  its  weight  in  sand. 

"3 — Immediately  upon  taking  off,  we  drop- 
ped our  antenna,  connected  our  ground,  and 
made  plans  to  receive.  The  results  were  uni- 
formly good  from  the  start.  One  musical 
program  after  another  came  in  with  great 
clearness,  and  incidentally  the  returns  on  the 
Dempsey-Gibbons  fight,  round  by  round. 
There  seemed  to  be  music  in  the  air  at  all 
times  and  to  any  one  who  has  experienced  the 
monotony,  when  everything  is  going  well,  of 
the  hours  of  darkness  in  a  balloon-race  flight, 
the  value  of  such  restful  relief  therefrom  is  very 
evident.  It  materially  added  to  our  efficiency 
through  assuring  rested  nerves.    At  times,  the 


audibility  of  the  set  was  sufficient  to  allow  us 
to  leave  the  headset  hanging  to  the  side  of  the 
basket. 

"Now  for  the  more  primely  important  fea- 
tures of  having  such  an  instrument  along. 
From  Detroit,  Chicago  and  Schenectady, 
particularly  Schenectady,  we  received  quite 
definitely  the  weather  reports  consisting  of 
general  flying  conditions,  wind  directions  and 
velocities,  cloud  conditions,  and — of  great  im- 
portance— the  pressures  recorded  at  various 
important  cities.  This  information  was  quite 
conclusive  in  influencing  our  tactics  to  obtain 
a  suitable  direction  of  flight  in  order  to  obtain 
maximum  endurance  and  distance. 

"A  feature  which  should  be  added  to  the 
radio  set,  if  possible — one  which  we  keenly  felt 
the  need  of  while  out  of  sight  of  any  landmarks 
or  other  means  of  locating  our  position  or  rate 
and  direction  of  progress  over  Lake  Erie — is  a 
direction-finding  apparatus. 

"A  point  of  vital  importance  in  a  race,  and 
one  which  had  considerable  bearing  on  our  de- 
cision to  land  at  the  time  we  did,  was  the  ad- 
vice received  by  radio  of  the  location  of  our 
various  competitors  from  time  to  time.  At 
the  time  of  landing,  we  knew  that  all  but  three 
of  our  competitors  had  been  accounted  for,  and 
we  were  quite  certain  through  deductions 


LIEUTENANT  OLMSTEAD  JUST  BEFORE  THE  START 
is  shown  with  the  two-tube  dry-cell  outfit  which  helped  him  win  the  race.    Radio  rendered  material  assistance  to  the 
balloonists  through  the  weather  reports  sent  out  from  five  broadcasting  stations 


What  Balloon  Racers  Did  With  Receiving  Sets 


509 


from  information  previously  received  of  the 
progress  of  others  that  we  were  at  least  in  one 
of  the  three  winning  positions  and  eligible  for 
the  team  to  go  to  Belgium  for  the  International 
race.  Had  we  not  had  this  information,  we 
might  have  tried  to  cross  Lake  Ontario  without 
sufficient  ballast,  failure  in  which  would  have 
disqualified  us. 

"4 — My  recommendations  are  that  most 
emphatically  a  radio  set  should  be  installed  in 
every  racing  balloon;  that  directional  apparatus 
should  be  added,  and  that  two  head-sets  should 
always  be  provided." 

CAPT.  MILLER  PRAISES  RADIO 

BESIDES  Olmstead's  balloon,  the  three 
other  army  balloons  which  entered  in  this 
race  were  equipped  with  receiving  apparatus. 
Captain  Lester  T.  Miller  wrote  the  General 
Electric  Company  as  follows: 

"Lieut.  Brown  and  myself  during  our  flight 
found  your  set  worked  very  satisfactorily  in 
every  way.  As  you  know,  the  counterpoise 
we  used  was  a  seven-strand  copper  wire,  woven 
fifteen  times  about  our  basket.  For  our  aerial, 
we  used  300  feet  of  the  same  kind  of  wire. 
During  the  night  of  July  4  and  on  July  5,  we 
flew  at  an  altitude  of  about  4,000  feet.  All  our 
weather  reports  were  received  very  clearly;  in 
fact,  the  clearness  of  tones  surprised  both  of  us, 
as  they  were  clearer  than  our  regular  station 
sets  on  the  ground. 

"On  July  5,  after  8:30  a.m.,  we  flew  at  a 
higher  altitude,  and  at  heights  of  5,000  feet  and 
above  we  found  the  static  was  so  bad  that  we 
were  not  able  to  receive  satisfactory  signals." 

Ralph  Upson,  another  of  the  contestants  in 
the  race,  also  equipped  by  the  General  Electric 
Company  with  the  same  kind  of  a  receiving 
outfit,  says  there  was  a  total  absence  of  static  at 
3,000  feet.  For  six  weeks  preceding  the  race, 
Upson  had  used  the  set  in  his  home  and  had 
become  thoroughly  familiar  with  its  operation 
under  various  conditions.  One  of  the  uses  he 
planned  for  his  radio  outfit  in  the  race  was  to 
detect  thunder-storms  before  the  lightning  was 
visible,  so  he  took  pains  to  learn  how  the  static 
came  in  under  various  weather  conditions. 

Five  of  the  principal  broadcasting  stations 
had  arranged  to  send  out  special  weather  re- 
ports regarding  the  upper  air  currents  during 
the  first  night  of  the  race  and  the  following 
morning.    In  regard  to  this,  Upson  says: 

"Andrus,  my  aide,  acted  as  chief  radio  oper- 


A  SAIL  THROUGH  THE  SILVER  LINING 

This  photo  was  taken  by  Mr.  Ralph  Upson  from  his  own 
balloon,   during  the  national   race  which   started  at 
Indianapolis  on  July  4th 


ator.  He  began  listening-in  at  8:30  o'clock  the 
night  of  the  race.  At  first  he  could  hear  noth- 
ing but  code  signals,  concerts  from  various  sta- 
tions, and  a  radio  drama  that  was  being  sent 
out  from  a  Chicago  station.  For  an  hour,  this 
was  about  all  we  could  hear.  Then  at  9:45 
o'clock,  Central  time,  Andrus  picked  up  the 
latter  part  of  the  weather  report  being  broad- 
casted from  WGY  in  Schenectady.  We  heard 
just  enough  of  it  to  make  us  wish  we  had  heard 
the  entire  report.  However,  our  disappoint- 
ment was  short,  for  a  few  moments  later  the 
whole  report  was  repeated,  every  word  being 
received  clearly  and  distinctly.  It  was  just 
the  news  we  wanted. 

'As  a  result  of  the  information,  we  decided 
to  go  a  little  higher  but  not  to  try  any  high  alti- 
tudes unless  forced  to  it  by  thunder-storms. 
The  report  gave  us  full  confidence  of  reaching 
New  York  State,  and  possibly  New  England. 
Everything  seemed  so  favorable  that  I  turned 
in  to  sleep." 


What  You  Should  Know  About 


Condensers 

Condenser  Losses.  Variable  Air  Condenser  for  Radio  Use.  Disadvantage  of  the 
Conventional  Form  of  Condensers.    What  Materials  Are  Best  for  Condensers 

By  ALLEN  D.  CARDWELL 

PART  II 

Last  month  Mr.  Cardwell  explained  the  theory  underlying  the  construction  of  condensers  and  their 
function  in  electrical  circuits.  In  this  second  and  last  part  of  his  article,  various  practical  considerations 
are  taken  up,  with  the  purpose  of  showing  the  radio  enthusiast  how  to  select  the  best  apparatus.  As 
stated  last  month,  "If  receiving  set  owners  would  buy  their  variable  condensers  after  a  survey  of  the 
mechanical  and  electrical  characteristics  of  the  types  on  sale,  rather  than  from  a  comparison  merely  of 
general  appearance,  hearsay,  and  price,  there  would  be  less  trouble  with  thousands  of  receiving  sets  and 
less  apparatus  of  inferior  quality  on  the  market  ....  A  familiarity  with  good  and  bad  condenser 
construction  is  worth  any  enthusiast's  while  to  obtain." — The  Editor. 


IOSSES  in  the  dielectric  used  in  a  condenser 
are  one  source  of  signal  "damping" 
as  pointed  out  at  the  conclusion  of 
.  the  last  article.    These  losses  are 
high  in  solid  dielectrics  and  low  with 
air  dielectrics. 

The  first  thing  we  observe  when  a  condenser 
is  used  in  a  high-frequency  circuit  is  that  the 
current  may  be  dissipated  in  the  dielectric. 
Thus,  if  we  force  i  ampere  of  current  into  a 
condenser  and  when  it  discharges  we  only  get 
back  .9  amperes,  there  has  been  a  dielectric  loss 
of  .  1  ampere  due  to  the  creepage  across  the 
space  between  the  plates.  Some  of  the  current 
must  have  "leaked"  through  the  dielectric  or 
have  been  absorbed  in  the  dielectric  itself. 


These  losses  are  normally  too  small  to  measure 
when  the  dielectric  is  only  dry  air,  but  under 
certain  conditions  the  leakage  can  increase  to  an 
appreciable  extent.  In  a  solid  dielectric,  this 
loss  is  always  appreciable  and  accounts  in  one 
way  for  the  preference  of  radio  engineers  in 
using  air  as  a  dielectric  wherever  possible. 

The  next  effect  we  observe  is  that  some  of  the 
current  may  be  dissipated  in  the  conducting 
plates.  If  the  different  plates  are  so  assembled 
that  there  are  uneven  pressures  at  supporting 
points  or  along  the  frame,  we  have  loss  from 
"contact  resistance"  aggregating  a  fairly  high 
value. 

Again  we  have  condensive  effects  set  up  in 
any  insulation  used  to  support  the  condenser 


THREE  TYPES  OF  VARIABLE  AIR  CONDENSERS 
:  Up  and  Down  "  Motion — "  Cork-Screw  "  Type — Book  Leaf  Type 


walls.  Although  these  insulation  pieces  may 
not  be  intended  as  part  of  the  dielectric,  they 
are  sometimes  so  placed  as  to  be  in  the  elec- 
trostatic field  and  some  of  the  current  works 
into  this  supporting  insulation  and  causes 
losses  from  leakage,  and  from  a  source  we  call 
"dielectric  hysterisis."  Hysterisis  losses  are 
the  result  of  impurities  or  cellular  structure,  as 
in  wood,  where  the  arteries  of  the  grain  may 
have  innumerable  moist  passages  to  shunt  the 
current  from  point  to  point.  Thus  the  insul- 
ation may  pass  minute  currents  in  and  out  in- 
ternally and  may  refuse  to  yield  up  the  current 
with  a  uniform  speed — in  any  event  less  quickly 
than  the  dielectric  proper  and  thus  cause  re- 
sistance effects  merely  by  failing  to  discharge 
synchronously  with  the  main  dielectric.  This 
reveals  the  important  factor  of  time  or  rate  of 
discharge  in  dielectrics.  We  can  charge  a 
dielectric  material  such  as  paper  to  a  given 
potential  and  upon  short  circuiting  get  back 
most  of  the  charged  current,  but  if  we  short 
circuit  it  a  second  time  (after  a  minute  has 
elapsed)  we  may  get  back  additional  current 
which  we  did  not  think  was  still  in  the  dielectric 
or  paper. 

An  ideal  dielectric  is  perfectly  elastic  elec- 
trically. It  springs  back  to  its  normal  condi- 
tion of  equalized  potential  of  zero  grade  the 
instant  it  is  short  circuited. 

Another  consideration  is  the  possibility  of 
losing  a  certain  amount  of  current  by  "stray 
field"  or  parasitic  effects.  If  a  body  of  metal 
is  in  or  near  the  dielectric  field,  it  will  act  as  a 
supplementary  condenser  in  interaction  with 
one  or  the  other  sides  of  the  condenser  alter- 


511 


nately.  Thus,  with  many  receiving  sets,  the 
panel  is  shielded.  This  means  that  the  shield 
acts  as  part  of  the  condenser  and  in  doing  so, 
a  secondary  condenser  exists  and  losses  may  be 
caused  since  the  shield  may  have  conduction 
resistances  as  well  as  insulation  hysterisis  effects. 

The  losses  in  a  condenser  may  thus  be  sum- 
marized as  follows: 

1  Dielectric  leakage 

2  Dielectric  hysterisis 

3  Insulation  leakage 

4  Direct-current  resistance  in  plates 

5  Stray  field  capacity 

6  Insulation  hysterisis 

These  losses  can  be  reduced  to  such  a  point  that 
the  most  sensitive  instruments  devised  to  measure 
resistances  cannot  accurately  indicate  or  check  any 
losses  whatever.  This  is  not  an  exaggeration. 
It  does  not  mean,  however,  that  there  are  no 
losses,  but  that  the  losses  are  so  small  that  it  is 
impossible,  with  unusually  delicate  equipment, 
to  determine  them. 

Let  us  therefore  consider  various  designs  of 
variable  air  condensers  (with  which  we  are 
primarily  concerned).  Where  do  the  various 
types  of  such  condensers  excel  and  where  do 
they  fail  to  secure  proper  efficiency? 

A  variable  air  condenser  as  generally  de- 
signed consists  of  a  series  of  fixed  plates  of  semi- 
circular shape,  so  spaced  that  a  second  set  of 
similar  plates  can  intermesh  between  the  fixed 
plates.  The  fixed  plates  are  called  the  stator 
plates  and  the  movable  plates  are  called  the 
rotor  plates. 

We  can  vary  the  capacity  by  the  amount  of 


What  You  Should  Know  About  Condensers 


DIAL  SETTING 


DIAL  SETTING 


CURVES  FOR  "STRAIGHT  LINE"  AND  "DECREMETER"  CAPACITY  RANGES 
The  curve  at  the  left  shows  how  a  condenser  having  a  constant  capacity  increase  varies  for  wave- 
length when  used  with  a  given  coil.    The  curve  at  the  right  shows  how  an  eccentric-shaped  plate 
will  correct  this  and  give  a  constant  increase  in  wavelength  when  used  with  the  proper  inductance 


512 


Radio  Broadcast 


Three  new  types  of  coupling  condensers:  A — the  Jones  condenser  used  in  neutralizing  circuits;  re- 
vived recently  by  Allen  D.  Cardwell  for  use  with  the  capacity-coupled,  double-circuit  tuner; 

condenser 


-an  old  French  design,  re- 
C — a  navy  type  coupling 


intermeshing  of  the  rotor  and  stator  plates. 
The  variation  of  the  intermeshing  can  be  made 
to  cause  an  equal  increase  of  capacity  for  each 
degree  of  rotation.  This  may  be  an  advantage 
in  that  it  makes  the  controlling  dial  cause 
capacity  changes  directly  proportional  to  the 
number  of  degrees  through  which  the  condenser 
dial  is  turned,  but  it  does  not  increase  wave- 
length uniformly.  To  do  this,  an  eccentric 
shape  is  made  for  the  rotor  plates,  and  when 
used  with  a  given  coil  the  condenser  changes 
cause  a  straight-line  wavelength  variation. 
In  this  case  it  is  called  "linear"  because  its 
wavelength  variation,  shown  in  a  graph,  would 
be  a  straight  line.  At  the  same  time  the  ad- 
vantages of  the  "straight  line"  or  linear  shape 
are  relatively  small  for  ordinary  tuning,  com- 
pared with  the  added  cost  of  manufacture  and 
the  disadvantages  of  the  extra  cubic  volume 
required  for  given  capacity. 

A  variable  condenser  can  also  be  constructed 
so  that  the  plates  (generally  limited  to  two  in 


H 


1 


OPT 


METHODS    OF  PLATE 

SPACING 
The  top  system  is  most 
common — namely  the  use 

of  washers 

The  second  method  is 
more  accurate,  but  adds 
greatly  to  the  cost.  Each 
plate  is  hammered  into 
the  block  and  jammed 
tight 

The  third  system  is  re- 
markably economical  and 
is  made  by  punching  each 
plate  to  make  a  self-spac- 
ing collar 


practice)  are  moved  closer  or  farther  apart 
in  a  direction  at  right  angles  to  the  planes  of 
their  surfaces.  Owing  to  the  necessity  of 
using  a  thin  sheet  of  insulation  between  the 
plates  to  prevent  short-circuiting,  this  type  of 
condenser  will  not  vary  proportionately  with 
the  mechanical  control  variation.  As  the  space 
or  dielectric  thickness  decreases,  the  capacity 
increases  more  rap- 
idly than  the  turns 
on  the  threads  or 
knob- mechanism, 
because  the  amount 
of  solid  dielectric 
has  become  greater 
in  proportion  to  the 
amount  of  air  die- 
lectric and  most 
solid  dielectrics 
have  greater  spe- 
cific inductive  cap- 
acity. 

A  third  system 
for  a  variable  con- 
denser is  to  hinge 
two  plates  and  vary 
the  spacing  by  clos- 
ing or  opening  the 
free  ends,  as  a  book 
cover  is  opened  or 

closed.  In  this  type  of  condenser  the  capacity 
also  increases  rapidly  as  the  distance  between 
plates  is  reduced  beyond  a  certain  point  and,  as 
in  the  reciprocating  system,  a  good  capacity 
rating  is  secured  only  by  closing  up  the  dielec- 
tric gap  so  closely  that  short  circuiting  would 
occur  if  solid  insulation  of  some  type  is  not 
placed  in  the  electrostatic  field.  This  means 
an  air  and  solid  dielectric  are  used  so  that  what 
convenience  is  gained  in  higher  capacity  of  the 


ROTOR  PLATE  SHAPES 
A  is  the  normal  or  standard 
shape,  giving  a  "straight  line" 

capacity  increase 
B  is  an  eccentric  shape  to  give 
a  constant  wavelength  increase 
when  used  with  the  proper  coil 


What  You  Should  Know  About  Condensers 


513 


plates  when  close  together  is  thus  lost  by  the 
resistance  of  the  solid  dielectric. 

A  fourth  style  of  condenser  has  occasionally 
been  proposed — namely,  a  "screw  type"  in 
which  the  rotor  plates  are  cast  as  a  continuous 
"cork  screw."  Being  a  complete  circle,  the 
plates  can  double  the  capacity  per  plate  area 
and  increase  the  capacity  at  a  very  slow,  con- 
stant rate. 

Other  rudimentary  methods  of  varying 
capacity  have  been  used — for  example,  a  set 
of  moving  plates  sliding  along  grooves  into 
the  fixed  plates,  or  some  with  one  tube  tele- 
scoping over  another.  These  designs  have  in 
general  one  or  another  of  the  following  defects: 

1  The  increase  in  capacity  is  not  linear 

2  The  cost  of  production  is  too  high 

3  The  maximum  capacity  is  either  small  or 

secured  by  high  dielectric  losses 

4  The  mechanical  construction  is  not  strong  or 

is  clumsy  or  bulky 

5  Variable  settings  for  given  capacity 

For  tuning  receiving  circuits,  a  condenser 
should  occupy  small  space,  increase  wave- 
length evenly  with  all  changes  of  the  dial,  and 
have  a  large  range  of  capacity  from  minimum 
to  maximum. 

The  intermeshing-rotor  design  has  become 
the  standard  in  radio  practice. 

In  the  design  of  the  standard  variable  air 
condenser  a  number  of  mechanical  methods 


INSULATION  USED  TO  SUPPORT 
THE  ROTOR  FROM  THE  STftTOR 


are  followed.  In  spacing  the  plates  of  either 
rotor  or  stator,  washers  are  often  used.  These 
are  placed  on  supporting  rods  so  that  on  as- 
sembly a  plate  is  held  in  position  by  the  flat 
faces  of  the  alternating  spacers. 

This  system  has  disadvantages.  In  the 
first  place  the  spacers  require  tedious  hand 
assembly.  In  a  43-plate  condenser,  for  ex- 
ample, there  would  be  three  spacers  per  plate, 
or  in  all  129  spacers  to  be  set  as  well  as  22  phtes 
of  the  stator  and  21  plates  of  the  rotor.  Where 
the  spacers  are  also  used  on  the  rotor,  it  would 
entail  more  than  256  distinct  hand  motions 
aside  from  locking  the  end  plates  and  tighten- 
ing all  adjustments. 

In  itself,  the  labor  is  not  as  serious  as  the 
electrical  inefficiency.  A  certain  amount  of 
oil,  moisture,  or  surface  unevenness  is  cumu- 
lative where  each  spacer  touches  a  plate.  The 
resistance  is  thus  multiplied  by  the  256  or  so 
contacts  and  aside  from  any  other  losses,  the 
resistance  may  be  considerable.  Even  solder- 
ing the  joints  does  not  satisfactorily  overcome 
the  mechanical  weakness  of  the  design.  Fus- 
ing the  metal  would  be  the  only  way  of  assuring 
permanent  low  contact  resistance. 

A  better  method  of  design  is  to  cut  a  solid  die 
by  which  the  plates  are  cast  as  a  solid  part  of 
the  frame  support — usually  a  flat  semi-circular 
wall,  thus  supporting  the  plates  by  half  of  their 
circumference  and  having  minimum  resistance 
in  the  support.    This  type  of  condenser  with 


TWO  WAYS  OF  INSULATING  THE  STATOR  FROM  THE  ROTOR 
At  the  left,  the  rotor  is  supported  by  end  plates  of  insulation.    Either  rotor  or  stator  can 
be  grounded.    The  condenser  on  the  right  shows  a  design  in  which  the  rotor  is  part  of  the 
frame  connection,  permitting  the  use  of  less  insulation.    Only  the  rotor  can  be  grounded 


514 


Radio  Broadcast 


MECHANICAL  VERNIER 

This  type  gives  a  ratio  of  256  to  1 
which  is  truly  a  micrometer  control 


good  bearings  can  be  very  closely  spaced,  that  is, 
the  dielectric  thickness  or  clearance  between 
stator  and  rotor  can  be  extremely  small.  The 
cost  however  is  high,  due  to  the  shape  and  ac- 
curacy required. 

The  surfaces  of  the  plates  cannot  be  smoothed 
down  and  are  difficult  to  keep  free  from  dust 
which  will  quickly  cause  minute  short  circuiting 
paths.  Even  when  invisible  to  the  eye,  this 
dust  will  vary  the  capacity  as  it  accumulates. 

Again,  the  cast  condenser  requires  a  high 
degree  of  shielding,  and  its  eddy  current  losses, 
due  to  so  much  metal  serving  only  as  support 
and  not  as  true  plate  surface,  add  to  the  losses. 

A  third  type  of  spacing  can  be  used  by  cut- 
ting grooves  into  spacing  pillars,  or  posts,  into 
which  the  plates  can  be  set  with  remarkably 
accurate  spacing  and  with  proper  mechanical 
strength.  This  system  is  superior  in  its 
economy  and  efficiency  if  the  plates  are  properly 
fixed  in  the  grooves. 

The  proper  design  depends  upon  the  method 
of  fixing  the  contacts  so  positively  that  sur- 
face contact  resistance  is  avoided. 

For  the  rotor  element,  either  die  casting  or 
washer  spacing  can  be  used.  A  few  are  made 
in  which  the  rotor  plates  are  set  in  position  and 
the  hot  metal  poured  into  a  mould  to  form  the 
center  shaft. 

In  general,  we  may  say  that  the  conduction 
current  losses  due  to  washer  spacing  for  either 
stator  or  rotor  will  be  small,  but  the  accuracy 
of  the  spacing  will  be  difficult  if  washers  are 
used  for  the  stator.  Every  rotor  shaft  or  bear- 
ing will  eventually  wear  or  have  some  parallel 
plate  error,  and  an  ordinary  allowance  can  be 
made  for  this  occurring  on  the  rotor  if  the  stator 
plates  do  not  vary  also.  In  short,  by  keeping 
the  accuracy  of  spacing  in  the  rotor,  we  could 
reduce  the  spacing  to  half  of  that  required  for 


washer  spacing  in  both  rotor  and  stator  and 
hence  secure  high  capacity  for  the  amount 
of  plate  surface  used. 

The  real  difficulty  in  condenser  design  is  in 
arranging  the  support  of  the  rotor  and  stator 
and  in  insulating  them  from  each  other.  This 
involves  the  utmost  mechanical  strength  and 
is  most  commonly  attained  by  making  the 
frame  a  part  of  the  stator  system  and  insulating 
the  rotor  by  means  of  a  metal  bushing  set  in 
an  end  plate  of  insulation. 

Three  standard  ways  of  doing  this  are  used, 
and  in  each  case  there  are  decided  electrical 
disadvantages.  1  n  the  first  case,  where  the  end 
plates  are  large  insulating  masses,  the  di- 
electric hysterisis  losses  are  generally  consider- 
able. When  the  surface  of  the  insulator  is 
large,  the  possibility  of  conduction  across  the 
surface  is  greatly  increased.  In  the  second 
case,  the  bearings  are  supported  in  such  a  way 
that  the  bushing  becomes  part  of  the  dielectric 
and  suffers  also  by  having  a  large  metal-to- 
insulation  contact  surface,  thus  increasing  the 
dielectric  losses.  In  type  three,  the  insulation 
design  is  good,  but  the  mechanical  ruggedness 
is  low.  But  in  all  these  types  the  capacity  of 
the  operator's  hand  is  carried  to  the  dial  by  the 
rotor  shaft  and  is  bound  to  cause  some  body 
capacity  effects  in  tuning  regardless  of  shield- 
ing. 

It  is  therefore  desirable  to  reverse  the  usual 
procedure  and  instead  of  "grounding"  the 
stator,  to  ground  the  rotor.  This  means  that 
the  stator  is  insulated  from  the  frame.  The 
frame  can  then  be  attached  to  the  panel  and  by 
grounding  will  not  be  influenced  by  any  "body 
capacity"  brought  near  the  panel,  This  is  a 
highly  important  feature  in  tuning  long  dis- 


PLATE  VERNIER 

1  his  design  illustrates  a  simple  method  01  getting  a  ver- 
nier effect  by  the  use  of  a  single  plate  on  a  second  shaft 


What  You  Should  Know  About  Condensers 


515 


tance  stations  where  the  signal  current  is  so 
weak  that  any  variation  of  wavelength  in  the 
secondary  or  primary  due  to  stray  capacity 
fields  will  cause  the  desired  station  to  fade  out 
when  the  adjustment  is  fixed  and  the  hand 
removed  from  the  dial.  To  hold  the  station 
when  the  wavelength  setting  has  been  made  it  is 
therefore  necessary  to  ground  every  part  which 
may  directly  or  indirectly  be  affected  by  body 
capacity.  This  can  only  be  done  by  grounding 
the  stator.  Shielding  does  not  entirely  ac- 
complish the  desired  end  if  the  stator  and 
frame  are  grounded,  since  the  shaft  of  a  rotor 
is  part  of  the  high  potential  side  and  passes 
through  the  shield  and  panel. 

Another  feature  of  design  which  is  serious  in 
the  grounded  stator  type  is  the  method  of 
making  contact  with  the  moving  rotor.  If 
contact  is  made  by  friction,  the  amount  of  bear- 
ing surface  is  so  small  that  a  film  of  oil  or  dust 
or  other  foreign  matter  creeping  into  the  bear- 
ing causes  a  high  resistance.  To  avoid  this 
unusually  wide  bearings  must  be  used  or  a 
lead  of  flexible  wire  soldered  to  the  rotor  and 
carried  to  some  connecting  point. 

This  point  brings  up  the  subject  of  counter 
balancing.  A  condenser  bearing  gradually 
loosens  with  wear  and  can  eventually  become 
so  loose  that  the  rotor  will  slip  around  due  to 
its  own  weight  when  the  semi-circular  plates 
are  not  at  perfect  balance. 

Thus,  great  difficulty  is  caused  in  using  a 
loosened  condenser  mounted  with  the  shaft 

~7    ?  Note  that  although  the 
/         ratio  of  the  separate  ver- 
/  nier  plate  to  the  main 

sry  I  condenser  is  about  50  to  1 

#  s  at  maximum  it  is  less  than 

i"  4  to  1  at  minimum  set- 
^        _t     tings,   due   to  the  high 

  ttsis.eaj^  — r1     minimum  capacity  of  this 

0        Wi  5."$,*  «««•?.      MT"^        condenser  design 

horizontal  on  the  panel  as  is  generally  the  case. 
To  overcome  this  objection  some  manufacturers 
place  a  counter-weight  of  moulded  lead  on  the 
rotor  so  that  even  if  the  bearings  loosen,  the 
adjustments  will  not  be  altered  by  gravity. 
Other  manufacturers  resort  to  "two-side"  con- 
struction, dividing  half  the  rotor  and  half  the 
stator  plates  symmetrically  in  opposite  sides 
of  the  rotor  shaft.  Thus  the  same  objective 
is  attained.  Both  methods,  however,  add  to 
the  cost  of  the  condenser,  and  its  bulk,  and 
make  its  minimum  capacity  high.  Instead  of 
three  stator  support  rods  as  many  as  five  or  six 


THREE  TYPES  OF  ROTOR  CONNECTIONS 
A — Pig-tail  connection  used  for  many  rotor  contacts 
B — A  friction  "pig-tail"  spring  which  has  a  very  good  sur- 
face contact.    The  parts  are  moved  open  to  show  the 

relative  positions 
C — A  ball  bearing  which  can  be  used  on  rotor-grounded 
condensers.    This  affords  a  perfectly  centered  bearing 
not  subject  to  end  play 

posts  are  required  with  the  "two-side"  con- 
struction, multiplying  the  spacing  problem  pro- 
portionately. The  weight  of  the  stator,  when 
counter  balanced,  is  nearly  doubled.  All  this  can 
be  avoided  by  placing  a  friction  sleeve  on  the 
rotorshaft.  By  usinga  slotted  sleeve,  practically 
even  and  permanent  pressure  is  secured  which 
avoids  any  possible  slippage  from  gravity. 

A  debatable  issue  is  involved  when  the  ques- 
tion of  verniers  is  brought  up.  An  efficient 
condenser  which  has  a  firm,  even  bearing  re- 
quires no  vernier  when  used  by  an  experienced 
operator.  Because  some  types  of  receivers, 
such  as  regenerators,  require  very  critical  tun- 
ing, vernier  devices  are  often  used.  The  vernier 
may  take  the  form  of  a  second  condenser  of 
one  or  two  rotor  plates  built  on  the  frame  with 
the  main  condenser.  It  may  also  take  the 
form  of  a  gear  system  attached  between  the 
rotor  control  and  the  rotor  shaft. 

With  the  separate  condenser  vernier  there  is 
introduced  a  double  electrostatic  field — such 
that  when  the  main  condenser  is  set  the  small 
condenser  may  do  more  than  vernier — it  may 
increase  or  decrease  the  first  capacity  far  out 
of  proportion.  What  is  more  serious  is  the 
necessity  for  a  more  complicated  shielding  and 
insulating  system.  The  cost  is  considerably 
increased  and  the  design  mechanically  less 


5.6 


Radio  Broadcast 


rugged  in  all  cases,  since  one  shaft  must  be 
contained  inside  the  other  shaft  and  must  be 
fairly  loose  to  operate  at  all.  Possibility  of 
wear  or  disalignment  of  plates  can  easily  occur. 

A  mechanical  vernier  is  preferable.  By 
suitable  gearing,  a  real  vernier  ratio  is  secured. 
A  true  micrometer  effect  is  determined  only 
by  the  gear  ratio.  With  the  separate  condenser 
vernier,  the  ratio  of  increase  is  too  low.  Thus 
if  the  maximum  capacity  of  the  large  condenser 
is  500  mmf.  (micro-microfarads)  and  the  maxi- 
mum capacity  of  the  vernier  is  10  mmf.,  the 
ratio  is  50  to  1,  which  is  good.  Usually,  how- 
ever, the  interacting  capacity  of  the  vernier 
often  runs  up  to  50  mmf.  while  in  many  con- 
densers of  this  type  the  larger  units  hardly 
reach  400  mmf.  Thus,  in  practice,  the  ratio 
becomes  400  to  50  or  8:1  which  is  not  suffi- 
ciently large.  By  a  mechanical  vernier,  such 
as  a  rubber  roller  on  the  edge  of  a  3-inch  dial, 
the  ratio  is  about  6:1  which  is  also  too  low. 
The  best  solution  is  by  using  a  gear  in  which  a 
single  main  condenser  is  varied  by  a  ratio  of 
turn  of  50  to  1  or  higher.  This,  however,  is  not 
altogether  desirable  for  quick  tuning  and,  in 
general,  most  experienced  radio  operators  do 
not  like  verniers  preferring  to  use  a  circuit 
in  which  a  vernier  is  not  required.  This  is 
worth  careful  study.  Specially  designed  vernier 
dials  are  on  the  market  which  afford  an  80:1 
ratio,  and,  when  mechanically  rugged,  they 
offer  an  ideal  solution  of  vernier  controls. 

WHAT  MATERIALS  ARE  BEST  FOR  CONDENSERS? 

WE  MAY  now  discuss  the  various  types  of 
materials  used  in  the  manufacture  of 
the  condenser.  As  the  condenser  should  be 
light,  some  metal  such  as  aluminum  is  almost 
universally  used.  The  resistance  of  aluminum  is 
almost  as  low  as  that  of  copper.  Plates  of  alumi- 
num, if  more  than  .0025  inches  thick,  are  rea- 
sonably strong  and  will  not  be  easily  bent.  They 
are  also  springy  enough  to  stay  in  shape  even  if 
accidentally  pressed  or  hit,  if  made  from  hard 
stock.  Aluminum  also  makes  a  good  cast  frame. 
Sheet  aluminum  is  almost  universally  used  for 
the  plate  material.  It  can  be  polished,  and 
if  made  in  constant  thickness  and  of  high 
purity  it  is  satisfactory  in  all  respects.  Plates 
of  brass  and  some  other  metals  may  be  nickeled 
but  this  is  not  necessary  if  the  spacing  is 
greater  than  .05  inches  as  the  possibility  of 
dust  short  circuiting  the  plates  is  very  small. 
Aluminum  is  not  easily  corroded  under  ordi- 
nary conditions,  and  the  surface  resistance  is  not 


an  important  factor.  For  the  rotor  shaft,  a  good 
grade  of  case-hardened  steel  is  desirable.  The 
end  bearings  should  be  of  dissimilar  metal  from 
the  shaft  and  preferably  bronze  or  brass. 
Spacers  should  be  about  f  of  an  inch  in 
diameter  for  the  rotor.  On  the  three-post 
types,  used  for  stator  spacing,  washers  of  at 
least  f-inch  diameter  are  desirable.  The  bear- 
ings must  always  be  made  of  the  best  steel  and 
brass  and  where  pressure  is  exerted,  be  so 
assembled  that  the  wear  is  properly  taken  up 
by  adjusting  screws  so  that  after  long  use  the 
tension  or  position  of  the  plates  can  be  restored. 

"Pigtail"  connections  for  the  moving  ele- 
ment contact  are  generally  made  of  braided 
copper  wire  of  about  twelve  or  more  strands. 
If  ribbon  wire  is  used,  it  must  be  very  flexible 
and  not  subject  to  twists  when  coiling  or  un- 
coiling; or  a  flat  connector  like  a  watch-spring 
may  be  used. 

It  is  difficult  to  specify  the  best  kinds  of  in- 
sulation without  treading  on  trade  names  of  dif- 
ferent manufacturers.  Phenol  compositions  have 
good  insulation  characteristics  if  not  in  the  elec- 
trostatic field,  but  any  solid  material  is  bound 
to  cause  resistance  in  this  respect.  Fibrous 
materials  rank  somewhat  below  the  phenoiic 
compounds.  Hard  rubber  of  pure  composition 
is  particularly  good  for  supports  and  insulation. 
A  good  design  calls  for  the  smallest  possible 
contact  with  any  solid  insulation.  On  the  other 
hand  a  fixed  condenser  uses  a  good  deal  of 
insulation,  as  the  dielectric  and  the  resistance 
characteristics  then  play  an  important  part. 
Porcelain  is  electrically  good  but  mechanically 
poor  owing  to  its  brittleness. 

Back  of  all  these  factors  in  design,  workman- 
ship and  materials  is  the  basic  efficiency  of 
the  condenser — resistance.  No  beauty  of  as- 
sembly, no  perfection  of  material  or  conve- 
nience of  design  can  offset  resistance  effects. 
Furthermore,  if  the  condenser  has  only  a  low 
range  of  capacity  variation  it  is  inefficient  and 
if  it  has  proper  maximum  range  but  excessive 
bulk  it  is  also  undesirable. 

The  measurements  of  the  resistance  of  a 
condenser  are  extremely  difficult.  The  best 
way  is  by  a  comparison  test,  using  as  the  stan- 
dard a  special  condenser  with  plates  suspended 
by  silk  threads  and  all  stray  field  effects  care- 
fully isolated.  Such  a  measurement  involves 
very  delicate  and  accurate  devices  and  con- 
siderable engineering  skill.  The  rating  given 
must  be  based  upon  the  reputation  of  a  recog- 
nized authority. 


A  Bouquet  for  the  Broadcasters 

Editor,  "Radio  Broadcast" 

Dear  Sir:  I  am  deeply  impressed  by  the  re- 
quests which  come  so  often  over  the  radio  lor 
listeners-in  to  write  to  the  artists,  lecturers,  sing- 
ers, and  others  who  entertain  the  unseen  audience. 

It  seems  a  small  matter  to  write  such  letters, 
and  1  have  written  a  great  many;  but  I  think 
most  radio  fans  realize  that  it  is  impossible  to 
write  as  many  as  the  people  who  entertain  would 
hope  to  get,  and  I  should  like,  through  your  mag- 
azine, to  express  my  appreciation  of  the  enormous 
trouble  and  work  undertaken  by  these  stations, 
which  give  us  such  a  vast  variety  of  good  material 
suited  to  every  taste.  As  I  cannot  listen  to  the 
radio  and  write  letters  all  the  time,  I  ask  that 
you  may  find  room  for  this  letter  of  general  ap- 
preciation in  your  magazine. 

I  have  just  returned  from  a  trip  to  London, 
where  broadcasting  is  paid  for  through  a  license 
which  every  person  who  owns  a  receiver  must 
possess,  and  the  entertainment  provided,  both  in 
variety  and  quality,  as  well  as  in  amount,  is  in- 
significant compared  with  the  service  given  in  this 
country  without  pay.  I  am  sure  that  the  letters 
which  the  stations  receive  do  not  adequately  rep- 
resent the  gratitude  of  people  who  own  radio  re- 
ceiving machines. 

Very  truly  yours, 

F.  N.  DOUBLEDAY. 

A  Report  on  the  Grimes  "Inverse  Duplex" 

A MAGAZINE  for  and  about  radio  is  in 
somewhat  different  relation  to  its  "  Dear 
Readers"  than  most  other  periodicals,  in  that 
there  is  more  correspondence  with  the  editor. 
There  is  quite  a  bit  of  familiarity  and  good 
fellowship.  There  are  many  bouquets  received 
and  some  brick-bats — which  we  are  happy  to 
say  are  much  in  the  minority.  We  do  try  to 
make  our  magazine  helpful  as  well  as  entertain- 
ing, and  we  like  to  know  that  our  efforts  meet 
with  your  approval.  For  this  reason  we  are 
always  glad  to  receive  letters  such  as  this  one, 
from  those  who  have  successfully  followed  the 
instructions  in  our  "  How  to  Make  It"  articles. 

Gentlemen: 

I  wish  to  extend  my  thanks  for  your  article  in  the 
April  number  of  Radio  Broadcast.  "1,300  Miles 
With  a  One  Foot  Loop,"  and  especially  for  the 


wiring  diagram  of  the  Grimes  Inverse  Duplex 
receiver.  Shortly  after  reading  the  article  I  set 
about  building  an  Inverse  Duplex.  I  have  had 
several  types  of  receivers,  including  crystal  detector, 
ultra-audion,  plain  VT  detectors,  and  three-circuit 
regenerators,  including  variometer  and  variocoupler 
tuners  and  triple  spider-web  tuners  and  this  set 
(Inverse  Duplex)  sure  has  them  all  beat.  Although 
on  the  loop  it  is  not  quite  so  loud  as  some  of  the  other 
sets  with  a  two-stage  A.  F.  amplifier,  the  ease  of  tun- 
ing, freedom  from  interference  and  other  noises  more 
than  make  up  for  the  slight  decrease  in  the  volume. 
Several  of  my  friends  have  heard  it  and  say  it  is 
better  than  any  they  have  ever  heard. 

In  the  four  weeks  I  have  been  using  this  outfit 
there  has  been  only  one  night  when  I  could  not  hear 
anything.  One  night  when  static  was  quite  bad  on 
outdoor  aerial  outfits,  I  could  cut  through  to  WGY 
1,000  miles  with  very  little  annoyance  from  static, 
on  the  loop. 

Thanking  you  again  for  the  article,  and  for  all  the 
other  interesting  articles  in  your  magazine  I  am 
Sincerely  yours, 
Arthur  E.  Tabraham 
Bloomington,  111. 

Selling  Records  by  Radio 

AS  SOON  as  someone  suggests  selling 
L  by  radio,  most  thumbs  go  down.  How- 
ever, it  is  being  done,  and,  to  a  great  extent, 
being  so  well  done  that  we  are  all  learning 
to  like  it.  Good  publicists  have  been  able 
to  "sell"  religion  by  making  it  entertaining; 
plays  and  operas  have  been  "sold"  to  the 
public  and  lately  we  find  that  the  large  movie 
houses  can  sell  their  entire  program  by 
letting  the  radio  audience  hear  a  part  of  the 
good  music  that  drowns  the  click  of  the  pro- 
jector as  the  silent  drama  is  screened.  In  the 
accompanying  letter  our  correspondent  outlines 
a  very  practical  plan,  which,  it  would  seem, 
could  be  brought  into  action  with  satisfactory 
results. 
Dear  Sir: 

I  wish  to  make  a  suggestion  of  a  plan  whereby 
radio  and  the  phonograph  might  be  made  to  cooper- 
ate with  each  other  instead  of  conflicting  and  com- 
peting as  they  do  now.  The  history  of  the  telephone 
and  the  telegraph  shows  us  that  one  can  never 
entirely  eliminate  the  use  of  the  other,  but  that  the 
development  of  the  entire  field  of  use  for  both 


What  Our  Readers 
Write  Us 


5i8 


Radio  Broadcast 


together  has  made  the  share  of  business  of  each 
invention  much  greater  than  if  one  interest  had  en- 
tirely eliminated  the  other. 

At  present  the  phonograph  people  have  the  best 
talent  in  the  country  under  contract  and  are  able 
to  pay  large  sums  for  good  entertainment.  The 
broadcasting  stations  are  still  furnishing  high  class 
entertainment,  but  when  performing  before  the 
microphone  has  lost  some  of  its  novelty  the  problem 
of  paying  the  artists  and  collecting  from  the  radio 
public  will  have  to  be  solved. 

My  plan  is  this:  Use  radio  broadcasting  to  ad- 
vertise phonograph  records.  1  don't  mean  to  broad- 
cast phonograph  music  by  any  means,  for  everyone 
knows  how  little  satisfaction  there  is  in  tuning  a 
radio  set  just  to  get  a  poor  reproduction  of  phono- 
graph music  that  you  can  listen  to  first  hand  with 
no  trouble  at  all.  But  why  cannot  the  microphone 
of  some  good  broadcasting  station  be  installed  in 
the  studio  where  records  are  being  made  by  famous 
artists  and  give  the  radio  public  a  free  sample  of 
what  the  next  issue  of  records  is  going  to  be  like  so 
that  they  will  want  to  go  down  and  buy  the  record. 

The  movies  are  running  short  parts  of  films  to 
advertise  coming  attractions,  new  foods  are  often 
advertised  by  free  samples,  the  circus  gives  a  free 
show  or  parade  to  advertise  the  main  attraction,  the 
music  stores  all  have  concert  rooms  to  play  the  new 
records  for  prospective  customers,  so  why  shouldn't 
the  record  manufacturers  avail  themselves  of  the  ab- 
solutely free  means  of  handing  out  a  sample  of  part 
or  all  of  a  few  of  their  coming  issues  of  records  to 
many  thousands  at  a  time  of  a  class  of  people  that 
are  all  interested  in  good  music  and  a  large  share  of 
whom  are  owners  of  phonographs? 

Very  truly  yours, 

Fred  W.  Temple 
Lenwood  Hospital 
Augusta,  Georgia. 

Playing  the  Game 

IT  IS  doubtful  that  the  devotees  of  any  pas- 
time are  more  sportsmanlike  than  radio 
enthusiasts.  It  is  true  that,  for  a  time,  there 
was,  and  in  some  few  places  there  still  is,  a 
squabble  between  the  folks  interested  in  broad- 
cast reception  only,  and  those  out  and  out 
brass-pounders  who  are  now  known  as  "  hams." 
Wherever  any  ill-feeling  is  found,  it  is  more  than 
likely  to  result  from  a  mutual  misunderstanding 
and  it  may  be  smoothed  over  by  a  chat.  Such 
chats  usually  require  more  than  average  good- 
will and  gumption  on  the  part  of  one  of  the 
people  concerned  and  there  are  not  enough  of 
such  people.  The  suggestions  made  by  our  cor- 
respondent, who  signs  himself,  "A  Ham," 
may  make  such  chats  unnecessary  and  life 
more  livable  for  all  of  us. 


Dear  Sir: 

Within  the  past  few  months  we  have  seen  a  great 
many  receiving  circuits  exploited  in  radio  maga- 
zines and  radio  sections  of  the  newspapers.  Some 
of  these  circuits  are  nothing  more  than  modifications 
or  complications  of  circuits  that  have  been  known 
for  some  time.  In  many  instances  their  chief  ad- 
vantage consisted  in  giving  the  magazine  or  paper 
something  to  describe  and  radio  dealers  something 
to  sell.  When  the  time  came  for  performance,  man) 
of  these  outfits  produced  nothing  but  disappoint- 
ment. Many  novices  attempted  to  construct  these 
circuits  and  after  they  have  invested  their  good 
money  for  the  purchase  of  parts  to  build  up  these 
so-called  phenomenal  receivers,  found  that  it  was  not 
difficult  to  eliminate  one  half  or  more  of  the  parts 
and  secure  about  the  same  results,  and  by  so  doing, 
getting  back  to  the  original  circuit  of  which  the  new 
circuit  was  a  complication. 

It  happens  that  a  great  many  of  these  receivers  are 
of  the  radiating  type,  that  is,  they  are  made  in  ex- 
actly the  same  fashion  as  radio  telephone  transmit- 
ters except  that  they  are  made  to  operate  on  con- 
siderably less  power.  The  fact  that  they  do  trans- 
mit cannot  be  questioned. 

The  efficiency  of  these  receivers  is  obtained  in  a 
manner  that  in  the  long  run  can  do  nothing  but 
harm  the  radio  business.  This  is  particularly  notice- 
able in  the  case  of  the  Reinartz  and  the  Flewelling 
circuits.  The  case  of  the  single-circuit  regenerative 
receiver  has  received  so  much  attention  that  it  is 
unnecessary  to  discuss  it  further  here,  but  in  com- 
parision  to  these  other  receivers  it  is  actually  a  mild 
transmitter. 

If  radiating  receivers  are  used  close  to  each  other, 
we  find  that  a  great  deal  of  whistling  results.  Take 
for  instance  an  apartment  house  with  five  or  six 
antennas  all  leading  to  regenerative  receivers  that 
are  in  almost  an  oscillating  condition.  Suppose 
two  or  three  of  them  are  tuned  in  on  the  same  dis- 
tant broadcasting  station  and  for  some  reason  or 
other  the  signals  from  this  station  become  weak. 
The  operators  of  the  three  receivers  begin  very  deli- 
cate adjustments  to  build  up  this  signal  strength 
and  in  doing  so  one  of  them  may  reduce  his  wave- 
length; another  may  go  up  on  his;  and  the  third 
may  satisfy  himself  with  increasing  his  regeneration 
to  the  point  of  oscillation.  Nothing  more  than  a 
din  is  the  result.  Sooner  or  later  this  type  of  re- 
ceiver will  be  a  thing  of  the  past,  for  there  are  indica- 
tions, even  now,  that  other  types  of  receivers  may 
be  made  which  will  perform  equally  as  well  without 
causing  this  interference.  In  the  meantime  the 
sportsmanlike  thing  to  do  is  to  manipulate  your  re- 
ceiver in  such  a  manner  as  to  permit  your  neighbors 
to  secure  the  benefits  from  theirs  that  you  would  like 
to  receive  from  yours.  This  may  be  done  if  the  re- 
ceiver is  kept  well  below  the  oscillating  condition. 

One  serious  cause  of  disturbance  is  utilizing  what 
is  called  "zero  beat "  reception.    Zero  beat  reception 


What  Our  Readers  Write  Us 


519 


is  brought  into  play  by  getting  the  regenerative 
or  plate  circuit  in  exact  resonance  or  tune  with  the 
incoming  signals  and  is  a  very  difficult  method  to 
employ  satisfactorily.  You  can  recognize  the  fact 
that  you  are  employing  zero  beat  reception  when 
tuned  to  a  given  station,  you  find  that  by  moving 
your  wavelength  dial  a  hair's  breadth  to  the  left  or 
right,  you  are  greeted  by  a  whistle.  That  whistle 
means  that  you  are  going  slightly  above  or  slightly 
below  the  wave  of  the  transmitting  station  and  the 
wave  of  your  regenerative  receiver  combines  with 
the  incoming  wave  from  the  transmitter  and  pro- 
duces what  is  called  a  beat  note.  This  beat  note  is 
picked  up  by  other  receivers  in  your  neighborhood 
and  if  these  receivers  are  connected  to  amplifiers 
and  loud  speakers,  the  result  is  a  pronounced  shriek 
which  is  doing  more  to  injure  radio  than  any  other 
agency. 

Have  you  ever  invited  a  number  of  friends  in  to 
listen  to  a  concert  in  which  you  thought  they  would 
be  particularly  interested?  For  a  while  the  magic 
music  may  be  delightful  and  at  about  the  time  that 
everyone  concludes  that  radio  is  a  very  wonderful 


thing,  one  of  the  shrieks  to  which  we  are  referring 
comes  out  of  the  loud  speaker.  Those  who  are  unfa- 
miliar with  radio  are  astounded.  Their  eyes  widen 
and  it  is  not  unlikely  that  someone  will  exclaim: 
"What  is  that  horrible  noise?  If  this  is  radio  I'll 
take  the  phonograph." 

There  are  two  methods  for  eliminating  this  in- 
terference. The  first  is  by  operating  your  receiver 
below  the  oscillating  point;  the  second  is  by  adding  a 
single  stage  of  radio-frequency  amplification  before 
the  detector.  It  is  well,  in  determining  upon  the 
receiver  you  ought  to  build,  to  find  out  whether 
or  not  the  circuit  you  contemplate  employing  will 
radiate.  It  is  better  to  employ  some  circuit  that 
will  permit  long  distance  reception  without  inter- 
fering with  your  neighbors,  who  in  turn  have  the 
privilege  of  employing  a  similar  arrangement  to 
interfere  with  you  and  continued  back-biting  of  this 
sort  is  as  disagreeable  to  the  innocent  bystander  as 
to  the  quarrelers  themselves.  Will  you  do  your 
share  to  make  radio  better  for  everybody? 

A  "Ham" 
Chicago,  111. 


IS  IT  PITTSBURGH,  MR.  GALLAGHERS       "NO,  CHICAGO,  MR.  SHEAN 
Gallagher  and  Shean,  the  not  unknown  comedians,  are  here  shown  behind  the  scenes  waiting  for  their  act  to  go  on,  listening- 
in  to  some  station,  the  exact  location  of  which  was  not  teamed,  owing  to  the  fact  that  when  the  photographer  left,  they 
were  still  arguing  as  to  whether  it  was  Chicago  or  Pittsburgh 


The  "Lab"  department  has  been  inaugurated  by  Radio  Broadcast  in  order  that  its  readers  may  bene- 
fit from  the  many  experiments  which  are  necessarily  carried  on  by  the  makers  of  this  magazine  in  their  en- 
deavors to  publish  only  "fact  articles"  backed  by  their  personal  observations. 

Under  this  heading  will  also  be  published  practical  pointers,  brief  write-ups  of  interesting  experiments,  ad- 
ditions to  and  improvements  on  previously  published  circuits — in  short,  anything  of  genuine  value  and  in- 
terest to  the  reader,  which,  due  to  the  brevity  with  which  it  can  be  covered,  does  not  justify  a  special  article. 

Radio  Broadcast  will  be  pleased  to  buy  from  its  readers,  at  prices  from  three  to  five  dollars,  com- 
mensurate with  the  value  of  the  data,  kinks,  devices,  original  ideas,  etc.,  with  photographs  if  possible,  which 
the  editor  may  consider  eligible  for  this  department. 

Address  all  communications  to  the  R.  B.  Lab  Editor. 

PLAYING  WITH  THE  GRIMES  CIRCUIT 


THE  Grimes  Inverse  Duplex  receiver, 
which  has  been  described  in  several 
past  issues*  of  Radio  Broadcast, 
has  proven  on  merit  the  most  popu- 
lar of  the  many  reflex  circuits.  How- 
ever, there  is  little  doubt  that  the  original  cir- 
cuit admits  of  considerable  improvement,  and 
the  attention  of  not  only  the  inventor  but  of 
individual  experimenters  has  been  devoted  to 
this  effort.  Experiments  by  this  department 
have  resulted  in  data  which  will  be  of  interest 
to  the  reader  engrossed  in  the  complications  of 
this  ingenious  circuit. 

The  Radio  Broadcast  experiments  were 
roughly  divided  into  two  parts:  ascertaining  the 
possibilities  of  different  kinds  of  tubes  in  de- 
tecting and  amplifying  combinations,  and 
investigating  the  possibility  of  increased 
signal  strength  through  regeneration. 

In  all  cases  it  was  found  that  reception  was 
much  improved  by  the  inclusion  of  a  grid  con- 
denser and  leak  in  the  detecting  circuit,  rather 
than  the  direct  metallic  connection  indicated 
in  many  diagrams. 

The  following  combinations  were  attempted, 

*For  circuits  and  further  constructional  data,  see  the 
April,  July,  August,  and  September  issues  of  Radio 
Broadcast. 


reception  being  effected  on  the  small  two-foot 
loop  shown  in  the  photograph  (Fig.  i),  all 
comparative  tests  being  made  on  Station  WOR, 
fifteen  miles  away: 

1 .  Using  three  UV-201  's  for  both  amplifiers 
and  detector:  The  result  was  a  very  stable  set, 
and  reception  was  little  affected  by  adjustment 
of  the  limiting  potentiometer.  Signal  strength 
was  fair  in  the  headphones,  but  weaker  than  in 
any  of  the  succeeding  experiments. 

2.  Using  201  's  in  the  amplifier  and  a  UV- 
200  in  the  detector:  Signal  strength  was  con- 
siderably improved,  but  the  set  became  more 
critical,  and  howled  unmercifully  on  certain 
adjustments.  This  might  have  been  obviated, 
however,  by  biasing  the  amplifier  tubes. 

3.  Using  UV-199's  throughout:  Signal 
strength  was  equal  to  test  number  two,  but 
best  results  were  not  secured  until  the  tubes 
were  varied  from  detector  to  amplifier  sockets 
and  the  most  efficient  combination  determined. 

However,  distortion  was  particularly  notice- 
able with  these  tubes  when  an  amplifying  plate 
voltage  over  forty  was  employed,  and  sixty  to 
eighty  volts  was  required  for  the  highest  intensi- 
fication. Biasing  the  grids  of  both  amplifying 
tubes  with  three  volts  negative,  improved  mat- 
ters, reconciling  quality  to  amplification. 


In  the  R-B-lab  521 


FIG.  I 

Trying  a  plate  variometer  in  the  detector  circuit  of  the  Grimes  receiver.  UV- 
199's  are  in  the  amplifying  sockets  and  a  W.  E.  215-A  in  the  detector  socket 


The  limiting  potentiometer  was  here  found 
quite  necessary. 

4.  Using  UV-199's  for  amplifiers  and  a 
215-A — (W.  E.  peanut  tube)  for  the  detector: 
It  was  first  discovered  that  these  last  tubes  are 
not  altogether  uniform.  One  of  three,  how- 
ever, proved  an  excellent  detector,  and  this 
combination  gave  results  superior  to  any  of  the 
preceding  experiments.  Signals  were  suffi- 
ciently loud  to  operate  a  small  loud-speaker, 
though  on  more  distant  stations  we  should 
advise  an  additional  stage  of  separate  A.  F. 
amplification. 

On  each  of  the  foregoing  combinations,  re- 
generation was  attempted  by  both  the  tickler 
feed-back  and  variometer  methods.  The  form- 
er system  was  found  unstable  when  it  had 
any  effect  whatever,  and  results  did  not  justify 
the  expense  and  clumsiness  of  the  extra  wind- 
ing on  the  loop. 

However,  using  a  standard  variometer  in  the 
plate  circuit  of  the  detector,  in  experiment 
three,  had  a  marked  effect  of  regeneration,  and 
signal  strength  was  considerably  improved. 
In  tests  one  and  two,  it  proved  critical  and  un- 


stable, while  in  the  last  it  produced  lirtle  or  no 
effect. 

From  the  foregoing  experiments,  the  follow- 
ing conclusions  may  be  arrived  at: 

1.  A  grid  condenser  and  leak  are  desirable 
to  the  efficient  operation  of  the  Grimes  circuit. 

2.  Howling  and  general  instability  of  the 
circuit  can  be  reduced  and  reception  improved 
by  biasing  the  grids  of  the  amplifying  tubes. 
(See  page  123,  June  1923  Radio  Broadcast.) 

3.  Certain  qualities  in  some  detector  tubes 
antagonistic  to  the  best  reception  can  be 
remedied  by  the  use  of  a  plate  variometer. 

4.  The  plate  variometer  is  especially  valu- 
able with  the  UV-199  tube. 

5.  On  the  whole,  an  extra  regenerative 
system  in  combination  with  the  Duplex  is 
neither  desirable  nor  practicable. 

MAKING  YOUR  GRID-LEAKS 

(Photograph  and  data  contributed  by  Carter  Fiske) 

GRID-LEAKS  of  different  values  are  es- 
sential to  the  most  efficient  operation  of 
radio  receiving  circuits,  and  poor  results  with 
many  homemade  regenerative  sets  have  been 


522 


Radio  Broadcast 


traced  to  an  improper  grid  adjustment.  The 
enthusiast  who  is  becoming  an  experimenter 
should  be  equipped  with  the  means  of  varying 
the  grid-leak  on  the  various  tubes  and  sets 
with  which  he  is  experimenting.  A  variable 
leak  is  of  course  one  solution,  but  many  of 
these  are  unsatisfactory,  and  as  there  are  often 
several  sets  in  the  shop,  the  most  economical 
plan  is  to  supply  one's  self  with  a  dozen  or  so 
homemade  fixed  resistances. 

A  very  efficient  leak  can  be  made  by  coating 
a  small  piece  of  card  or  bristol  board  with 
Higgins'  Waterproof  'White  Label'  India  ink. 
Different  resistances  are  obtained  by  repeated 
coatings  of  ink. 

The  bristol  board  is  cut  into  small  strips  an 
inch  and  a  half  long  by  a  quarter  of  an  inch 
wide.  They  are  coated  on  one  side  to  within 
an  eighth  inch  of  each  end  by  applying  the 
undiluted  ink  with  the  quill  furnished  on  the 
stopper  (Fig.  2).  The  resistance  of  three 
quarters  of  one  inch  of  single  coating  is  approx- 
imately 5  megohms  (5,000,000  ohms);  of  two 
coatings,  2\  megohms;  five  coatings,  1  megohm, 
and  so  on.  The  experimenter  is  advised  to 
make  up  a  collection  of  resistances  from  5 
megohms  to  one  half  megohm. 

The  exact  resistances  of  the  leaks  can  be 
determined  if  the  enthusiast  possesses  a  micro- 
ammeter  or  a  galvanometer  calibrated  in 
fractions  of  an  ampere.  It  will  merely  be 
necessary  to  connect  the  leak  in  series  with  a 
high-voltage  battery  (from  one  hundred  to 


fig.  2 

Making  the  grid  leak.    The  India  ink  is  applied  to  the 
surface  of  the  bristol  board,  the  number  of  applications 
determining  the  resistance 


one  hundred  and  fifty  volts)  and  the  meter, 
read  the  current  indication,  and  apply  Ohm's 
law  (see  article  beginning  on  page  496,  this  is- 
sue) which  states  that  the  resistance  is  equal 
to  the  voltage  divided  by  the  current. 

In  a  large  laboratory,  the  resistance  of  the 
grid-leak  would  be  measured  directly  by  a  very 
interesting  instrument,  an  English  invention, 
known  as  the  Megger.  This  instrument  is 
fundamentally  nothing  more  than  a  D.  C. 
meter  reading  in  ohms  directly,  rather  than 
volts  or  amperes.  The  Megger  supplies  its 
own  potential  by  means  of  a  small  hand-driven, 
250-volt  generator.  The  ingenious  part  of 
the  instrument  exists  in  the  differential  winding 
of  the  meter  which  automatically  compensates 


for  any  variation  in  the  voltage  caused  by  the 
inconstant  speed  of  the  generator.  If  a  grid- 
leak  is  connected  to  a  Megger  of  the  proper 
range,  and  the  handle  turned,  the  needle  will 
indicate  on  the  scale  the  exact  resistance  of  the 
exterior  circuit. 

The  ingenuity  of  the  experimenter  will 
devise  numerous  ways  of  mounting  the  India 
ink  resistance.  A  convenient  method  of  mount- 
ing is  suggested  in  Fig.  3,  where  the  resistance 
element  is  slipped  under  two  brass  or  copper 
strips  screwed  to  a  small  block,  base,  or  panel. 

BUILDING  YOUR  OWN  LABORATORY 

A WELL  equipped  radio  laboratory  is  the 
ambition  and  dream  of  the  true  fan.  A 
laboratory,  however,  unlike  Aladdin's  palace, 
is  not  to  be  built  overnight.  Rather  the  vari- 
ous tools  and  equipment  are  slowly  accumu- 
lated with  experience  and  as  the  pocket-book 
allows.  But  the  building  of  a  laboratory  can 
be  greatly  facilitated  if  its  acquisitions  and 
purchases  are  effected  with  the  advice  and 
under  the  supervision  of  those  who  have  paved 
the  way. 

Radio  Broadcast  plans  to  devote  a  section 
of  this  department  to  the  interest  of  those 
readers  who  are  slowly  adding  to  their  equip- 
ment, laying  the  foundation  of  a  genuine  radio 
lab.  Every  month,  if  space  permits,  one  or 
two  instruments  or  tools  well  within  the  fi- 
nancial resources  of  the  average  reader  will  be 


Broadcasting  Stations  in  the  U.  S. 


suggested  as  additional  equipment,  and  their 
functioning  or  use  carefully  explained. 

Fig.  4  shows  two  pieces  of  laboratory  equip- 
ment, a  small  hand-drill  and  a  wet  cell,  the  first 
being  indispensable  for  rapid  and  accurate 
construction,  and  the  latter  most  useful  as  an 
always  ready  auxiliary  or  spare  battery.  The 
hand-drill  will  cost  from  two  to  three  dollars, 
and  should  be  purchased  along  with  an  18  and  a 
27  drill.  These  sizes  will  pass  respectively,  an 
8  and  a  6  screw,  the  two  sizes  most  commonly 
encountered  in  radio  work.  The  hand-drill 
may  be  used  on  wood,  bakelite,  hard  rubber, 
etc.,  and  on  metal.  It  is  equally  useful  in 
drilling  cabinets,  panels,  or  brass  and  steel 
supporting  brackets.  It  is  many  times  more 
rapid  than  the  cumbersome  brace  and  bit. 

The  wet  cell  equals  in  voltage  the  dry  cell, 
and  in  emergencies  it  may  be  temporarily 
substituted  for  the  latter.  However,  it  is  not 
recommended  for  continual  service  due  to  rapid 
polarization,  an  effect  that  renders  the  battery 
inoperative. 

The  wet  cell  costs  about  seventy-five  cents, 
and  renewals  (zinc  and  sal-ammoniac)  perhaps 
fifteen  cents.    When  it  is  desired  to  use  the 


fig.  4 

Two  useful  additions  to  the  amateur  laboratory 

battery,  six  ounces  of  sal-ammoniac  are  dis- 
solved in  the  jar  two-thirds  filled  with  water. 
It  is  suggested  that  when  the  cell  has  done  its 
duty — perhaps  rescued  a  concert  which  a  fail- 
ing dry  cell  would  no  longer  bring  in  well- 
that  the  solution  be  bottled  and  the  carbon 
cylinder  and  zinc  rod  dried.  The  battery  is 
now  ready  for  the  next  emergency,  and  with 
such  care  renewals  will  not  be  necessary  for 
several  years. 


Supplemental  List  of  Broadcasting  Stations  in  the  United  States 

LICENSED  FROM  JULY  14  TO  AUGUST  7  INCLUSIVE 


CALL 
SIGNAL 


FREQUENCY  WAVE- 

(  Kilocycles)  length 


POWER 
WATTS 


KFBC  Nielson  Radio  Supply  Co.,  Phoenix,  Ariz. 

KFIY  Brott  Laboratories,  Seattle,  Wash  

KFIZ  Daily  Commonwealth,  Fond  du  Lac,  Wis.  . 

KFJC  Post  Intelligencer,  Seattle,  Wash  

KFJF  National  Radio  Mfg.  Co.,  Oklahoma  City,  Okla. 

KFJH  The  Sugar  Bowl,  Selma,  Calif  

KFJI  Liberty  Theatre,  Astoria,  Ore.  .     .     .  . 

KFJK  Delano  Radio  &  Elect.  Co.,  Bristow,  Oklahoma. 

KFJL  Hardsoog  Mfg.  Co.,  Ottumwa,  Iowa. 

WSAU  Camp  Marienfield,  Chesham,  N.  H  

WSAW  Curtice  &  McElwee,  Canandaigua,  N.  Y.  . 

WTAF  Gallo,  Louis  J.,  New  Orleans,  La  


1260 

238 

10 

1270 

236 

15 

I  100 

273 

100 

1290 

233 

100 

1 190 

252 

20 

1 100 

252 

10 

1 190 

252 

10 

[290 

233 

100 

1240 

242 

10 

1310 

229 

10 

1090 

275 

100 

1240 

242 

20 

DELETIONS  FROM  JULY  1  TO  JULY 


WIZ 


Eugene,  Ore. 

WMAD 

Casper,  Wyo. 

WMAW 

Denver,  Colorado 

WNAB 

Marshalltown,  Iowa. 

WNO 

Greenwich,  Conn. 

WPAS 

Lake  Forest,  III. 

WPI 

Carthage,  III. 

WQAJ 

Waterford,  N.  Y. 

WQAK 

Washington  C.  H.,  Ohio. 

WQAT 

Binghamton,  N.  Y. 

WRAN 

Saginaw,  Mich. 

WSAA 

Cincinnati,  Ohio. 

WTP 

Dayton,  Ohio. 

Rockport,  Mo. 
Wahpeton,  N.  D. 
Bowling  Green,  Ky. 
Jersey  City,  N.  J. 
Amsterdam,  N.  Y. 
Clearfield,  Pa. 
Ann  Arbor,  Mich. 
Dubuque,  Iowa. 
Richmond,  Va. 
Waterloo,  Iowa. 
Marietta,  Ohio 
Bay  City,  Mich. 


New  Equipment 


EVEREADY  THREE  . 
RADIO  BATTERY 
This  battery  merits  every 
radio  set  user's  attention.  It 
may  be  used  as  an  A  battery 
for  receivers  employing  UV- 
199's,  as  a  B-battery  booster 
for  any  tube  set,  and  as  a  C 
battery  for  any  amplifier. 
Size  4"x3"xi|",  140Z.,  3  to 
45  volts.  The  booklet  de- 
scribing the  uses  of  this  little  battery  may  be  had  from 
the  National  Carbon  Company,  Inc.,  Long  Island  City, 
N.  Y.     Price,  70  cents 


A  VERNIER  VARIOMETER 

Made  by  the  National  Chelsea  Radio  Cor- 
poration. It  has  a  wide  inductance  range, 
is  ruggedly  built,  and  is  intended  for  either 
panel  or  table  mounting.     Price,  $8.00 


manufacturers.  Workrite 


A  TUNED  R.  F. 
TRANSFORMER 

Designed  for  use  in 
neutrodyne  circuits, 
but  suitable  for  any 
arrangement  em- 
ploying tuned  radio 
frequency.  Informa- 
tion regarding  its  use 
in  various  circuits 
may  be  had  from  the 
Manufacturing  Company, 


Cleveland,  Ohio.    Price,  ?2.oo 


THE  R.  M.  C.  VARIOCOUPLER 

This  is  one  of  a  number  of  tuning  instruments  made 
by  the  Radio  Manufacturing  Company,  of  Springfield, 
Massachusetts.  With  a  pair  of  variometers  of  similar 
construction,  this  variocoupler  may  be  used  to  advan- 
tage in  the  construction  of  a  good  three-circuit  receiver 


A  BROADCAST  RECEIVER  EMPLOYING  THE  NEUTRODYNE  PRINCIPLE 
Two  steps  of  radio-frequency  amplification,  detector,  and  one  step  of  audio  gives  enough  volume  to  operate  a  loud 
speaker.    The  tuning  is  accomplished  by  special  Telos  variometers.    Dials  C1  and  C2  control  the  neutrodyne 
condenser,  in  order  that  the  various  values  of  capacity  in  the  tubes  employed  may  be  compensated  for 


RADIO  BROADCAST  ADVERTISER 


"What  panel  shall  I  use?" 


ONE  of  the  first  questions  you  probably 
will  ask  yourself  when  you  get  ready  to 
build  your  radio  set  will  be  about  the  choice 
of  a  good  panel.  Your  answer  will  determine, 
to  a  large  extent,  the  efficiency  of  your  set. 

Of  course  you  want  a  panel  that  has  superior 
insulating  properties.  Celoron  Radio  Panels 
are  used  by  fans  who  appreciate  the  value  of 
a  good  radio  panel.  They  have  high  dielectric 
strength  and  great  volume  and  surface  resis- 
tivity. Celoron  panels  are  uniform  in  quality, 
and  do  not  warp  or  crack. 

You  will  find  Celoron  panels  easy  to  saw, 
drill,  and  tap.  They  engrave  evenly  without 
feathering,  and  enable  you  to  build  a  set  that 
is  neat  and  attractive  as  well  as  efficient. 

Approved  by  Uncle  Sam 

Celoron  Radio  Panels  are  approved  by  the 
U.  S.  Navy  Department  Bureau  of  Engineer- 
ing and  the  U.  S.  Signal  Corps.  Many  of  the 
leading  manufacturers  of  radio  equipment 
use  Celoron  in  their  standard  parts. 


Each  panel  is  wrapped  separately  in  glass- 
ine  paper  and  carries  complete  instructions 
for  working  and  finishing.  Ask  your  dealer  for 
one  of  the  following  sizes: 


1—  6x  7xi 

2—  7x  9x1 

3—  7  x  12  x  i 

4—  7  x  14  x  ft 


5—  7  x  18  x  ft 

6—  7x  21  x  ft 

7—  7  x  24  x  ft 

8—  12  x  18  x  ft 


We  also  furnish  Celoron  in  full-sized  sheets 
and  can  cut  special  sizes  if  desired.  If  your 
dealer  has  not  yet  stocked  Celoron  panels, 
ask  him  to  order  for  you,  or  write  direct  to  us. 
Indicate  by  number  the  size  you  want. 

Send  for  free  booklet 

Our  booklet,  "  Tuning  in  on  a  New  World," 
contains  a  list  of  the  leading  broadcasting 
stations  in  the  United  States  and  Canada, 
several  efficient  radio  hook-ups,  and  an  ex- 
planation of  the  symbols  used  in  radio  dia- 
grams. Write  at  once  and  be  sure  of  getting 
yours  before  the  supply  is  exhausted. 


To  radio  dealers:  Send  for  special  dealer  price  list  showing  standard  assortments 


Diamond  State  Fibre  Company 


BRIDGEPORT 


PENNSYLVANIA 


(near  Philadelphia) 

BRANCH  FACTORIES  AND  WAREHOUSES 
BOSTON  CHICAGO  SAN  FRANCISCO 

Offices  in  Principal  Cities 
In  Canada:  Diamond  State  Fibre  Company  of  Canada,  Limited,  245  Carlaw  Ave.,  Toronto 


STANDARD  RADIO  PANEL 


■^r  Tested  and  approved  by  Radio  Broadcast  if 


526  Radio  Broadcast 

New  Equipment — Continued 


FILAMENT  LIGHTING  FROM  A  LAMP  SOCKET 
Is  now  possible  where  alternating  current  of  1 10  or  220 
volts  is  available.  This  little  machine  will  furnish 
enough  current  for  the  lighting  of  more  than  a  dozen 
6  volt  tubes.  It  is  being  included  by  several  manu- 
facturers of  complete  receivers  as  standard  equipment 
and  is  the  first  machine  to  be  marketed  as  a  substitute 
for  the  storage  battery.  Simplex  Electrical  Laborator- 
ies, Inc.    144  Livingston  St.  Brooklyn,  N.  Y. 


The  Grid 

QUESTIONS  AND  ANSWERS 

The  Grid  is  a  Question  and  Answer  Department  maintained  especially  for  the  radio  amateurs.  Full 
answers  will  be  given  wherever  possible.  In  answering  questions,  those  of  a  like  nature  will  be  grouped 
together  and  answered  by  one  article.  Every  effort  will  be  made  to  keep  the  answers  simple  and  direct, 
vet  fully  self-explanatory.  Questions  should  be  addressed  to  Editor.  "  The  Grid  "  Radio  Broadcast, 
Garden  City,  N.  Y. 


A  Tuned  Plate  Circuit 

Will  you  please  publish  a  hook-up  containing  the  following 
equipment,  and  explain  the  functioning  of  each  piece  of  ap- 
paratus: 

One  variometer 

One  43-plate  condenser 

One  stage  tuned  radio-frequency  amplification 
One  stage  audio-frequency  amplification 
About  how  far  should  such  a  set  receive  ? 

C.  P.,  Norristown,  Pa. 

WE  APPEND  thediagram  which  our  correspondent 
desires,  in  Figure  1.  It  is  suggested  that  the  in- 
struments be  mounted  in  the  left  to  right  order 
indicated  in  the  diagram,  and  on  a  panel  not  shorter  than 
twelve  inches. 


Ci  is  the  43-pIate  condenser  which  tunes  the  wavelength 
to  which  the  loop  responds.  This  last  is  simply  constructed 
and  the  reader  is  referred  to  this  department  for  May,  in 
which  clear  directions  are  given  for  building  it. 

Potentiometer  R3  varies  the  charge  on  the  grid  of  the 
first  tube,  according  to  the  position  of  the  slider  or  knob, 
which  may  be  varied  between  the  positive  and  negative 
terminals  of  the  A  battery.  This  variation  is  called  bias- 
ing and  permits  the  radio-frequency  tube  to  be  operated 
at  its  most  efficient  grid  potential,  and  results  in  maximum 
amplification  with  a  minimum  of  distortion. 

Variometer  V  comprises  the  tuned  plate  circuit  in  which 
the  radio-frequency  amplification  is  effected  in  a  manner 
not  easy  to  explain  to  readers  unfamiliar  with  radio  theory. 
Its  functioning  is,  perhaps,  most  easily  disposed  of  by  stat- 
ing that  it  offers  infinite  impedance  to  the  currents  of  the 


qh  — 1|  1 


90V. 


FIG.  I 


RADIO  BROADCAST  ADVERTISER 


Magnavox  %adio 

^producers  and  oAmplifiers 

IT  has  been  the  dream  of  every  Radio  user  to  own  in  one 
unit  a  Power  Amplifier  and  electro-dynamic  Reproducer, 
thus  insuring  perfect  radio  reproduction.  The  new  instru- 
ments of  the  unit  type  here  illustrated  in  one  and  two  stages 
of  amplification  may  be  had  through  dealers  everywhere. 

There  is  now  a  Magnavox  for 
every  receiving  set.  The  full  line 
embraces: 

Magnavox  Reproducers 

R2  with  18-inch  curvex  horn  .  .  .  $60.00 
R3  with  14'inch  curvex  horn  .  .  .  35.00 
Ml  wi:h  14'inch  curvex  horn.  Requires 


New  Magnavox  Combination 
Set  Al-R 


no  battery  for  the  field 

Magnavox  Combination  Sets 

Al-R  consisting  of  electro'dynamic 
Reproducer  with  14-inch  curvex 
horn  and  1  stage  Amplifier 

A2-R  consisting  of  electro-dynamic 
Reproducer  with  14-inch  curvex 
horn  and  2  stage  Amplifier 

Magnavox  Power  Amplifiers 

Al — new  1-stage  Power  Amplifier  . 
AC-2-C — 2 -stage  Power  Amplifier  . 
AC-3-C — 3-stage  Power  Amplifier  . 


35.00 


59.00 


85.00 


27.50 
55.00 
75.00 


The  new  Magnavox  semi-dynamic  Reproducer  M-i,  designed  for  dry  battery  receiving  sets, 
is  also  of  great  interest  to  radio  users.  Write  for  complete  catalog. 

THE  MAGNAVOX  CO.,  Oakland,  Cal. 

*New  York  Ojfice:  370  Seventh  Avenue 
PERKINS  ELECTRIC  CO.,  LTD.,  MONTREAL,  CANADIAN  DISTRIBUTORS 


if  Tested  and  approved  by  Radio  Broadcast  -fc 


528 


Radio  Broadcast 


wavelength  to  which  it  is  tuned,  with  the  result  that  the  os- 
cillations which  would  ordinarily  return  through  the  vario- 
meter are  forced  upon  the  grid  circuit  of  the  succeeding  tube. 

The  grid  condenser  and  leak  (GC)  function  for  the  detec- 
tor tube  much  after  the  manner  of  the  potentiometer  in  the 
R.  F.  amplifier,  and  maintain  the  electrical  condition  of  the 
detecting  grid  in  the  state  most  conducive  to  detection. 

C2  is  a  telephone  bypass  or  shunt  condenser  of  the  usual 
type,  generally  .002  mfd.  capacity,  and  may  be  purchased 
for  thirty-five  or  fifty  cents.  It  passes  radio-frequency 
currents  in  the  detector  tube  which  otherwise  would  be 
impeded  by  the  high  reactance  of  the  primary  of  the  audio 
amplifying  transformer.  This  passage  of  the  R.  F.  current 
has  a  slight  effect  of  regeneration,  and  while  not  altogether 
necessary  on  this  type  receiver,  it  often  improves  operation. 

The  audio  transformer  merely  relays  the  output  of  the 
detector  on  to  the  amplifying  tube,  where  it  is  intensified, 
and  finally  sent  through  the  phones  or  loud-speaker. 

The  receiving  possibilities  of  such  a  set  rest  largely  upon 
the  experience  of  the  operator,  and  in  the  winter  season 
reception  distances  may  range  anywhere  from  one  hundred 
to  a  thousand  or  more  miles. 

Winding  Spider-Web  Coils 

/)/  the  May,  1923,  issue  of  Radio  Broadcast  appeared  an 
article  by  Walter  Van  B.  Roberts  describing  "A  Single-Tube 
Loop  Set  in  a  Brief-Case."  The  article  mentions  that  the 
grid  and  tickler  coils  are  wound,  spider-web  fashion,  "over 
three  and  under  three."  I  should  appreciate  it  if  you  would 
illustrate  in  a  drawing  just  how  these  directions  are  to  be 
carried  out. 

M.  S.,  Coney  Island,  N.  Y. 

THE  "over  three  and  under  three"  method  of  winding 
can  be  used  to  advantage  for  any  receiving  set  pro- 
vided that  the  number  of  turns  and  diameter  of  the 
coils  are  suited  to  the  wavelengths  on  which  it  is  desired  to 
receive.  The  accompanying  illustration  (Fig.  2)  shows  how 
the  inductance  is  to  be  wound.  Starting  at  the  inside  end 
of  any  one  of  the  "spokes",  the  wire  passes  over  three 
"spokes"  (looking  edgewise  at  the  wheel  or  winding  form) 
and  then  under  three,  round  and  round  until  the  wire  has 
packed  up  the  required  distance  from  the  inside  ( 1  f"  in  the 
case  of  the  coil  described  by  Mr.  Roberts).  Nineteen 
spokes  should  be  used,  but  if  a  form  having  greater  or  less 
than  nineteen  is  more  convenient,  almost  any  reasonable 
number  may  be  employed.  Care  should  be  taken,  however, 
that  the  number  of  "spokes"  is  always  divisible  by  three, 
plus  one,  i.  e.,  ten  "spokes"  (nine  plus  one),  thirteen 
"spokes",  twenty-two,  etc. 


The  winding  form  is  generally  made  in  one  of  two  ways: 
it  may  be  built  up  of  wooden  spokes  (such  as  toothpicks) 
stuck  into  the  edge  of  a  small  wooden  or  heavy  cardboard 
disk;  or,  perhaps  the  more  simple  method,  by  cutting  out 
the  complete  form  from  fibre  or  heavy  cardboard,  as  Mr. 


FIG.  2 

Roberts  did  (see  tickler  coil  in  photo  on  page  18,  May 
issue.) 

Any  one  who  contemplates  winding  his  own  spider-webs 
will  do  well  to  read  the  clear  and  detailed  instructions  on 
pages  428  and  429  of  Radio  Broadcast  for  March,  1923. 
In  that  case,  4s  toothpicks  were  used,  the  wire  being  wound 
over  two  and  under  two. 

A  Three-Circuit  Layout  with  Amplifier 

Since  becoming  a  reader  of  your  excellent  publication,  I 
am  contemplating  the  construction  of  a  regenerative  receiver 
built  in  such  a  manner  that  two  stages  of  amplification  can  be 
conveniently  added  to  the  same  at  a  later  date.  Will  you 
kindly  furnish  a  diagram  of  the  wiring,  as  well  as  a  drawing 
showing  the  approximate  si\e  of  the  panel  and  the  placing  of 
the  various  tuning  instruments  ?  I  intend  to  use  a  vario- 
coupler  and  two  variometers.  How  many  taps  should  there 
be  on  the  variocoupler  ? 

H.  A.  K.,  Fergus  Falls,  Minn. 

IT  IS  suggested  that  H.  A.  K.,  and  readers  interested  in 
similar  apparatus,  build  the  tuner  and  detector  in  a  sin- 
gle cabinet,  and  later,  if  desired,  the  two  steps  on  a 
separate  panel  and  according  to  the  instructions  detailed 
in  the  article  on  amplifiers  appearing  in  the  July  issue  of 
Radio  Broadcast.  The  circuit  diagram,  and  the  preferred 
order  in  which  the  instruments  may  be  mounted,  are 
shown  in  the  Fig.  3  and  Fig.  4,  which  also  suggests  the 
desirable  dimensions  for  the  panels. 

The  number  of  taps  on  the  variocoupler  will  vary  with 
the  make,  averaging,  perhaps,  ten.  The  better  instru- 
ments are  tapped  in  both  units  and  groups  of  turns,  neces- 
sitating two  rows  of  taps  and  two  switch  levers,  but  elimin- 
ating the  series  antenna  condenser. 

This  receiver  is  the  renowned  amateur  standby  and  in  the 
opinion  of  many  operators,  it  is  without  peer  for  distance, 
loudness,  and  selectivity.  It  was  a  set  of  this  type  that 
won  Radio  Broadcast's  "How  Far"  contest. 


>  .  -  V£ 

_L1C 


VARIO 
COUPLER 


18V 1  40- 60V 
ljl|l|l|l|l|l|l|l|l|l|l|lh— 


FIG.  3 


RADIO  BROADCAST  ADVERTISER 


Midgets  in  size — but  giants  in  power 


IMAGINE  a  radio  storage  battery  so  light  you 
can  lift  it  on  the  palm  of  your  hand,  but 
powerful  enough  to  supply  all  the  current  you 
need  for  long-distance  receiving — and  then  some! 

The  new  two-  and  four-volt  Exide  A  Batteries 
for  low-voltage  tubes  weigh  only  five  and  six 
pounds  each.  And  they  are  wizards  of  efficiency — 
right  in  step  with  the  latest  developments  in 
radio  receiving. 

These  sturdy  little  batteries  are  neat  and  com- 
pact. They  were  specially  designed  for  WD- 11 
and  UV-199  vacuum  tubes,  but  can  be  used  with 
any  low-voltage  tube.  The  two-volt  Exide  A  Bat- 
tery consists  of  a  single  cell.  It  will  heat  the  fila- 
ment of  a  quarter-ampere  tube  for  approximately 
96  hours.  The  four-volt 
A  Battery,  having  two 
cells,  will  light  the  fila- 
ment ofa60-milliampere 
tube  for  200  hours. 

As  you  know,  any 
variation  of  current  in 
the  plate  circuit  pro- 
duces weird  sounds  in 
your  phones.  With  an 
Exide  B  Battery  hooked 
up  to  your  set,  static 
is  the  only  interference 
you  will  have  to  con- 
tend with.  The  Exide  B 
Battery  supplies  steady, 
noiseless  current.  It  permits  the  niceties  of  ad- 
justment that  make  radio  receiving  an  unalloyed 


pleasure.  The  Exide  A  Battery  for  six-volt  tubes 
has  extra-heavy  plates,  assuring  constant  poten- 
tial and  uniform  current  over  a  long  period  of 
discharge.  Like  all  Exide  Batteries,  it  embod- 
ies the  finest  materials 
available. 

In  marine  and 
commercial 
wireless 

Exide  B  Batteries 


give  noiseless,  full-powered 
service  over  a  long  period 
of  discharge.  Designed 
throughout  to  prevent  elec- 
trical leakage.  Capacity,  3 
ampere  hours. 


For  six-volt  tubes 

Like  all  Exide  Storage  Bat- 
teries, the  Exide  A  Battery 
for  six-volt  tubes  is  de- 
pendable and  long-lasting. 
It  is  made  in  four  sizes,  of 
25,  50,  100  and  150  ampere 
hour  capacities. 


On  sea  and  on  land  the 
Exide  plays  an  impor- 
tant role  in  the  indus- 
trial life  of  the  nation. 
In  marine  wireless, 
Exide  Batteries  provide 
an  indispensable  store  of  emergency  current. 
A  majority  of  all  government  and  commercial 
wireless  plants  are  equipped  with  Exides. 

Exide  Radio  Batteries  are  sold  by  radio 
dealers  and  Exide  Service  Stations  everywhere. 
Ask  your  dealer  for  booklets  describing  in  detail 
the  complete  line  of  Exide  Radio  Batteries.  Or 
write  direct  to  us. 


RADIO  BATTERIES 


THE  ELECTRIC  STORAGE  BATTERY  COMPANY,  PHILADELPHIA 

Oldest  and  largest  manufacturers  in  the  world  of  storage  batteries  for  every  purpose 
Service  Stations  Everywhere  Branches  in  Seventeen  Cities 


if  Tested  and  approved  by  Radio  Broadcast  -fc 


Radio  Broadcast 


FIG.  4 


Trouble  with  a  Four-Step  Audio  Amplifier 

/  have  a  four-stage  audio-frequency  amplifier,  the  results 
from  which  have  not  come  up  to  my  expectations.  While 
amplification  on  the  second  and  third  stages  is  quite  satis- 
factory, volume  being  consistent  with  the  number  of  tubes,  and 
the  signals  clear,  there  is  apparently  no  further  amplification 
on  the  last  step,  and  the  set  howls  unmercifully.  Can  you 
suggest  any  way  in  which  this  can  be  remedied? 

L.  B.  L,  Tignal,  Ga. 

THE  writer  of  the  above  encloses  a  diagram  of  his  ap- 
paratus, showing  a  conventional  receiver,  the  output 
of  the  detector  being  impressed  on  a  straight  four- 
stage  amplifier.  L.  B.  L.  uses  common  A  and  B  batteries, 
as  well  as  what  is,  perhaps,  too  many  C  batteries. 

The  ordinary  three-step  amplifier  is  a  precarious  propo- 
sition, to  say  nothing  of  another  additional  stage.  When 
such  an  amplifier  is  built  in  a  single  cabinet,  there  is  almost 
certain  to  be  a  fatal  amount  of  feed-back,  due  to  the 
proximity  of  the  transformers,  wiring,  etc.,  and  the  com- 
paratively dense  magnetic  fields  to  which  the  strong  plate 
currents  in  the  higher  steps  give  rise.  In  order  to  prevent 
howling,  it  is  often  necessary  to  add  an  unusually  high  C 
battery  (the  voltage  applied  under  certain  conditions  to 
the  grid)  which  generally  causes  the  tube  to  be  operated  on 
an  inefficient  portion  of  its  characteristic  curve.  This  will 
tend  to  increase  distortion,  rather  than  reduce  it,  although 
it  is  for  the  purpose  of  reducing  distortion  that  the  C  bat- 
tery is  used. 

Our  correspondent,  and  other  readers  contemplating 
similar  amplifying  apparatus,  are  strongly  advised  to  break 
up  the  amplifier  into  two  sections,  in  individual  cabinets, 
the  first  containing  two  steps  of  amplification  with  ordinary 
amplifying  tubes  to  which  are  applied  plate  voltages  under 
one  hundred  volts.  A  C  battery  should  be  used  in  the 
second  stage  only  when  it  is  justified  by  an  improved  out- 
put. The  second  division  should  comprise  the  "power 
amplifier,"  consisting  of  special  transformers  (if  the  experi- 
menter is  able  to  secure  them),  power  tubes  (five-watt 
bulbs)  and  a  separate  B  battery  up  to  350  volts.  With  such 
plate  voltages,  C  batteries  will  be  necessary,  the  voltage 
of  which,  varying  with  different  tubes  and  plate  potentials, 
must  be  determined  by  experiment.  (The  GRID  does 
not  advise  the  use  of  plate  voltages  in  excess  of  150  volts  on 
other  than  special  power-amplifying  transformers.) 

A  four-step  amplifier  built  in  accordance  with  the  fore- 
going general  instructions  should  give  as  satisfactory  results 
as  may  be  expected  from  such  a  degree  of  intensification. 
However,  The  GRID  does  not  consider  the  fourth  stage 
of  amplification  justified  either  by  results  or  ninety-nine 


per  cent,  of  volume  requirements.  An  ordinary  two-step 
amplifier  will  give  more  than  sufficient  volume  for  horn; 
entertainment,  while  a  third  stage  of  "power"  amplifi- 
cation (a  very  efficient  ready-made  unit  has  been  placed 
on  the  market)  will  further  intensify  the  signals  for  re- 
broadcasting  on  sound  waves  from  an  open  window  or 
veranda. 

Audio  amplification  is  limited,  particularly  when  the 
apparatus  is  constructed  and  operated  by  the  average 
broadcast  enthusiast,  by  distortion,  and  by  the  extraneous 
sounds  which  are  often  amplified  more  efficiently  than  the 
music,  and  which  are  generated  in  each  additional  stage. 

Polarity 

What  is  meant  by  the  positive  and  negative  poles  of  a  battery? 

E.  J.  L.,  Liberty  Hills,  Va. 

PLUS  and  minus,  or  positive  and  negative,  are  merely 
signs  arbitrarily  applied  to  the  poles  of  a  battery  or  to 
electricity  in  any  of  its  many  manifestations,  in  order 
to  name  a  difference  that  does  exist.  In  the  pioneer  days  of 
electricity,  when  man's  insight  into  the  science  was  limited 
to  the  observance  that  when  a  piece  of  flint  glass  and  a  bit 
of  cat's  fur  were  rubbed  together  they  tended  to  attract  one 
another,  it  was  discovered  that  the  electrical  world  was 
divided  into  two  dissimilar  charges.  For  instance,  though 
fur  and  glass  adhered  to  each  other  after  a  brisk  rubbing, 
it  was  found  that  a  second  piece  of  glass,  similarly  electri- 
fied, repelled  the  first  piece  of  glass!  Further  experiments 
added  to  the  puzzle  by  demonstrating  that  while  two  pieces 
of  glass,  electrified  by  friction  with  fur,  repelled  each  other, 
the  fragment  of  glass  thus  charged  was  attracted  to  a  piece 
of  glass  electrified  with  cotton!  In  other  words,  it  became 
apparent  that  there  existed  two  kinds  of  electricity,  which, 
for  want  of  better  words,  were  called  positive  and  negative. 
For  no  particular  reason,  the  piece  of  glass  electrified  by 
fur  was  held  to  have  a  negative  charge,  while  that  electri- 
fied by  cotton  a  positive  charge.  A  great  number  01 
experiments  substantiated  the  theory  of  the  like  charges 
(plus  and  plus,  minus  and  minus)  repelling  each  other, 
and  unlike  charges  (minus  and  plus  which  is  the  same  as 
saying  negative  and  positive)  being  mutually  attractive. 

The  difference  became  more  apparent  and  assumed  a 
practical  significance  in  the  century  that  followed  Franklin 
and  Faraday.  The  two  wires  coming  from  a  cell  were' 
found  to  be  characterized  by  these  same  different  charges, 
and  a  battery  would  build  up  an  accumulative  potential 
only  when  the  individual  cells  were  connected  positive  to 
negative.  Dynamos  were  found  to  possess  similarly 
different  poles,  and  a  relation  was  established  between 


ItADIO  BROADCAST  ADVERTISER 


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This  one  fact  reveals  at  a  glance  the  growth  of 
radio!  3,600,000  RADIOTRONS  already  sold! 
It  was  the  perfection  of  the  RADIOTRON  that 
made  popularization  of  radio  possible — and  every 
vacuum  tube  set  needs  RADIOTRONS  for  clear 
reception  and  amplification—for  sensitivity — 
and  long  distance  reception. 

RADIOTRONS  were  developed  in  the  world's  largest  radio 
laboratories,  where  hundreds  of  modern  radio  achieve- 
ments had  their  beginnings.  There,  they  have  been  steadily 
perfected  to  give  ever  greater  service.  And  now  RADIO- 
TRONS have  been  developed  to  meet  new  needs  of  both 
transmission  and  reception.  When  you  ask  for  a  RADIO- 
TRON, take  a  good  look  to  be  sure  the  name  is  on  it— 
and  the  trade  mark! 

Radio  Corporation  of  America 

Sales  Dept.,  Suite   2066  :  233  Broadway,  New  York 
District  Sales  Offices: 

10  South  LaSalle  Street,  Chicago,  111.  433  California  Street,  San  Francisco,  Cal. 

Radiotrons 


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Radio  Broadcast 


magnets  and  the  polarity  of  wire  carrying  electric  currents. 
Finally,  with  the  advent  of  the  electron  theory  of  matter, 
the  difference  between  positive  and  negative  electricity 
assumed  a  new  significance,  and  science  to-day  declares  the 
universe  to  be  built  up  of  these  unlike  charges,  which, 
arranged  in  different  formations,  are  manifest  as  every- 
thing— gases,  liquids,  and  solids! 

In  a  less  general  field,  it  is  believed  that  a  current  of 
electricity  is  nothing  more  than  a  flow  of  small  negative 
charges,  electrons,  from  negative  to  positive  (away  from 
the  repelling  charge  to  that  which  attracts),  an  action  that 
is  demonstrated  conclusively  in  the  vacuum  tube;  for,  un- 
less the  pole  called  positive  on  the  B  battery  is  connected 
to  the  plate  of  the  audion,  no  current  will  flow  through  the 
tube,  and  the  set  will  be  inoperative. 

We  only  know  that  there  are  two  kinds  of  electricity. 
We  note  the  characteristics  of  each  in  their  relation  to  each 
other  and  to  neutral  charges,  and  call  them  positive  and 
negative. 

Amplifying  Phonograph  Music 

Will  you  kindly  publish  a  diagram  showing  how  a  two-stage 
amplifier  and  a  loud-speaker  may  be  connected  to  a  phono- 
graph? The  idea  is  to  amplify  the  phonograph  music  con- 
siderably, for  lawn  dances,  etc. 

Will  any  other  apparatus  other  than  radio  be  required/1 
W.  H.  J.,  Hilo,  Hawaii. 

TH  E  most  simple  way  to  achieve  what  our  correspond- 
ent desires  is  to  purchase  reproducing  and  amplifying 
apparatus  designed  especially  for  this  purpose.  It 
is  manufactured  by  two  of  the  largest  makers  of  loud- 
speakers, and  has  been  in  the  market  for  several  years.  The 


manufactured  equipment  consists  of  an  especially  designed 
microphone  built  into  a  phonograph  tone-arm,  and  two 
steps  of  power  amplification,  the  first  transformer  of  which 
is  wound  to  take  the  low-voltage  input  from  the  micro- 
phone. 

However,  a  system  almost  equal  to  the  manufactured 
article  can  be  made  up  by  the  radio  fan  almost  entirely 
of  radio  equipment.    The  necessary  parts  are  as  follows: 

One  6-  or  12-volt  microphone  with  a  battery  of  the 
corresponding  voltage.  Trie  transmitter  may  be  of  the 
standard  type,   salvaged  from  a  discarded  telephone. 

One  telephone  induction  coil.  This  may  be  purchased 
new  for  thirty-five  or  fifty  cents,  or,  like  the  microphone,  it 
may  be  removed  from  a  defunct  Bell  instrument. 

Two  sockets,  rheostats,  and  amplifying  tubes. 

One  amplifying  transformer  for  the  second  step. 

Sixty  to  ninety  volts  of  B  battery. 

Loud-speaker. 

One  A  battery,  which  may  also  be  used  to  supply  the 
microphone  current. 

The  circuit  is  shown,  in  Fig.  3,  and  it  will  be  observed 
that,  excepting  that  the  telephone  induction  coil  substi- 
tutes for  the  usual  first-step  amplifying  transformer,  the 
bulb  system  is  the  standard  amplifying  arrangement. 

The  microphone  should  be  placed  where  it  will  pick  up 
the  sounds  emanating  from  the  phonograph,  and  it  is  most 
conveniently  fitted  far  back  in  the  throat  of  the  horn.  A 
more  ingenious  and  satisfactory  method,  which  was  used 
by  The  GRID  for  the  radio  transmission  of  phonograph 
music,  is  to  build  up  an  auxiliary  tone  arm  with  the  micro- 
phone at  the  far  end.  The  opening  should  so  duplicate  the 
standard  tone  arm  that  the  reproducer  may  be  fitted  over 
it  when  it  is  desired  to  amplify  the  records. 


FIG.  5 


NEXT  MONTH 

For  months  we  have  been  looking  for  the  ideal  single  tube  receiver.  In  a  single  evening  in 
August,  using  a  WD-12,  we  heard  two  stations  in  Chicago,  one  in  Pittsburg,  one  in  Boston,  and 
many  nearer  our  testing  station  on  Long  Island.  Photographs,  diagrams,  and  complete  instructions 
next  month. 


What  Would  You  Like  to  Have  in  Radio  Broadcast? 

The  editors  would  be  pleased  to  hear  from  readers  of  the  magazine  on  the  following  (or  other)  topics: 

1.  The  kind  of  article,  or  diagram,  or  explanation,  or  improvement  you  would  like  to  see  in 
Radio  Broadcast. 

2.  What  has  interested  you  most,  and  what  least,  in  the  numbers  you  have  read  so  far. 


RADIO  BROADCAST  ADVERTISER 


e  JCeceiver  c^Jomorrou) 


(^y/ie  Symphon 


Tomorrow  in  Radio  means  a  wider  and 
more  useful  as  well  as  more  entertaining 
broadcasting.  Therefore,  to  the  pur- 
chasers of  receiving  sets,  the  design,  the 
material,  the  workmanship,  the  circuit 
and  the  assembly,  all  play  an  important 
part  in  the  quality  of  reception,  and 
distance  heard. 

The  placing  of  a  Symphony  in  your 
home  is  a  permanent  investment  that 
will  win  your  instant  approval,  and 
occupy  a  prominent  place  among  your 
most  cherished  possessions. 

The  clear  reception  and  unusual  vol- 
ume are  the  results  of  the  high  grade 
units,  the  fine  workmanship,  the  most 


w 

efficient  circuit,  and  the  correct  assembly. 
The  improved  circuit  used  in  the  Sym- 
phony combined  with  the  accuracy  of 
its  construction,  has  increased  the 
selectivity  to  a  marked  degree. 

The  range  of  the  Symphony  Receiver 
is  unlimited.  Recently,  in  Chicago, 
Havana,  Cuba,  was  tuned  in  not  only 
on  a  head  set  but  heard  plainly  on  a 
loud  speaker. 

The  Symphony  Receivers  are  made 
in  two  types — Three  and  Two  stages 
of  audio  frequency  amplification. 

If  your  dealer  cannot  furnish  infor- 
mation on  the  Symphony,  write  for 
illustrated  catalog,  giving  us  his  name. 


JONES  RADIO  COMPANY 

Lytton  Building,  Chicago 

The  Symphony  is  manufactured  under  the  U.  S.  Patent  No.  1113149,  Armstrong  Regenerative  Circuit 

All  parts  used  in  the  Symphony  are  built  and  guaranteed  by  the  Kellogg  Switchboard  &  Supply 
Company  for  twenty-five  years  manufacturers  of  complete  telephone  equipment 


if  Tested  and  approved  by  Radio  Broadcast  ^ 


RADIO  BROADCAST  ADVERTISER 


The  Loud- Speak 
With  the  Natu 

The  Bristol  "Audiophone"  will  bring  into  your  presence  the 
actual  "tonal  personality"  of  the  speaker,  the  singer  or  the 
player.  You  will  hear  them  as  they  are — not  disguised  by 
mechanical  distortion.  The  "Audiophone"  is  a  true  sound 
reproducer,  retaining  all  the  fine  gradations  of  tone  quality, 
volume  and  feeling  which  distinguish  the  original  performance 
of  the  artist.  You  forget  the  instrument,  in  your  enjoyment 
of  the  entertainment  it  brings  to  all  your  household  and  the 
guests  who  may  join  you. 

BRISTOL  + 

TRADE  MARK  ^\ 

AUDIOPHONE 

PATENTS  PENDING,  DESIGN  PATENTS  PENDING 

LOUD-SPEAKER 


Years  of  research  in  sound  reproduction,  in  the  laboratories 
of  an  established  engineering  concern,  have  made  the  "Audio- 
phone" what  it  is — have  given  it  its  round,  full  tone,  its  ample 
carrying  power,  its  distinctive  freedom  from  blurring  and  dis- 
tortion. It  needs  no  separate  storage  battery  for  magnetizing 
current,  and  can  be  used  with  any  two  or  three  stage  power 
amplifiers. 

"AUDIOPHONE  SR."  Complete,  15-inch  bell  $32.50 
"AUDIOPHONE  JR."  Complete,  13-inch  bell  $22.50 

A  new  Bristol  single  stage  power  amplifier  for  use  with  the  usual  tvo 
stage  amplifier  can  be  furnished,  which  will  greatly  increase  the  range 
of  the  Audiophone  where  desirable.    Price  $25.00 

Ask.  your  dealer  to  demonstrate  the  "Audiophone".  IJ 
he  hasn't  it,  write  us — We  will  see  that  you  are  supplied. 


THE  BRISTOL  COMPANY 


WATERBURY, 


CONNECTICUT 


-y&r  Tested  and  approved  by  Radio  Broadcast  -f( 


Radiobroadcast.  May,  1923.  Published  monthly.  Vol.  Ill,  No.  1.  Published  at  Garden  City,  N.  Y.  Subscription  price 
$3.00  a  year.  Entered  at  the  Post  Office  at  Garden  City,  N.  Y.,  as  second  class  mail  matter.  Doubleday,  Page  &  Company, 
Garden  City.  N.  Y. 


RADIO  BROADCAST  ADVERTISER 


Burgess,  the  Radio  Battery 

Specified  by  radio  engineers  — -  designed  and 
built  by  wireless  specialists — and  recommended 
by  leading  manufacturers  of  radio  equipment. 

Burgess  Radio  Batteries,  the  result  of  years  of  careful  experiments 
are  built  under  exacting  manufacturing  standards  which  must  meet 
the  requirements  of  strict  laboratory  formulae  and  tests  —  a  super- 
vision that  insures  their  perfect  operation. 

For  professional  or  amateur  radio  use,  where  noiselessness,  long 
life,  high  capacity  and  uninterrupted,  dependable  service  are  essen- 
tial, Burgess  has  no  superior. 

Burgess  Batteries  are  built  for  both  "A"  and  "B"  circuits.  The 
Burgess  No.  6  is  used  and-  found  most  satisfactory  on  the  "A"  or  fila- 
ment circuits  equipped  with  the  new  type  one  and  one-half  volt 
vacuum  tubes.  The  Burgess- "B"  Battery  is  everywhere  recognized 
as  the  Standard  of  Quality  in  the  wireless  field. 

BURGESS  BATTERY  COMPANY 

Engineers  —  Dry  Batteries  —  Manufacturers 

FLASHLIGHT  —  RADIO  —  IGNITION  —  TELEPHONE 

General  Sales  Office:  Harris  Trust  Bldg.,  Chicago 
Laboratories  and  Works:  Madison,  Wisconsin 

Branches  : 

New  York    Boston    Washington    St.  Paul    Kansas  City    New  Orleans 


In  Canada:. BURGESS  BATTERIES,  Ltd. 
Winnipeg,  Toronto,  Montreal 


BURGESS 

RADIO  BATTERIES 

"ASK  ANY  RADIO  ENGINEER" 


£ 


if  Tested  and  approved  by  Radio  Broadcast  -Jc 


RADIO  BROADCAST  ADVERTISER 


1 

I 


Dependable 
Radio 

Sets  s&  Service 

Can  always  be  had  from  local  dealers 
who  have  been  honored  with  the 

M.R.C.FRANCHISE 


For  Three  Reasons: 


1: 

2: 
S: 


Franchise  is  granted  only  to  mer- 
chants of  standing  and  financial  re- 
sponsibility, with  sufficient  technical 
experience  to  render  intelligent  service. 

"Michigan"  Radio  Sets  are  the  finest 
examples  of  correct  Regenerative  radio 
engineering,  expressed  in  superlatively 
good  workmanship. 

The  Michigan  Guarantee  is  as  valid 
as  a  Bond.  For  back  of  it  stands  the 
strongest  independent  Radio  manufac- 
turing concern  in  the  United  States. 


"SENIOR"  SET 


M.  R.  C.  Regenerative 
Receiving  Sets 

are  built  under  Armstrong  License  (U.  S.  Pat.  1 , 1  1  3, 1 49  and  letters 
patent  No.  607,388).  This  means  that  they  embody  the  latest  devel- 
opment in  Regeneration — the  soul  of  radio. 

Long  Distance  Wonder  Workers 

The  "Senior  Set"  includes  both  detector 
and  amplification,  and  can  be  used  with 
either  headphones  or  loud  speakers  or  both. 

The  "Junior  Set",  a  detector  unit  only,  is 
limited  to  headphone  reception.  It  can  how- 
ever, be  hooked  up  with  the  Michigan  Am- 
plifier unit  for  loudspeaker  reception. 

Send  for  the  M.  R.  C.  Circular,  giving  full 
information^on  both  sets  and  parts,  and  tell- 
ing of  some  of  the  long-distance  triumphs 
"JUNIOR"  SET  of  M.  R.  C.  set  owners. 


Grand  Rapids, Michigan 


if  Tested  and  approved  by  Radio  Broadcast  jc 


RADIO  BROADCAST  ADVERTISER 


General  Radio  Type 
300  Amplifier  Unit — 

Works  equally  well  with 
crystal  or  tube  detectors. 
Is  a  compact  unit,  wired 
ready  for  external  connec' 
tions.  Two  or  more  units 
may  be  used  together  to 
obtain  multi-stage  ampli- 
fication. 

Prices 

Type  300-A  Amplifier  Unit 
for  WD-11  Tubes,  complete 
except  for  tube  and  barteries, 
$7.50 

Type  3C0-B  Amplifier  Unit, 
for  standard  6  Volt  Tubes, 
$8.00 


Type  231-A  Transformer 

— Qives  the  maximum 
amplification  possible- 
without  distortion.  Like 
all  Amplifying  Trans- 
formers manufactured  by 
The  Qeneral  Radio  Com- 
pany, the  Type  231-A  is 
guaranteed. 

Price  $5.00 


General  Radio  Type  214 
Rheostat— 

A  convenient,  practical  in- 
strument, equally  well  adap- 
ted for  experimental  service 
or  permanent  installations. 
You'll  never  cause  unpleas- 
ant noises  in  the  phones 
when  vou  rotate  the  contact 
arm  of  a  Type  214  Rheostat. 

Price 

For  the  new  UV201-A Tubes, 
20  Ohms. 

For  the  newer  UV199  Tubes, 
50  Ohms. 

For  the  Standard  Tube,  7 
Ohms. 

$2.25 

Type  214  Potentiometer— 

To  get  your  gas  detector  on 
that  sensitive  kink  by  fine  ad- 
justment of  the  plate  poten- 
tial, use  this  General  Radio 
400  Ohm  Potentiometer.  It 
will  control  regeneration  in 
your  radio  frequency  ampli- 
fier by  a  positive  grid  bias. 
Price  $3.00 

Amateurs — 

Bring  your  problems  to  us. 
Our  Engineering  Staff  is  al- 
ways at  your  disposal. 


For  more  than  eight  years,  among  men  who 
know  and  use  Radio  Apparatus  of  the  better 
sort,  the  name — General  Radio  Company 
— has  been  accepted  as  a  guarantee  of  all  that  goes 
to  make  up  satisfaction  and  as  synonymous  with 
the  advances  in  theory  and  practice  which  accom- 
pany all  true  Radio  progress. 

As  an  example — for  the  amateur  who  wants  real 
Radio  efficiency — there  is  no  single  piece  of  appa- 
ratus which  more  completely  fills  its  niche  than 
the  General  RadioType  300-A  Amplifying  Unit — 
the  Amplifying  Unit  which  requires  no  storage 
battery. 

If  you  are  interested  in  Radio  Apparatus  in  which 
price  is  subordinated  to  satisfaction,  send  for 
Bulletin  914  B.  It  is  an  educational  pamphlet  for 
the  amateur  who  wants  better  equipment. 

GENERAL  RADIO  CO. 

Manufacturers  of 

Radio  and  Electrical  Laboratory  Apparatus 
11  Windsor  Street  Cambridge,  Mass. 

5169 


Vk"  Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


A  high  quality  1000-meter 
tuning  coil  for  $3.1 


HERE'S  as  fine  a  tuning  coil  as  you 
ever  saw  at  a  price  that  insures 
tremendous  value.  Made  in  such  large 
quantities  that  price  is  no  index  of  its 
quality.  Mahogany-finished  hardwood 
ends,  nickel-plated  metal  parts,  silk- 
covered  wire  on  seamless  tube. 
Double  slides  insure  clear,  sharp  tun- 
ing. Order  one  from  your  dealer. 

FROST- RADIO 

The  complete  Frost  Radio  line  of  Frost 
Fones,  Plugs,  Jacks,  Jac-Box,  Microphones, 
Tuning  Coils,  Receiving  Transformers, 
Extension  Cords,  offers 
radio  users  the  highest 
quality  apparatus  at 
quantity  -  production 
prices.  Another 
example  of 
Frost  Radio  , 
value  is  the  Frost  Radio  Recejv- 

.   .      _  ing  1  ransformerIMo.400 

No.  400  Receiving  Trans- 
former shown  here.  Mahogany-finished  hard- 
wood base  and  ends;  polished  nickel-plated 
metal  parts.  200  to  4000  meter  range.  Silk- 
covered  wire  wound.  See  it  at  your  dealer's. 
Retail  price:  $8.50. 


50 


The  dealer 
who  sells 
Frost  Radio 
is  a  good  man 
to  know.  He 
gu  ar  a  n  tees 
Frost  mer- 
chandise  be- 
cause  he 
knows  it  is 
right.  See 
him  today. 


"Like 

Postage-Stamps 


The  same 
fine  quality 
which  has 
made  F  rost 
Fones  the 
world's  fast- 
est-selling 
headset  is 
back  of  every 
Frost  piece  of 
Radio  appar- 
atus. 


Used 

Everywhere" 


HHBBRI  EFROSXinc. 

154  WEST  LAKE  STREET,  CHiaGOJLUNOIS/ 


f  Recharge 
Your  Battery  at  Home 

Charges  Both  A  and  B  Radio  Batteries 

Don't  be  without  the  use  of  your  Radio  Receiving 
Set  while  your  battery  is  being  charged.  Get  a 
Valley  Charger  and  charge  your  battery  right  at  home. 

Attach  the  Charger  to  your  home  lamp  socket- 
attach  the  clips  to  the  battery  terminals  and  you 
will  get  a  quick,  tapering  charge  which  just 
exactly  charges  your  battery,  but  cannot  over- 
charge or  harm  it  in  any  way. 

Will  charge  thb  A  6  volt  battery  at  a  5  ampere 
rate,  and  the  B  22f£  volt  battery  at  the  required 
V%  ampere  rate.  45  volt  B  batteries  may  be  con- 
nected in  parallel  bo  that  they  can  also  be  charged. 

SATISFACTION  GUARANTEED  If  your  local 
distributor  cannot  supply  you,   write  direct  to 

VALLEY  ELECTRIC  COMPANY, 

artment    G  ST.  LOUIS,  MO. 


$18.00 

F.  0. 6.  St.  Louis 


FREE  Radio  Catalog 


Our  big  stock  of  standard  makes  of 
radio  sets,  parts  and  supplies,  fully 
illustrated.  Playsafe — buystandard 
equipment  from  a  reliable  house. 
We  ship  from  stock. 
Send  $5.00  for  Murdock  Loud 
Speaker,  including  fibre  horn,  stand 
and  adjustable   phone   unit.  Re- 


quires no  battery. 


Julius  Andrae  &  Sons  Co. 

In  Business  Since  1860 

112  Michigan  St.  Milwaukee.Wis. 


Weston  it 
Filament 
Voltmeter 

Makes  it  possible  to 
prevent  premature 
tube  burn-outs — fa- 
cilitates exact  turn- 
ing— duplicates  results 
instantly. 
Write  for  Circular  J 

Weston  Electric  Instrument  Co. 

179  Weston  Avenue  NEWARK,  N.  J 


•jr  Tested  and  approved  by  Radio  Broadcast  -jr 


RADIO  BROADCAST  ADVERTISER 


Tr if  the  Bmdtosiot 
OAKwr  Radio  SeUo-n^d 


o4        T/in7/  ^w/fe  Ybw/ 


TV*//  in  those  distant  stations  that 
you  lose  with  Wire  Rheostats 

Does  your  receiving  range  enable  you  to  pick 
up  concerts  over  great  distances?  If  not,  try 
the  Bradleystat. 

Read  this  interesting  letter  from  Chas.  H. 
M.  White  of  Massachusetts  Institute  of 
Technology   at  Cambridge,  Massachusetts: 

/  have  tried  the  Bradleyslat  on  my  radio 
set.  The  improvement  is  really  remarkable 
and  beyond  all  my  expectations.  Previously 
I  only  picked  up  local  stations  and  WJZ, 
but  on  my  first  trial  with  the  Bradleyslat 
I  heard  KYW  {Chicago), WOC  (.Daven- 
port)  and  many  other  stations." 

Jet  the  Bradleystat,  today,  from  your  nearest 
radio  dealer  and  get  more  enjoyment  from  your 
radio  set.  Insist  on  the  genuine  Bradleystat. 


Electric  Controlling  Apparatus 
278  Greenfield  Avenue  •  Milwaukee,  Wisconsin 

Member  of  the  National  Radio  Chamber  of  Commerce 


Retail  Price 

$1.85 

P.P.  10 c  extra 


REGISTERED 

PERFECT  F 


MENT  CONTROL 


Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


Steady,  Full-powered  Batteries 

EVERY  radio  set  has  its  own  peculiarities — little  nice- 
ties of  adjustment  at  which  best  results  are  obtained. 
Battery  voltage  and  amperage  must  be  just  so.  And 
once  adjusted,  current  must  have  sustained  evenness 
and  steadiness. 

Get  good  batteries.  They're  the  most  satisfactory  and 
economical  in  the  end.  Westinghouse  Radio  Storage  Bat- 
teries will  settle  the  problem  practically  for  good.  They  last 
indefinitely  and  are  easily  and  repeatedly  rechargeable. 
Built  by  Westinghouse — you  know  they're  RIGHT. 

Westinghcuse  "  A "  Batteries  are 

carefully  constructed,  full-capacity,  slow- 
discharge,  long-life  batteries.  Made  in 
4,  6,  and  8-volt  sizes  with  5,  9,  and  13 
plates  per  cell,  to  meet  the  various  fila- 
ment-battery requirements. 

Westinghouse  "B"  Batteries.  The 

Westinghouse  22-M  G-2  (22  volts)  is  a 
marvel  for  steady,  noiseless,  full-powered 
service.  Glass  case;  visible  interior; 
sealed-in  tops.  Larger  types,  too?  also 
2-volt  single  cells  for  "C"  batteries. 


At  radio  dealers  and  Westinghouse 
Battery  Service  Stations  everywhere. 
Write  for  illustrated  folder,  "JFest- 
inghouse  Radio  Storage  Batteries." 

WESTINGHOUSE  UNION  BATTERY  CO 

WESTINGHOUSE 


RADIO 
"A"  "//••  and  "C" 

BATTERIES 


NOVO* 

"B"  BATTERIES 


NOTE  THE  INSULATED  BINDING 
POSTS  AND  7in.  WIRE  CONNECTOR 


NOVO      MT'G  CO. 


^424  W.  33^  ST, 
NEW  YORK 


531  SO,  DEARBORN  ST. 
CHICAGO 


Super-Sensitiveness  f 

'T'HHcrystal  is  the  "bull's-eye" 
of  your  crystal  receiving  set. 
Unless  it  is  super-sensitive  you 
are  wasting  time  and  entertain- 
ment and  cannot  "hit"  the  com- 
bination for  best  results.  Insist 
upon  the  genuine  original  Arling- 
ton Tested  NAA  Detector  Minerals. 
They  are  carefully  selected  from  bulk 
stock,  individually  tested  and  guaranteed 
SUpet-sensitive. 

Galena,  Silicon  or  Goldite  price  per 
Crystal,  25c.  Samemounted  in  brass  cup, 
40c.  Obtainable  at  your  dealer's  or  sent 
direct  (post-paid)  on  receipt  of  price* 


Newman-Stern  Building 


Cleveland 


RADIO  "A"  &  "B"  STORAGE  Batteries  CHARGED  at  Home  For  a  Few  Cents  Overnight  with 
"The  PATENTED  FULL  WAVE"  100-130  Volts  60  Cycle  A.  C.  Magnetic  Taper  Charge  Design 


All  Types  But  "B" 
Charge 
AUTO 
Batteries 
Overnight 
Right  in 
Your  CAR 


F-F  RADIO  RECTIFIER; 


CHARGES 
RADIO  &  AUTO  BATTERIES 


Eventually  You  Will  Buy  An  F-F  REC- 
TIFIER. Why  Not  Now?    The  Sooner 
You  Buy  It;  The  More  You  Save.A-B 
Charges  6  Volt  "A"  &  Auto:  &up  to  120Volts  Of  "B"  &  Loud  Speaker  Storage  Batteries  In  Series  Induc- 
tively At  Home  Overnight;  Disconnecting  &  Multiple  Connections  Unnecessary.  Charging  Circuits 
Separate.  No  Chance  For  Grounds  Or  Short  Circuits.  Nothing  To  Slop  Over,  Be  Filled,  Burn  Out.  Need 
Attention  Or  Cause  Trouble.     Infusible  Rectifying  Brushes  Maintain  Constant  Efficiency  Uninter- 
ruptedly.  Complete  Portable  Automatic.    No  Skill  Required.    AMMETER  Eliminates  Guess  Work. 
Nothing  Like  It  Made.  LastsLifetime.  Screw  Plug  In  Lamp  Socket;  Snap  CLIPSOnBattery  Terminals; 
TurnSwitch&BatterylsChargedln  Morning.  Charged  Batteries  Mean  Fewer  Expensive  Replacements. 
It  Costs  Less  To  Buy  An  F-F  RECTIFIER  than  To  Be  Without  One.  INSIST  on  The  F-F  RECTIFIER 
Bult  By  A  Master  Of  The  Art  in  7  TYPES.  Thousands  Sold  Make  Possible  These  POPULAR  PRICES. 
Type  6charges'-A"6VoltBattery  At  6  amperes  $15    Type  12  charges  12  Volt  Battery  At  5  amperes  SIS 
TypeB  chargesRadio -  -B"Batterie»Upto  1 20Volts  $15  Type  A-B  is  CombinationOf  Types  6  &  Bj$20 
Type  1 66  charges6  Volt  Battery  At  1 2  amps  $20  Type  1612  charges  1 2  Volt  Battery  At  7  amps  $20 
Type  1626  is  a  Combination  of  Types  166&  1612andCharges  Both  6  &  12  VoltBatteries  $28 
The  3  Lower  Types  are  recommended  for  heavy  Batteries,  or  where  time  is  limited. 
SHIPPING  WEIGHTS  Complete  with  AMMETER  &  BATTERY  CLIPS  11  to  15  lbs. 
Purchase  from  DEALER,  or  Mail  Check  for  Prompt  Shipment.    Include  Postage  and 
Insurance  Charges  for  P.  P.  Shipment,  or  Write  us  to  Ship  Type  desired  C.  0.  D. 
Order  Now,  or  WRITE  Immediately  for  FREE  Descriptive  BOOSTER  Bulletins  41  St  41A. 
FRANCE  MFG.  CO.,  CLEVELAND,  OHIO.  U.  S.  A. 


■j^-  Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


<Md< 


55 


THE  HIT  OF  THE  RADIO  WORLD 

For  Sale  by  Good  Dealers  Everywhere 

Free  Catalogue  on  request  to  Dealer  or  Consumer 

CROSLEY  MANUFACTURING  COMPANY 


■#4  tube 
frequency  Set 


S20  ALFRED  ST. 


CINCINNATI,  OHIO 


20 


Licensed 
underflrmstrong 


^generativecReceiver  Set 


0 

<§)> 


US.%tenMoM13J4<r^ 

The  trade  name  "Crosley"  is  used  by  permission  of  the  Crosley  Manufacturing  Company 

Write  for  Free  Catalogue 

THE  PRECISION  EQUIPMENT  CO. 

^Vowel  Crosley  Jr.Tresident 


S20  GILBERT  AVE. 


CINCINNATI,  OHIO 


Tested  and  approved  by  Radio  Broadcast  -fc 


RADIO  BROADCAST  ADVERTISER 


PRICE  $40.00 
REGENERATIVE  RECEIVER  ^ 

A  REAL  BROADCAST  RECEIVER 

Licensed  Under  Armstrong  U.  S.  Patent  No.  1113149. 

For  amateur  use  only.  

Write  for  Catalogue  No.  7  of  New  Chelsea  Radio 
Equipment. 

CHELSEA  RADIO  CO. 

152  5th  St.,  Chelsea,  Mass. 


Determines 
RANGE 
OF 
YOUR  SET 

$1 

Complete 


The  McNeary 


Determines 
DISTANCE  OF 
CALLS 
RECEIVED 

$1 

Complete 


Radio  Scalometer 


and  Official  Radio  Map 


After  you  recover  from  the  thrill  you  get 
every  time  you  tune  in  on  an  out-of-town 
station,  the  first  thing  you  want  to  know  is 
HOW  FAR  was  that? 

With  the  Scalometer  mounted  on  the  offi- 
cial map  you  read  the  distance  directly  on 
the  tape — instantly  and  correctly. 


SCALOMETER 

An  instrument 
of  precision  in  a 
beautifully  finish- 
ed aluminum  case. 


RADIO  MAP 

Authoritative,  up- 
to-the-minute  .show- 
ing' .  broadcasting' 
stations,  time  zones, 
radio  districts,  cities 
and  towns  of  the 
United  States  and 
Canada. 


If  your  dealer  cannot  supply  you,  s 
EMBLEM  MANUFACTURING 


BROADCAST 
DIRECTORY 

In  handy  book- 
let form  with  all 
broadcasting  sta- 
tions alphabetical- 
ly arranged  by 
call  letters. 
nd  one  dollar  to 


CORPORATION 
253  Middle  City  Bldg.,  Philadelphia,  Pa. 


Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


THE  Federal  Telephone  and  Telegraph  Company  of  Buffalo  is  a 
large  factor  in  the  radio  industry  and  has  an  excellent  reputa- 
tion for  the  quality  of  its  product. 

It  is  a  very  extensive  user  of  Formica  insulation  not  only  in  the 
complete  sets  which  it  produces  but  in  the  radio  parts,  variometers, 
variocouplers,  head  sets  of  which  it  is  a  large  manufacturer. 

A  list  of  the  users  of  Formica  reads  like  a  directory  of  the  leading 
independent  radio  manufacturers.  So  many  of  the  best  informed 
radio  men  in  America  cannot  be  mistaken  in  their  opinion  that  For- 
mica is  most  uniform,  the  best  looking,  and  the  most  efficient  radio 
insulation. 

Dealers  and  amateurs  can  safely  follow  these 
great  concerns  in  selling  or  using  Formica. 


THE  FORMICA  INSULATION  COMPANY 

4628  Spring  Grove  Avenue 
Cincinnati,  O. 


50  Church  St.,  New  York,  N.  Y. 
422  First  Ave.,  Pittsburg,  Pa. 
1042  Granite  Bldg.,  Rochester,  N.  Y. 
415  Ohio  Bldg.,  Toledo,  Ohio 


SALES  OFFICES 
1210  Arch  St.,  Philadelphia,  Pa. 
1819  Lyndale  Ave.,  S.  Minneapolis,  Minn. 
Sheldon  Bldg.,  San  Francisco,  Calif. 
Whitney  Central  Bldg.,  New  Orleans 


414  Finance  Bldg.,  Cleveland,  Ohio 
9  S.  Clinton  St.,  Chicago,  111. 
313  Title  Bldg.,  Baltimore,  Md. 
47  King  St.,  Toronto,  Ontario 


ORMICA 

Made  from  Anhydrous  Redmanol  Resins 
SHEETS    TUBES  RODS 


•fc  Tested  and  approved  by  Radio  Broadcast  ■fa 


RADIO  BROADCAST  ADVERTISER 


,uNowYbrks  Leading  "Radio  House" 


THE  SYMBOL  OF  SERVICE 


TRANSFORMERS 


Model  UV-712    ,;/,-/    Model  UV-1714 

"Audio  Frequency"  "Radio  Frequency" 


Model  UV-712  and  UV-1714  two  trans- 
formers designed  especially  by  the  Radio 
Corporation  for  their  detector  tubes 
UV-200  and  UV-201. 
Important   features — Ranges  may  be 
doubled  or  tripled. 
Distortion  greatly  reduced. 
Selectivity  greatly  increased. 
Vacuum  tube  noises  practically  elim- 
inated. 

Further  information  on  request. 

"Modem  Radio" — a  two  hundred  and  eight  page  catalogue  of  our 
Radio  supplies ,  equipment  and  apparatus  sent  for  twenty-five  cents. 

2031-Q 

CONTINENTAL  RADIO  AND  ELECTRIC  CORPN. 


HODELX       •  RANGE 
UV-1714  200-500 
500-5000 

RADIO  TRANSFORMER 

MFGO  FOP.  R.C.A  BY  G.£.C0.,U.S.A. 


6  AND  15  WARREN  ST. 


NEW  YORK,  U.  S.  A. 


and  burned  out  bulbs  are 
much  alike.  The  time 
to  attend  to  them  is  be- 
fore they  happen.  Care 
is  the  best  safeguard 
for  the  milk;  and  the 

RADECO 

SAFETY  FUSE 

(Patent  Pending) 

is  the  only  absolute  and 
positive  means  of  protect- 
ing the  tube. 

The  RADECO  Safety  Fuse 
fits  directly  on  the  filament 
terminals  where  no  excess 
current,  even  an  accidental 
short  from  faulty  wiring 
can  possibly  get  by.  It  fits 
any  standard  tube  used  in 
any  standard  socket  and 
does  not  affect  the  efficiency 
of  your  set. 

4  in  standard  package  $1.00 
For  WD11,  50  cents  For  WD12,  50  cents 

For  201A,  50  cents 
For  other  tubes,  4  for  $1.00 

Different  tubes  require  different  capacity  fuses.    State  what 
tube  fuses  are  for. 

Radio  Equipment  Co. 

630  Washington  St.  Boston,  Mass. 
-New  England's  Oldest  Exclusive  Radio  Housez 


RADIO 

'"■*f6r-*a1l'.' 


The  Big  Book  on  Radio, 
covers  eveything — 
theory,  operation  and 
construction  of  radio 
apparatus,  with  new 
popular  features.  150 
drawings,  diagrams  and 
photographs. 


By  H.GERNSBACK 

EDITOR -RADIO  NEWS 


At  all  Bookstores,  $2.00 

or  postpaid  for  $2.10.    Write  for  circular  B. 

J.  B.  LIPPINCOTT  CO. 

226  S.  Sixth  Street  Philadelphia,  Pa. 


•fa  Tested  and  approved  by  Radio  Broadcast  jr 


RADIO  BROADCAST  ADVERTISER 


,?oprano  Solos 

\The  Stock.  Exchange 

When  you  try  to  tune  in  with  a  single  circuit  receiver, 
it  is  not  surprising  that  songs  should  suddenly  turn  into 
market  quotations  and  bedtime  stories  into  weather  reports. 

For  with  several  hundred  powerful  broadcasting  stations  all  oper- 
ating on  one  narrow  wave  band,  it  takes  real  selectivity  and  sensi- 
tivity to  get  a  satisfactory  radio  programme. 

Get  a  Paragon  three-circuit  receiver.  Then  you  will  have  the 
pleasure  and  satisfaction  of  obtaining  the  station  you  want  when 
you  want  it.  Clear,  complete  programmes  without  interruption  or 
disturbance. 

Ask  some  experienced  amateur  what  he  knows  about 

PARAGON 


Reg.  U.  S.  Pat.  Off. 


RADIO  PRODUCTS  * 


The  amateur  will  tell  you  that  the 
Paragon  three-circuit  receiver,  because 
of  its  great  superior  selectivity  and 
sensitivity,  can  pick  and  choose  be- 
tween broadcasting  stations  of  about 
the  same  signal  strength  with  less  than 
one  per  cent  differential. 

This  means  that  with  a  Paragon  re- 
ceiver you  get  what  you  want  when  you 
want  it — complete  messages  and  clear 
music  from  the  station  you  tune  in  on, 
without  interruption  and  jamming. 
Until  you  have  listened  in  with  a 
Paragon  three-circuit  receiver,  you 
cannot  guess  the  real  pleasure  and  fas- 
cination of  radio. 


Also  Manufacturers  of  PARAGON 


Radio  Telephone 

Transmitters 
V.  T.  Control  Units 
Rheostats 
Potentiometers 
V.  T.  Sockets 
Detectors 


Amplifier 

Transformers 
Control  Dials 
Amplifiers 
Receivers 
Switches 
Variometers 


Long  before  broadcasting  popular- 
ized radio  with  the  general  public, 
Paragon  equipment  was  the  choice  of  the 
experienced  amateur.  He  will  tell  you 
today  that  if  you  want  quality  and  satis- 
faction, Paragon  Radio  Products  are 
the  best  and  safest  buy  on  the  market. 

An  illustrated  Catalog  of  Paragon 
Radio  Products  Is  Yours  For  the  Asking 

DEALERS — The  Adams-Morgan  Company 
has  an  interesting  proposition  to  make  to  rep- 
utable radio  dealers  who  believe  in  quality 
merchandise.  Details  on  request. 

ADAMS-MORGAN  COMPANY 
10  Alvin  Ave.,  Upper  Montclair,  N.  J, 


Type  RTJ-5    Regenerative  Receiver 

and  Detector — $75.00 
Type  A-2  Two-Stage  Amplifier-Sso. 00 
(Licensed  under  Armstrong  Patents.) 


-jfc-  Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


Thrills  III 


Thrills  never  end  when  you 
have  a  Tuska  Popular — the 
regenerative  receiving  set 
that  experts  recommend. 
Signals  clear  and  sharp  come 
in  night  after  night  from 
far-away  stations.  And  for 
nearby  programs,  plenty  of 
volume  without  distortion. 
Every  part  Tuska-made ; 
known  for  12  years  as  fine 
radio  instruments. 

The  C.  D.  TUSK  A  Co. 

Hartford,  Conn. 


Tuska  Popular  No.  225 

Regenerative  Receiv- 
ing Set,  Tuska  receiver, 
detector  and  2-stage 
amplifier,  licensed  un- 
der Armstrong  U.  S. 
Patent  No.  1,113,149. 
Catalogue  No.  13-A, 
showing  Popular  and 
other  sets,  on  request. 


And  Feel  the  Difference,  Too! 

YOUR  RADIO  fan  wears  his  head  set  several 
hours  at  a  time.  He  probably  bought  it 
because  the  dealer  let  him  "listen  to  the 
difference,"  and  he  very  quickly  learned  the 
character  of  the  true  musical  toneC  I  Cgave  him, 
because  of  its  non-metallic  diaphragm.  He  learn- 
ed something  more,  however,  after  several  hours' 
use.  The  big,  comfortable  caps  covering  the  en- 
tire ear — the  broad,  well  fitting  aluminum  band 
— they  soon  showed  him  that  C  I  C  not  only 
means  beauty  of  tone.  It  means  also  "Solid 
Comfort."    Point  this  out  to  your  trade,  too! 

CONNECTICUT  INSTRUMENT  CO. 

Stamford  Connecticut 


FREE  HAND  BOOK  OF 
RADIO  HOOKUPS 

We  will  send  you  free  a  useful  Hand  book  con- 
taining 25  easily  understood  diagrams  of  tested 
radio  hookups.   Just  enclose.2c.  stamp  for  postage. 

We  will  appreciate  it  as  a  favor  if  you  will 
mention  the  name  and  address  of  the  radio  dealer 
with  whom  you  prefer  to  trade,  and  whether 
he  now  carries  All-American  Audio-  and  Radio 
Amplifying  Transformers. 

^EsS&A^     200  No.  Jefferson  IStCticaqft  III  '*»!> 


ItEARItRADIOl 

f 

I  Tr 

Le 

Be  a  Radio  Expert 


Here'syour  opportunity.  Radio  needs 
you.  Win  success  in  tnis  fascinating  held. 

Trained  men  in  demand  at  highest  salaries. 

Learn  at  home,  in  your  spare  time. 


I  will  train  you,  quickly  and  easily,  to  design, 

construct,  install  operate,  repair,  maintain  and  sell 
all  forms  of  Radio  apparatus-  My  new  methods  are  the 
most  successful  in  existence.    Learn  to  earn. 

$1,800  to  $10,000  a  Year 

F  R  F  F  Wonderfull  home-construction,  tube 
1  J-*  J-i      receiving    set,   of    latest  design. 

Write  for  *'KaOio  Facte**  free.     Engineer  Mohaupt. 

American  Electrical  Association 
Dept.  B5  4513  Raventmood  Ave. ..Chicago 


^  Tested  and  approved  by  Radio  Broadcast  ^ 


RADIO  BROADCAST  ADVERTISER 


for  the  new 

M  U  R  D  O  C  K 

Loudspeaker 

Never  before  have  you  been  able  to  get  so  good 
a  Loudspeaker  for  such  a  low  price. 

Complete  with  our  new  Loudspeaker  phone  unit, 
fibre  horn,  aluminum  tone  chamber  and  molded 
base. 

You  do  not  need  extra  batteries  to  use  the 
Murdock  Loudspeaker.  It  works  splendidly  with 
amplification.    Do  not  use  on  a  crystal  set. 

For  18  years  Murdock  Headphones  have  been 
leaders  in  their  field.  Huge  production  has  made 
it  possible  to  sell  this  quality  product  at  a  low 
price— 2000  ohms  $5.00;  3000  ohms  $5.50. 

Now  the  new  Murdock  Loudspeaker  is  becoming 
a  real  sensation  in  the  Radio  field — another  quality 
product  at  an  unheard  of  price. 

Get  one  of  these  new  Loudspeakers  from  your 
dealer.    Be  sure  it's  a  Murdock. 

If  your  dealer  cannot  supply  you  with  either 
Murdock  Headphones  or  a  Murdock  Loudspeaker, 
send  your  order  and  dealer's  name  direct  to  us. 

WM.  J.  MURDOCK  COMPANY 

General  Offices  and  Factory 

341  Washington  Avenue,  Chelsea,  Mass. 


(Sales  offices) 
New  York       San  Francisco  Chicago 
Los  Angeles  Seattle 


STANDARD  APPARATUS  SINCE  1904 


Tested  and  approved  by  Radio  Broadcast  ^ 


RADIO  BROADCAST  ADVERTISER 


MIRACO  GETS  'EM  1500  MILES  AWAY 

Users  of  the  MIRACO  Radio  Frequency  Broadcast  Receiver  report  wonderful  results.  St. 
Louis  hears  Schenectady — Davenport  hears  Newark — Cincinnati  hears  San  Francisco. 

Reception  is  clear  and  distinct,  tuning  is  very  sharp,  and  there's  practically  no  inter- 
ference. 

MIRACO  sets  may  be  used  with  either  WD  11  tubes  and  1|  volt  dry  cell  or  6  volt  tubes  and 
6  volt  storage  battery. 

Order  your  MIRACO  set  TO-DAY  and  be  sure  to  specify  tubes  to  be  used. 


Retail  Price  $54.50 

DEALERS 

When  you  get  our  prop- 
osition in  detail — you'll 
WANT  TO  PUSH 
THE  MIRACO  LINE. 


AGENTS 

Wanted  Everywhere. 


THE  MIDWEST  RADIO  COMPANY 


806  Main  Street,  Cincinnati,  Ohio 


•  •  • 


•  ••• 


1 


RADIO  PROTECTOR  I 


SOLDERALL  > 

The  Only  Convenient  Metal  Solder 

Every  Electrical  Connection 

Needs  SOLDERALL 
For  Perfect  Reception 


AT  JOBBERS  © 
AND  DEALERS  OR  BY  MAIL  @ 

254ATUBE  m 

L.S.BRACH  MFG.  CO.  ■ 

NEWARK,  N.  tj.  9 

a  mm*  a  nsa  mm  »#  nil 


"BUILD  YOUR  OWN' 
With  "RAbCO"  Parts! 

If  you  need  small  radio  parts 
in  a  rush,  "EASCO"  will 
supply  them  cheaper,  better 
and  quicker  than  any  one. 
Be  sure  to  get  our  great  68- 
pagecatalog.  Over  500  differ- 
ent parts,  300  illustrations. 
This  catalog  contains  75 
Vacuum  Tube  Hook-Ups,  all 
values  being  shown.  Due  to 
great  cost,  catalog  sent  only 
upon  receipt  of  15c,  stamps 
or  coin. 

Radio  Specialty  Co.,  Inc. 

10Z  Park  Place.  New  York 


The  FRENCH  "BINDERS 

Good  books  with  artistic  binding 


COUNTS.  T  LIFE  PRESS 


GARDEN  CITY,  N.  Y. 


FREE 


to  Oar  Owners.  Garagemen, 
Mechanics.  Send  TO-DAY  for 
FREE  COPY  of  the  American 
Automobile  Digest.  Contains  helpful,  instructive 
information  on  overhauling,  ignition,  carburetors, 
storage  batteries,  wiring  adjusting,  repairing,  etc. 
Profusely  illustrated. 

American  Automobile  Digest,  669  Butler  Bldg.,  Cincinnati,  O. 


yir;  Tested  and  approved  by  Radio  Broadcast  -fa 


RADIO  BROADCAST  ADVERTISER 


The  Secret  of  Its  Efficiency 

It  is  a  well-known  fact  that  losses  in  radio  condensers  take  place  in  the 
solid  insulating  material  used  in  their  construction. 

And  it  is  equally  true  that  a  condenser  increases  in  efficiency  of  signal 
reproduction  as  its  losses  decrease. 

The  Connecticut  Variable  Condenser  not  only  employs  the  two  best 
insulating  materials  known — mica  and  hard  rubber — but  the  smallest 
possible  amount  of  each.  This,  then,  is  the  reason  for  its  extremely  low 
resistance—  0.2  ohm— as  well  also  the  secret  of  its  high  efficiency  at  short 
wave  lengths. 

Descriptive  bulletin  100-E  upon  request 


CONNECTICUT  JSKSSS  COMPANY  (Q) 

MERIDEN  RADIO  DIVISION  CONNECTICUT 


RADIO  BROADCAST  ADVERTISER 


"These  phones  sure  have 
a  mellow  tone" 


You  Can  Get  BASCO  Phones 
Despite  Demand 

NO  NEED  for  accepting  substitutes.  Every 
possible  measure  is  being  taken  by  the  manu- 
facturers of  BASCO  Phones  to  keep  up  to  the 
demand  —  and  it's  being  done  without  slighting  me- 
chanical exactness.  Close  inspection  guards  BASCO 
Phone  quality  irrespective  of  demand.  BASCO  quality 
—  keen  sensitiveness  —  deep,  natural-voice  pitch  — 
lightweight- — head  comfort — these  features  should 
direct  your  choice  in  selecting  BASCO  Phones  for 
allround  satisfaction. 

See  BASCO  Phones  and  other  units  of  the  com- 
plete BASCO  Radio  Line.  If  your  dealer  can't  sup- 
ply you,  write  us  direct. 


$65 


2000 
Ohms 


Ohms 


Jobbers  and  Dealers! 

Wtite  for  attractive  sell- 
ing proposition  and 
name  of  our  nearest  local 
factory  representative. 


miiiiiiiiuiin:^~vx;iiiiiii;iliiliii 


BrififSfs 

epgJI^Stratton  <s 

l  ROoUL I"""  Milwaukee. Wisconsin 


Showing 
One 
Phone 


Warren  Radio  Loop, 
cut  away  to  show 
construction 


~h   d-''^f*^'     i'"^*"^*'  Simpler, 
Sharper  Tuning 
with  a 

Warren  Radio  Loop 

AERIAL  and  tuning  device  all  in  one.  Tunes  not  only  to 
t.  wave  length  but  to  wave  direction.  An  aid  to  selection. 
Eliminates  atmospherics.  All  enclosed, — damp  and  dust 
proof,  fool-proof  and  surprisingly  compact,  neat  and  dur- 
able. Write  to-day  for  Bulletin  X-I02  containing  hookups. 

A  Type  for  Every  s^t  At  the  Best  Dealers 

Type-A-737  (300-700  meters)  6  inches  square — non- 
directional  -  $10. 

Type-A-7236  (175-1000  meters)  6  inches  square — non- 
directional  $1 2. 

Tvpe-B-2537  (300-710  meters)  18  inches  square — direc- 
tional „  $20. 

Type-BL-2520   (200-18,000  meters)  with  honeycomb  coil. 

18  inches  square — directional  $25. 

V-DE-CO  RADIO  MFG.  CO. 

Dept.  B  Asbury  Park,  N.  J. 


6  Volt  120  A.H.  RADIO 

BATTERY  IN  LEAK  $^P00 
PROOF  RUBBER  CASE    ^9  ~ 


The  Radio  Battery  You  Have  Been  Waiting  For 

A  high  grade,  long-life,  11  plate  radio  battery 
in  absolutely  leakproof  rubber 
composition  case  with  victrola 
style  cover.  Protects  your  rugs 
and  floors  from  destructive 
acid.  Makes  your  "A"  battery 
as  handsome  as  your  receiv- 
ing set. 

Positive  18  Months  Guarantee 
Guaranteed  for  full  18  months 
of  service.  Non-warping  cedar 
separators,  highest  quality 
plates  of  generous  thickness.  6 
Volt — 120  Ampere  hour  type. 
Sealed  terminals  save  electro- 
lyte and  protect  connections. 
Positively  will  not  short  cir- 
cuit. Fitted  with  convenient 
handle-  and  anti-drip  tray. 
Price,  complete,  fully  charged, 
$25.00.  Neat  switch  in  cover  supplied  for  $1.50  extra. 

NOTE  THESE  LOW  "A"   BATTERY  PRICES 


as  its  name" 


S14.N0 
17.90 
19.70 
21.70 


Noble  Radio  "A"  Batteries  in 
Everlastic  Rubber  Cases 

Type        Rating  Plates  Price 
Junior  ..  ..  80  Amp.  7 
Senior  ....100  Amp.  9 
Standard  120  Amp.  11 
Superior  ..140  Amp.  13 
Covers  for  above 
b&tt.    $1  extra. 
You  may  be  able 
to  buy  batteries 
as  good  as  ours, 
but    none  that 
are  better. 


Noble  "A"  Batteries  In  Maple 
Cases,  Black  or  Mahog.  Finish 

Type         Rating  Plates  Price 
Junior  .. ..  80  Amp.     7  $12.75 
Senior  ..  ..100  Amp.     9  15.90 
Standard  120  Amp.    11  17.75 
Superior  ..140  Amp.    13  19.45 
Order  today, 
sending  check  or 
P.  O.  money  or- 
der, or  we  ship 
express  C.  O.  D. 
same  day  order 
Address  Dept.  B  is  received. 


mm 


N  OB L  E   BATT  ER I ES 

1454  MO  NAD  NOCK  BLOCK  -  CHICAGO 


RADIO  BROADCAST  ADVERTISER 


THE  RADIO  SET  OF  THE  FUTURE 


IT  cannot  be  foretold  what  combination  of  units  will  be  used,  or  the  cir- 
cuits that  may  be  employed  in  the  Receiver  of  tomorrow.  It  is  obvious, 
however,  that  today's  conventional  set  will  soon  be  considered  crude  ana 
antiquated. 

Little  prescience  is  requjr^t^TP^fee:  thatHhejpanel  of  insulating  mate- 
rial, with  its  shielded^tickground, is  doomed  to^bbsolescence.  The  use  of 
a  great  mass  of ^^^isiyej.ihsula^^rnnaterial  Jo  provide  for  "live  shafts" 
was  merely  a/fempbrary  expedient.  Progressive  ^practicV  has  eliminated 
the  electrical  difficulties  connected  with!  live  shafts  and  also  obviated  the 


necessity  for  massive  insulation. 


Carrying  primary  leads  to  the  panel,  and  the  drilling  of^numerous  holes 
for  a  switch,  will  cease  because  ofj j  the  waste  such  labor  entailsf»\ \To  make 
the  tap-switch  an  integral  part  of  the  instrument  is  the  expedient  th|ng  to  do. 


Knojps  add  nothing  to  the  appearance  of  a  panel,  and  will  in  time  become 
The  concaye^dial  and  bar  control,:  giving  ease  of 
adjustment  without  cramping  the  hand,-is  far  more  sensible/and  attractive. 


a  relic  of  bygone  days. 


f\A\      1     1     '  :  I1 

EISEMANN  PARTS  AND  PANELS 


^\  Permi^vchanging  circuits  and  re-location  of  parts  on  panel 
^\all  units  ibeing  interchangeable.!  y  ' 

accessary  the  use  of  shielding-^-the  metal  p£mel 
itself  ^accomplishing  this_purpose, 

oldering  of 


Eliminat 


primary  leads^ 

Give  the  many  advantIges~of~concave  dials — a  natural 
position  of  the  hand  in  tuning,  added  attractiveness  in  appear- 
ance and  ease  in  packing  for  transportation. 


Write  for  descriptive  literature. 


EISEMANN  MAGNETO  CORPORATION 

William  N.  Shaw,  President 
BROOKLYN,  N.  Y. 

OETROIT  CHICAGO 


RADIO  BROADCAST  ADVERTISER 


Fill 

1 


UDIOL 


C  H  I  C  A  G  O 


GET  acquainted  with  Radio  by 
buying  an  Audiola  Crystal  Re- 
ceiving Set. 

The  23-plate  variable  condenser 
insures  sharp  and  accurate  tuning. 
It  is  a  complete  unit,  in  a  rich  ma- 
hogany finished  case,  with  nickel 
plated  fittings. 

Needs  no  batteries,  no  tubes,  no 
fussing.  Just  connect  it  with  aer- 
ial, ground  and  head  phones,  and 
"listen  in."  1 

Price  $10  I 

Complete 
(without  headphones) 

At  your  dealer  or  write  direct 
for  illustrated  booklet. 

Audiola  Radio  Co. 

430  S.Green  St., Chicago 

We  can  use  a  feu-  high-class 
representatives  for  ex- 
clusive territory. 


1200  MILES 

With  a  Crystal  Set  Using 


THE  WORLD'S  GREATEST 
RADIO  CRYSTAL 


A  Needles,  California,  radio  fan  writes: 

"Using  M.  P.  M.  Crystal,  I  picked  up  Los 
Angeles,  San  Francisco,  Salt  Lake,  Denver 
and  St.  Louis.  It  is  far  superior  to  any 
crystal  I  have  ever  used." 

Before  Discarding  Your  Crystal  Set  for  an 
Expensive  Tube  Outfit,  Give  M.  P.  M.  Crystal  a  Trial 

<I  Beware  of  Imitations.  The  genuine 
Million  Point  Mineral  is  sold  only  in  separ- 
ate crystals  packed  by  our  company  in 
boxes  bearing  the  trade-mark  "M.  P.  M." 

Send  25c  and  name  of  your  Radio  Dealer  for  a  sample 
M.  P.  M.  Crystal — concert-tested  and  guaranteed. 
35c  for  mounted  Crystal. 

M.  P.  M.  SALES  CO. 

Dept.  B 

247  So.  Central  Ave.       Los  Angeles,  Cal. 


I"*    "TRADE    *^    Ci  f    MAW^"T""  • 

PATENT   APPLIED   FOR  y~^,§_ 

Link 
ihKADIO 

Stops  Interference/ 

The  "WAVE  TRAP"  will  eliminate  inter- 
fering broadcasting  stations  and  enable  you  to 
listen  to  your  favorite  station. 

It  will  work  on  any  set,  greatly  increase  its 
selectivity  and  clearness,  and  eliminate  code  and 
spark  stations. 

It  is  mounted  on  a  Formica  panel  in  a  hand- 
some mahogany  finished  cabinet  6x5x6:  It  is  a 
high  grade  instrument  throughout  and  a  valuable 
addition  to  the  operation  and  appearance  of  any 
set.  It  comes  to  you  complete  and  there  are  no 
extras  to  buy.  It  is  installed  in  a  minute  by 
changing  only  one  outside  connection. 

Use  the  "WAVE  TRAP"  for  real  results. 


19  E .  SOUTH  WATER,  ST. 

CHICAGO 

Circular  on  Request 


Waiting  in  the  Wilderness 

by  ENOS  A.  MILLS 

Adventures  close  to  nature  in  the  Rocky  Mountains, 
with  pleasant  by-paths  into  the  realms  of  animal  lore. 
A  book  no  one  could  help  enjoying.    Illustrated  from 
16  beautiful  photographs.    Net,  $2.50. 
DOUBLEDAY,  PAGE  &  CO.         GARDEN  CITY,  N.  Y. 


NARKO 


„  RADIO 

ALWAYS  DEPENDABLE 


MARKO  STORAGE  BATTERY  CO. 


1408  Atlantic  Ave. 


Brooklyn,  N.  Y. 


Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


Reproducing 
Revolutionized 

Based  on  our  experience  of  over  a  quarter  of  a  century,  as 
manufacturers  of  musical  instruments — and  as  highly  specialized 
accoustical  engineers,  we  have  produced  the  PATHE  LOUD 
SPEAKER  which  will  mark  a  new  era  in  loud  speakers. 

It  is  something  decidedly  different.  It  utilizes  an  entirely 
new  principle.  And  as  a  result  it  converts  tone  with  an  exactness 
never  before  accomplished  by  a  "loud  speaker." 

No  horn  of  any  type  is  used.  No  small  metallic  diaphragm 
is  hidden  away  at  the  end  of  a  horn  or  in  the  depths  of  a  cabinet. 
What  you  suppose  on  first  inspection  to  be  a  stubby  sort  of  a  horn, 
is  a  parchment  diaphragm  of  abnormal  size. 

WITHOUT  DISTORTION  the  sounds  are  given  directly  from 
this  diaphragm,  propagating  the  waves  in  free  air  rather  than  by 
reflection  from  a  horn. 

The  Pathe  Loud  Speaker  possesses  an  unrivaled  combination 
of  distinct  advantages.    Briefly: — 

It  distributes  the  sound  in  all  directions — and  does  not  confine 
or  "shoot"  it  toward  one  point  as  a  horn  does. 

It  d.oes  not  require  an  extra  batten .    Simply  attach  it  in 
place  of  the  ear  phones. 

On  the  home  sets  of  two  steps  of  amplification  it  will  flood 
the  room  with  clear  tone.  On  larger  sets,  it  will  produce  any 
volume  of  sound  required— WITHOUT  DISTORTION. 

It  is  compact,  size  145"  high  x  7"  wide,  and  it  will  grace 
any  living  room. 

The  cost  is  much  lower  than  you  expect — ■ 
$24.  for  nickel  finish 
$22.  for  Japan  Green  finish 

If  vour  dealer  has  not  received  his  Pathe  Loud  Speakers,  we 
will  make  you  shipment  direct  from  the  factory.  Simply  en- 
close money  order  or  check  and  say,  send  me  The  Pathe  Loud 
Speaker. 


Pathe  Phonograph  &  Radio  Corporation 
Dept.  4345  20  Grand  Ave.  Brooklyn,  N.  Y. 


Send  the  Coupon 

I   Pathe  Phonograph  &  Radio  Corp., 
j  Dept.  4345,  20  Grand  Ave.,  Brooklyn,  N.  Y. 

:  Please  send  me  the  Pathe  Loud  Speaker. 

■  I  am  enclosing  $   It  is  distinctly  understood  that  I  may 

I  return  the  Loud  Speaker  if  it  is  not  entirely  satisfactory — and 
(  my  money  will  be  cheerfully  refunded. 

I         Name,  , 

Address  

Town,  


Mdhe  the  World  OiXtr 


•fa  Tested  and  approved  by  Radio  Broadcast  -^r 


RADIO  BROADCAST  ADVERTISER 


* 

The  Meaning  of  the  Star 

THE  chief  danger  in  the  development  of  radio 
is  the  prevalence  of  inferior  and  unsatisfactory 
apparatus.  The  demand  for  radio  equipment 
that,  for  a  time,  could  not  be  fully  met  by  the 
manufacturers  of  standard  goods,  naturally  flooded 
the  market  with  radio  sets  and  parts  of  poor  de- 
sign and  slip-shod  workmanship.  Many  new  en- 
thusiasts turned  away  with  disgust  because  of 
failure  resulting  from  this  so-called  "bootleg" 
apparatus.  Much  of  it  is  still  offered  for  sale  with 
ridiculous  claims  at  cut  prices. 

To  Safeguard  Its  Readers,  RADIOBROADCAST 
will  permit  manufactures  to  include  a  black  star  in 
the  advertisements  of  sets,  materials,  parts,  and 
accessories  that  have  been  tested  by  its  experts 
and  found  to  be  worthy  of  indorsement.  This 
approval  will  cover  both  design  and  workmanship. 

The  absence  of  the  RADIO  BROADCAST  star 
will  mean  that  the  article  advertised  has  not  been 
offered  for  test  and  that  this  magazine's  experts 
have  not  personally  used  it.  The  acceptance  of  an 
advertisement  in  itself  indicates  a  belief  in  the  in- 
tegrity of  the  manufacturer.  But,  the  appearance 
of  the  star  means,  in  addition: 

Tested  and  Approved  by  RADIO  BROADCAST 


RADIO  BROADCAST  ADVERTISER 


GO 


Control 


Co  mp" 1500 
Adju*uneM 
Control  RmI« 

Witb  RheolUU 
.nd  Otb«T 
Filament  . 
Control* 
Clemrly 

IndiotM  i 

FUk«Ut 

Superiority.  »•  I* 

V/ilh  Infinite 
Adjustments. 


pmni'iiu. —  -7- 

1  just  t*'f«"dJ»  f(  arpar»»s  forw 

set  builders,  amateurs  a  to  the  advent 
S.V  ™Th«  have  r.ah»ed 

of  just  such  a  ocv'ct-  so^alled 

filament  heat.  »"  ,  current,  fine  cur- 
ies as  the  square  of  tnc  extremely  neees- 
i°t  regulation  become  erfreme 
Lrv  W  accomplish.  l»»  «  .  s  thc  elec- 
SWdStrons..  ^"f'^Trmits  the  «nr 
Tronic  flow  in  the  WW  »The  f,„e  ad.ust- 
SS  «  Sr'sS "start?  s'-»'»  before 


Sere  is,  '8tl0  deSrKS~ 

at  maximum  heat.  » 


■    ,  te  life.   Further-  T 
-^;^%c^ss,n,n- 

control  ideal  ;     including  ample    ( ; 

The  perfection  of  des»3         (his        m.  _ 

The  lower  .curve  on  me  s  i  pleat's 
elonuent  testimony  as i»  ^  Thfse. 
;d.ptaM.'>y  <°,ya"*  faction  of  an  ampere 
tuhes  using  on Y  »  J   „iat  is  s0  finely  ad-- 

abruptly  h>?£'mf£»£k  : 
practically  zero.        .        j  a  b„How  cylin- 
tta^SV'^.n^ie.no, 


Seases  ol !  UTOg  J,.^  « 
d,9r«,  »"h  c "  '„,„  ,l,c  filament  to  UW 

i  nNGER  TUBE  LIFE;  NO  NOISES 
LONGER  1U  erils  the 

™V*^„oTtn«  n lST.hU  so  many 


The  1FlTk0*r,p^,l5 


,y  other  control 
ilhout  redr.llu.l- 


fi"C,-blc'V'Tn^ere  are  °o  disks  to  break  or 
S*'JUr<WAHCE  remains  CONSTANT 

lions  once  set.  b"  ^.^  excepting  n 
Smg'out^auonsandno^^ 
,hc  laboratory    »hcre  s  ^  maJc  bj 

show,  on  -he  ato  e  grap  olhcr  ,s 

Sr^rtAtforthc-'FtlkosUit  are 
diately  apparent. 


Replace  Old  Style  Current  Controls  with  the 
NEW  FlL-KO-STAT  a  real  Filament  Control 
ON  SALE  AT  RADIO  DEALERS  EVERYWHERE 


cManuCictured  <By 


("/CTlNSTRUMENTOO 


If  your  dealer  has  none  in  stock  yet  send  $2.00  and  his  name  direct  to 

SOLE  liNTTERNATIONAL  DISTRIBUTORS 

RADIO  STORES  CORPORATION 

Dept.  R.  B.  218-222  West  34th  Street.  New  York 


SNVThe 
tluimfnt 

ROIltTOl 


CURRENT  INCREASE  PERFECT  AND  GRADUAL 

IKE  1HE  USING  SUM 

$2Q0 

—and  here's  why 
you  need  it!! 

Designed  For  Vacuum  Tube 

adjustment  and  not  just  an  old  method  adapted  to  It. 
NOT  a  Rheostat 

—but  a  REAL  Filament  Control. 
Infinitesimal  Control-of  filament  heat 

and  therefore  of  electronic  /lou.. 
Very  Finest  Tuning  for  DX 

is  realized  with  Fil-Ko-Stat. 
Controls  Fractional  Currents 

—making  it  ideal  for  use  with  any  dry  cell  tube. 
Fine  Adjustment  Starts 

—where  tube  commences  to  function  increasing  the  AREA 
OF  FINE  ADJUSTMENT  CONTROL. 

Definite  Off— 

an  important  feature   indicating   complete    'A'  Battery 

disconnection. 
Resistance  Practically  Zero 

at  "full  on"  there  is  practically  no  resistance  In  circuit. 
No  Disks  To  Break  or  Chip 

Resistance  Element  is  so  finely  divided  further  division 

Absolutely  Silent 

The  Fil-Ko-Stat  is  non-mictophonic   and  operates  fteo 

of  all  noises. 
Fahnestock  Clips 

and  solder  contacts  on  connection  posts. 
Adjustable  Mounting 

—no  re-drilling  of  panel  neccessary. 

GUARANTEED 

The  FIL-KO-STAT  is  to  all  purposes  "tool 
proof".  £ach  msfrumenf  is  packed  with 
the  maker's  guarantee  that  tfuiiH  be  re- 
placed if  broken  within  one  year. 


RADIO  BROADCAST  ADVERTISER 


Can  be  used 
with  6-volt  or 
WD  11  detector 
tubes,  two 
amplifying  bulbs  or  one 
S-Watt  power  tube. 
The  difference  between  a 
jumbled  mass  of  signals  com- 
ing from  everywhere  and 
the  "sharply-tuned"  concerts 
received  clearly  and  distinctly 
from  far-away  stations  depends 
argely  upon  the  careful  adjust- 
ment of  your  detector  filament 
current. 

Heretofore,  sharp  tuning  has 
only  been  partially  obtained 
thru  skillful  "hair-breadth" 
manipulations  of  the  filament 
rheostat.    But  with 


A  Super 
Radio  Rheostat 


these  much-sought-for  results 
can  be  secured  by  anyone. 
Just  "twirl  the  knob"— a  full 
turn  produces  a  finer  adjust- 
ment than  a  "hair's-breadth" 
turn  on  any  other. 
Economical  —  neat  —  small  — 
compact.  No  carbon  to  break 
or  change  resistance.  Unqual- 
ifiedly guaranteed.  Popularly 
priced — $1.36. 

//  the  Best  is  none  too  good  for 
the  set  you  are  building  or  have 
bought,  see  the  Autostat  at  any 
good  radio  or  electrical  dealer 
Today.  Or  write  direct  for  Free 
Bulletin  which  shows  why  the 
Autostat  is  radio' s  Bestrheostat. 

DEALERS  —  JOBBERS 
Write  or  wire  for  Radio's  most 
attractive  merchandising  prop- 
osition. 

THE  AUTOMATIC 
ELECTRICAL  DEVICES  CO. 
128  West  Third  St. 
Cincinnati,  Ohio 


Convert  Your  Crystal  Set 
Into  Tube  Set  at  Small  Cost 


You  can  now  enjoy  wider  range, 
greater  volume  of  sound  and 
purer  tone  and  do  away  with  feel- 
ing around  for  a  sensitive  spot,  if 
you  make  a  Tube  Set  out  of  your 
Crystal  Set  by  adding  the  Peanut 
Tube  W.  T.  501  and  a  few  other 
inexpensive  accessories.  Full  di- 
rections packed  with  every  W.  T. 
501. 

Welsh 

PEANUT 

Detector  Tube 

W.  T.  501 

can  be  used  on  three  cLy  cells 
or  one  regular  6-V  "A"  battery. 
Consumes  less  than  half  as 
much  current  as  ordinary  tubes, 
consequently  does  not  use  up 
batteries  as  fast. 

Nickel-plated     socket,  moulded 
base,  double-spring  contacts,  40c 
extra.     Adaptor   for  standard 
V.  T.  Socket,  75c  extra. 

If  not  at  your  dealer's,  send 
us  his  name  and  address  with 
money  order  and  we'll  see  that 
you  are  supplied.  Include  10c 
extra  for  registration. 


Radio  Research  Guild 

40  Clinton  St       Newark,  N.  J. 


Immediate 
Delivery 


HOW  ABOUT— 

Your  Summer  Radio 

Reading  Plans 
?  ?  ? 

•    •  • 

Here's  a  chance  to  order  RADIO  BROAD- 
CAST for  5  months  at  reduced  price.  Just 
sign  and  send  in  coupon  below 

Read  these  articles  in 

RADIO  BROADCAST 

for  June — 

The  New  Westinghouse  System  of  Broadcasting 
Blind,  but  He  Built  His  Own  Radio  Set 
All  About  Our  Boy  Scouts  Prize  Contest 
How  to  Built  a  Single  Tube  Loud  Speaker 
Operating  a  Radio  on  a  Yacht  in  Mexican  Waters 

FIVE  BIG  ISSUES  FOR  ONE  DOLLAR! 

Doubleday,  Page  &  Company  MAIL  NOW 

Dept.  523-R,  Garden  City,  N.  Y. 

Enclosed  please  find  $1.00  for  which  special  price  kindly 
send  me  the  next  5  issues  of  Radio  Broadcast,  commencing 
with  June. 

Name  

Address  

City.  State  


RADIO  BROADCAST  ADVERTISER 


INDISPENSABLE  to  every  radio 
owner.  Contains  up-to-date  list  of 
over  20,000  Amateur,  Commercial, 
Army,  Navy,  Transoceanic  High  Power- 
ed, and  Broadcasting  Stations  in  the 
United  States  and  Canada;  Internation- 
al Morse  Code  and  Convention  Signals; 
the  construction  and  operation  of  the 
Reinartz  Tuner,  Detector,  and  one-stage 
Amplifier;  also  an  abundance  of  other 
useful  information. 

Included  with  the  book  is  a  splendid  two- 
color  map  of  the  United  States  and  Canada, 
2x3  ft.,  showing  radio  district  boundaries, 
standard  time  lines,  geographical  location  of 
broadcasting  stations,  etc. 

Buy  the  book  with  the  blue  cover. 

Greatest  dollar  value  on  the  radio  market. 
At  your  dealers  or  direct  by  mail.  Use 
check  or  money  order.    Do  not  send  stamps. 

Dealers:  W rite  for  proposition 
RADIO  DIRECTORY  AND  PUBLISHING  CO. 
45-W  Vesey  Street  New  York  City 


CHARGE  YOUR 
RADIO  BATTERY 
at  HOME/S^aNICKEL 


Enjoyable  concerts  and  maxi- 
mum receiving  range  are 
obtained  only  when  your  battery 
is  fully  charged. 


THE 

HDMCHARGER 

charges  your  "A"  or  "B" 
battery  OVER  NIGHT  for  a 
nickel  without  removing  it  from 
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silently  —  charging  rate 
governed  automatically.  No 
muss — no  trouble — no  dirt — 
requires  no  watching. 

The  HOMCHARGER  is  the 
ONLY  battery  charger  combin- 
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charging  rate — UNDERWRIT- 
ERS' APPROVAL— beautifully 
finished  in  mahogany  and  old 
gold — U  NQTJALIFIEDLY 
GUARANTEED.  Over  100,000 
now  in  use. 

The  minute  you  buy  a  radio 
set  you  need  a  Homcharger — get 
it  then.  All  good  radio  and 
electrical  dealers  sell  it  com- 
plete with  ammeter,  etc.,  for 
$18.50.     $25.00  in  Canada. 

Write  for  FREE  circular  show- 
ing why  the  HOMCHARGER 
is  the  BEST  battery  charger  at 
any  price. 

MOTORISTS  —  THE  HOM- 
CHARGER will  also  charge 
your  AUTO  Battery. 

THE  AUTOMATIC 
ELECTRICAL  DEVICES  CO. 
128  West  Third  St. 
Cincinnati,  Ohio 


•jr  Tested  and  approved  by  Radio  Broadcast  -fa 


RADIO  BROADCAST  ADVERTISER 


HERE'S  WHAT  YOU  GET  FOR  $10 

z.  "The  How  and  Why  of  Radio  Bioadcasting-"— the  book  and  work- 
ing charts  that  tell  you  just  what  you  need  to  know  about  radio, 
free  with  each  order  until  further  notice. 

2.  Parts  for  the  receiver  cabinet. 

3.  Specially  finished  front  panel. 

4.  All  the  parts,  including  stators,  rotors,  axles,  friction  washers, 
rotor  balls,  and  wire  for  two  variometers. 

5.  All  the  parts  for  one  vario-coupler. 

6.  Metal  indicators. 

7.  Control  knobs  for  tuning  devices. 

8.  Vacuum  tube  socket.  A 

9.  Rheostat. 

10.  Wire  for  winding  vario-coupler  and  variometers.  V-^ 
ix.  Grid  leak  and  condenser  unit. 

12.  Inductance  switches  for  vario-coupler. 

13.  Contact  points  for  vario-coupler. 

14.  Spring  connectors  for  making  an  easy  job  of  the  wiring. 

15.  Eight  binding  posts. 

16.  Hard  drawn  copper  wire  for  making  sul  istantial,  bus-type  con- 
nections. 

17.  Metal  foil  for  making  the  shield  which  cuts  out  "howling,"  due 
to  "body  capacity,"  effect. 

18.  Complete  soldering  outfit,  including1  soldering  iron,  solder,  resin 
and  scraper — just  the  thing  for  radio  work; 

Everything  is  here  to  enable  you  to  build  a  receiver,  without  any 
special  tools,  without  requiring'  any  knowledge  of  radio,  without  any 
complicated  parts — but  with  all  the  advantages  of  an  expensive  re- 
ceiver at  about  one-sixth  its  usual  cost.  And  you  have  all  the  fun  of 
making  it. 


1300  Miles  and  More 
On  a  KD-10  Receiver 

Using  a  2  wire  antenna  less  than  40  feet 
above  the  ground  and  a  receiver  he  built' for 
$10,  Theodore  Bedell,  Jr.,  of  Freeport,  L.  I., 
hears  Havana,  Cuba;  Davenport,  Iowa;  At- 
lanta, Ga.,  and  many  other  distant  broad- 
casting stations. 

Just  the  Outfit  for  that  Boy! 

Send  money  order  to-day  for  a  KD-io — the  biggest  $10 
worth  you  ever  bought.  Add  postage  for  points  outside 
the  U.  S.  A. 

We  can  also  supply  standard  radio  equipment  of  all 
makes  at  list  prices. 

KAY  DEE  RADIO  SUPPLY  CO. 
487  Fulton  Street,  Brooklyn,  N.  Y. 


ALL  THESE  PARTS  FOR  $10 


BROOKS  VARIABLE  CONDENSER 

Two  Ribbons  furnished  (Max.  .0005  Min.  .00001) 
Easily  interchangeable  (Max.  .001  Min.  .0000  V 


Adaptable  to  all 
receiving  circuits. 


Shortening  of  plates 
eliminated. 


Nicety  of  adjust- 
ment. 


Straight  line  capac- 
ity curve. 

Low  internal 
resistance.  > 

Loud  Signals 


Jobbers  Wanted 


Write  for  prices 
and  discounts 


Retail  price  $4.75 
each,  complete  wit! 
dial. 


Manufaatured  by 

METRIC  METAL  WORKS 

of 

AMERICAN  METER  COMPANY,  INC. 

ERIE,  PA. 


■^C  Tested  and  approved  by  Radio  Broadcast  •fa 


RADIO  BROADCAST  ADVERTISER 


HA  VA  NA  ! 


AT  LAST! 


You  Can  Now  Make 
Your  Own  Receiver  at  a 
TOTAL  COST  of  ONLY  $10.00 


THE  HOW  AND  WHY 
OF  RADIO  BROAD- 
CASTING, by  Arthur  H. 
Lynch,  is  the  book  radio 
amateurs  all  over  the  coun- 
try have  been  looking  for. 
It  is  complete  in  every  de- 
tail and  makes  it  possible 
for  you  to  build  a  modern 
set,  capable  of  receiving 
over  great  distances,  with- 
out interference. 

To  buy  a  similar  receiver 
would  cost  you  at  least  five 
times  as  much. 

Four  working  patterns  accom- 
pany each  book  and  they  are  used 
for  making  the  panel,  cabinet  and 
electrical  units. 


3  9  Bedell  Street,  Freeport.  N.  Y. 
September  9,  1! 
Douhleday,  Page  &  Co., 
Garden  City,  N.  Y. 
Gentlemen: 

It  may  interest  you  to  know  the 
results  I  am  getting  from  the  vacuum 
tube  receiver  I  made  from  the  plans 
which  came  with  your  pamphlet  "The 
How  and  Why  of  Radio  Broadcasting," 
by  Arthur  H.  Lynch. 

The  stations  of  WJZ,  WOR, 
WEAF  and  WBAY  come  in  regularly 
and  very  clearly.  Also,  I  receive 
from  WGY,  KDKA  and  WOO  and  have 
no  trouble  to  tune  them  in  over  the 
above  named  stations. 
We  hear  Havana.  Cuba,  very  well. 

Being  an  amateur  and  with  no  radio 
experience  whatsoever  two  months  ago, 

1  attribute  the  results  I  am  getting  to 
your  publication,  which  is  certainly 
complete  and  easy  for  anyone  to  under- 
stand. 

In  connection  with  the  receiver,  I 
use  an  aerial  100  feet  long,  2  wires — - 

2  feet/  apart,  40  feet  high— and  a  35- 
foot  lead  in.  Also  a  single  vacuum 
tube,  a  six  volt  storage  battery  and  a 
22  V2  volt  "B"  battery. 

I  also  wish  to  state  that  the  tone  of 
reception  is  excellent,  and  in  compar- 
ison with  outfits  owned  by  friends, 
costing  five  or  six  times  as  much  as 
mine,  my  results  compare  favorably 
and  in  many  instances  surpass. 

Yours  very  truly, 
THEODORE  BEDELL,  Jr. 


One  of  the  receivers  built  by 
the  author  is  in  use  in  the  office  of  "Radio  Broadcast' 
and  is  giving  entire  satisfaction. 

The  set  is  designed  for  use  with  a  single  vacuum  j 
tube,  but  amplifiers  may  be  used  if  desired. 

The  stations  mentioned  in  this  letter  include  two  I 
in  Newark,  N.  J.,  two  in  New  York;  one  each  in  I 
Schenectady,   Pittsburgh,   Philadelphia  and    Atlanta,  I 
Ga.,  one  in  Havana,  Cuba,  ranging  from  30  to  1350  I  Name... 
miles.    Still  greater  distances  are  possible.  I 

I  Address. 


This  book  tells  you  all 
you  have  to  know: 

How  to  put  up  your  antenna  in 
accordance  with  the  new  regula- 
tions of  the  National  Board  of 
Fire  Underwriters — 

How  to  wind  coils,  drill  the 
panel,  make  the  cabinet,  solder 
connections-shield  your  receiver — 

How  to  operate  your  set '  in- 
telligently— 

How  to  overcome  interference 
and  other  troubles — 

How  to  prolong  the  life  of  your 
vacuum  tube — ■ 

How  to  use  "vernier"  adjust- 
ments— 

In  short — everything  you  want 
to  know  about  in  radio  language 
you  can  understand. 

There  are  more  than  two  dozen 
photos  and  diagrams  in  addition 
to  the  four  working  patterns. 


DOUBLEDAY,  PAGE  &  COMPANY 

Dept.  RB-2,  Garden  City,  New  York 

Gentlemen:  Enclosed  please  find  one  dollar  for  THE  KOW 
AND  WHY  OF  RADIO  BROADCASTING  by  Arthur  H. 
Lynch.  If  not  satisfied  I  can  return  this  book  within  3  days 
and  have  my  deposit  refunded. 


RADIO  BROADCAST  ADVERTISER 


—  ^they  last  longer 


9) 


Insist  on  Ereready — 
Accept  no  Substitute 


* 


For  Storage  Battery 

Tubes  use  EVEREADY 
Storage  "A"  Bat- 
teries 

For  Dry  Cell  Tubes 

use  EVEREADY 
Dry  Cell  Radio 
"A"  Batteries 

For   All  Vacuum 

Tubes  use  EVEREADY 
"B"  Batteries 


NATIONAL  CARBON  COMPANY,  Inc. 

Long  Island  City,  N.  Y. 
Atlanta     Chicago     Cleveland     Kansas  City    San  Francisco 

EVEREADY 

Radio  Batteries 

—they  last  longer 


•fc  Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


c^IKE  THE  POWERFUL  TELESCOPE 

that  makes  us  neighbors  to  the 
stars,  Mu-Rad  Receivers  annihi- 
late distance  with  delightful  ease. 
Honolulu  is  as  nearto  St.Louisby 
Mv-Rad  reception  as  New  York. 

So  marvelously  sensitive  that  it 
requires  only  a  2-foot  loop  aerial. 
Distinct  reproduction  with  hair 
breadth  selectivity,  and  yet  easy 
for  even  a  novice  to  operate.  Con- 
servatively guaranteed  for  iooo 
miles. 

W rite  for  literature 


Star 
theRadio 
World 


Mu-R/ID  L/IBOR/rrORIES.lNC. 
-^>-  803  Fifth  /Ive./IsburyP/irk.  New  Jersey 


•fa  Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


Lon 

distant 


Licensed  under  Armstrong  U.  S.  Patent  No.  1,111.149,  manufactured 
by  Oard  Radio  Laboratories,  Stockton,  California,  Atlantic- Pacific  Radio 
Supplies  Co.,  Sole  Agents. 

You  are  losing  a  vast  amount  of  radio  enjoyment 
every  day  you  are  without  Type  AR-io  Long-distance 
Regenerative  Receiver  and  Two-stage  Amplifier.  It  brings 
in  distant  programs,  too.  The  reception  of  music  and 
speech  a  thousand  miles  and  beyond  is  considered  not  at 
all  extraordinary  by  owners  of  this  marvelous  set. 

It  is  simple,  beautiful,  sturdy,  and  efficient — a  com- 
plete set  of  the  most  practical  type  with  the  latest  ac- 
cepted improvements. 

And  so  compact — with  WD  1 1  ("Peanut")  tubes  there 
is  room  for  both  A  and  B  batteries  inside  the  cabinet, 
and  only  two  external  outlets  are  required,  one  for 
ground,  and  one  for  antenna.  (Standard  tubes  can  be 
used  if  preferred.) 

The  lew  price  only  possible  because 
of  quantity  production  and  organized     W  A 
facilities  of  manufacturer,  who  is  one  of    m     f\  fi-M 
the  oldest  in  radio.  |  ^*  ■*»  A 

Don't  delay.    For  several  months    »  QtUMIctJ 
the  demand  for  AR-ios  will  probably    \      LjT2<>  ' 
exceed  the  number  that  can  be  pro- 
duced.   Mail  the  coupon  NOW! 

ATLANTIC-PACIFIC 

RADIO  SUPPLIES  CO. 

650  Mission  St.,   San  Francisco,  California 

MANUFACTURERS'  REPRESENTATIVES 

Cutler-Hammer  Mfg.  Co  Rheostats  and  Potentiometers 

Alden-Napier  Co  Sockets  and  Dials 

Carter  Radio  Co  Telephone  Plugs  and  Jacks 

Dayton  Fan  &  Motor  Co  Variometers  and  Variocouplers 

A-P  Quality  Line  Transformers,  Condensers,  etc. 

Oard  Radio  Laboratories. . .  ^  .Oard  Phantom  Receptor 

JOBBERS  and  DEALERS  invited  to  stock  these  lines 


r>Gcetr>er>  with 

two  ~  stage 

amplifier*- 


Construction  and  Perform- 
ance FULLY  GUARANTEED 


MAIL  THIS  COUPON 

Atlantic-Pacific  Radio  Supplies  Co. 

650  Mission  St.,  San  Francisco,  Cal. 

Gentlemen: — Without  cost  orobligation,  please 
mail  me  folder  giving  fulIMnformation  on  your 
Type  AR-io  Regenerative  Receiver  and  two- 
stage  Amplifier. 


ADDRESS- 
CITY  


My  favorite  radio  dealer  is — 


ADDRESS  - 
CITY  


RADIO  BROADCAST  ADVERTISER 


M ahogany  finished  case,  of  rugged  build. 
A  three  tube  Radiola — detector  and  tiro 
steps  of  amplification. 


aA  New  Improvement 

Lowers  the  Cost ! 


Dry  cells  replace  storage  batteries.  A  new 
vacuum  tube  has  made  it  possible.  Radiola 
V  and  Radiola  RC  have  been  topping  them 
all  in  popularity  for  dependability  and  long 
range  —receiving  over  thrilling  distances  -  up 
to  1,500  miles  and  more.  Now  both  are  con- 
verted to  dry  battery  operation.  This  means 
greatly  lowered  cost — does  away  with  bulky 
storage  batteries — gives  the  far-away  farmer 
the  same  good  service  it  gives  the  city  man. 

No  more  need  for  expensive  storage  battery 
and  charger.  A  big  saving!  And  a  saving 
made  greater  by  the  new  offer — a  combin- 
ation offer  of  receiver  and  accessories — 
complete  at  a  price  remarkably  low. 

'There's  a  RADIOLA  for  every  purse" 
at  the  nearest  Radio  or  Electrical  Store 

Radiola 


77?  is  symbol  of 
quality  is  your 
protection 


Radiolala  V  or 

Radiola  RC 

Complete  $142.50 

The  New  Way :  Complete  for  dry  battery 
operation,  including  three  WD-12  Radiotron 
vacuum  tubes;  head  telephones;  "A"  battery 
consisting  of  three  dry  cells;  "B"  battery  con- 
sisting of  three  22§  volt  units.  $1-12.50. 

The  Old  Way:  The  price  of  Radiola  V  or 
Radiola  RC  when  equipped  for  storage  bat- 
tery operation,  formerly  came  to  $207.50. 

Send  for  this  Free  Booklet 

There  are  Radiolas  from  $25  to  $350.  Send  for 
the  booklet  that  describes  them  all. 


BEG.  U.S.  PAT.  OFF. 


Radio  Corporation  of  America 


R.  F.  D. 


RADIO  CORP.  OF  AMERICA 
Dept.  2066.  233  Broadway,  New  York 

Please  send  me  your  free  Radio  Booklet. 

Name 


Street  Address 
CitT 


Tested  and  approved  by  Radio  Broadcast  ^ 


New 


Equipment 


A  SOCKET  FOR  THE  WD- J  I 
SVt!lS;gafiSd\t  Alden  Mfg.  Co.  of  52  Wi,- 
base  that  malfes  the  sStVe       ^  with  a  s"b" 
spnng  contactors  arearran  Jh?  Subf  antH  and  the 
nect,on  with  the  5b?$5^^*l*V«&. 

cen™  The  pnce  is  75 


THE  MUSIC  MASTER 

model  has  r,Sch  hnalr-    The  home 
feo.    General   RadS  f  "  and-se,,s  for 
Market  St^V&S!^'  *4 


k  th    f      ,     ™E  SONOCHORDE 
Is  the  first  loud  sDeal^r  ♦ 

gutta-percha.  It  T^J^?*  witfl.  a  horn  of 
field-exciting  current  f  ?  ;*°J  Uje  wth°"t  any 
strument,  made  hy -  j^  a  quahty  in^ 

Beach  St.,  Revere,  Mass .  "  79 


THE  PACENT  RHEOSTAT 
's  mechanically  and  e/Prtr,v,ii 
appearance  is  in  keeping w  h  S  g°°-d  and  its 
quahty  receiving  equ ?L™ for*  °h  ?^b*&" 
"eennnade.    ft«    ?  g  has 

New  York  City  k  PL' 


RADIO  BROADCAST  ADVERTISER 


^}%e  famous  FAD  A  ONE  SiXTY^^eNEUTRQDYNE  circuit^ 
Neutrodyne 

is  the  name  given  to  a  marvelous  new  radio  receiver  circuit  invented 
by  Professor  L.  A.  Hazeltine  of  Stevens  Institute  of  Technology, 
Hoboken,  N.  J.  and  used  in  the  FADA  "ONE  SIXTY"  receiver. 

Only  four  vacuum  tubes  are  used.  The  selectivity  is  remarkable 
and  yet  the  dials  can  be  adjusted  to  receive  distant  stations  with 
great  ease. 

The  FADA  "ONE  SIXTY"  will  receive  broadcasted  concerts  from  the 
Atlantic  to  the  Pacific  and  with  loud  speaker  intensity. 

Denver,  Colo.,  San  Antonio,  Tex.,  Havana,  Cuba  and  Los  Angeles,  Calif, 
are  some  of  the  far  distant  stations  listened  to  from  New  York  City. 

The  FADA  "ONE  SIXTY"  is  the  ideal  receiver— the  cost  $120.00. 
F.  A.  D.  ANDREA    1581-B  Jerome  Ave.  New  York  City 

FADA  "ONE  SIXTY" 

-with  the  NEUTRODYNE  circuit  ~ 


-jt  Tested  and  approved  by  Radio  Broadcast  -fa 


RADIO  BROADCAST  ADVERTISER 


oiodrm  * 

"Built  First  to  Last" 

This  little  beauty  was  approved 
by  our  engineers  only  when 
convinced*  that  they  had  pro- 
duced t  he  one  socket  that  com- 
bines  all  the  essential  features 
of  a  good  socket. 

1.  Positive  Cotogrip  Contacts 

2.  Hard  Rubber  Insulation. 

3.  Rugged  Construction. 
4-  Compact  Design. 
5.  Concealed  Mounting. 

It  is  impossible  to  show  the 
unique  mechanical  action 
of  Cotogrip  contacts  in  a 
photograph.  It  is  different 
from  any  other  socket  you 
have  ever  seen.  This 
socket  will  interest  you  in 
every  way. 

You  ought  to  have  one. 
Ask  Your  Dealer 


TYPE  ' 


TUBE  S<- 


COTO-COILCO.  PROVIDENCE 


WHY    METRO    HEADPHONES   ARE  SUPERIOR 


Actuating 
Coil  Cores 


1\/J"ETR0  HEADPHONES 
faithfully  reproduce 
every  sound  variation  so  that 
reception  is  alwavs  clear  and 
natural.  The  magnetic  cur. 
rent  which  operates  the  dia- 
phragm is  transmitted  by  the 
actuating  coils  through  the 
soft  Armco  Iron  Cores,  whi 
allow  a  ready  change  of  mag 
netic  strength. 

H  is  this  remarkable  ability 
of  the  actuating  coil  cores  to 
react  faithfully  to  every  mag- 
net impulse  that  helps  to  pro- 
duce Metro  sensitivity.  A  small 
detail,  but  perfection  is  made 
up  of  such  details.  Insist  up- 
on Metro  Headphones  because 
you  can  be  sure  that  every 
detail  is  as  it  should  be. 


Little  Giant  Receiving  Set 

A  surprisingly  compact  set. 
Simplest,  tuning  device.  Com- 
plete with  Metro  Head-  $14  oo 


Metro  Waye  Selector 

Makes  any  set  highly  selective 
Completely  separates  «7  Cft 
360  from  400  meters.  ...  » •  •3U 


METRO  ELECTRICAL  CO.,  Inc 

«7  nui  fac*UTers  °f  Metropolitan  Radio  Products 

67  Gob,e  Street  Newark,  N.  J 

*  Tested  and  approved  by  Radio  Broadcast  * 


RADIO  BROADCAST  ADVERTISER 


J^O  loud  speaker 
is  perfect,  un- 
less it  can  be  ad- 
justed to  your  own 
individual  set. 
The  Atlas  Ampli- 
tone  is  adjustable 
to  any  set.  Com- 
plete with  con- 
necting cord 

$25.00 


A  Real 

Musical 

Instrument 

ACTUAL  re-PRODUCTION,  of  the  ar- 
tist's music  as  broadcasted,  is  at  last  attained 
in  the  Atlas  Amplitone  Loud  Speaker,  with- 
out blast  or  distortion.  The  artist's  person- 
ality breathes  again  in  the  full,  natural,  vi- 
brant tones  of  the  Amplitone  Re-PRODUC- 
TION. Musical  critics  and  radio  fans,  who 
have  heard  the  Amplitone,  agree  that,  at  last, 
the  musical  superiority  of  even  the  finest 
phonographs  has  been  surpassed. 

Embodies  exclusive  acoustic  principles  in- 
cluding the  marvelous  double  diaphragm. 

Adds 
AMPLITONE 

LOUD  SPEAKER 


^    *  * 

The  Atlas  Amplitone  Unit, 
(without  base  or  horn),  with 
Grafonola  Attachment,  for  use 
with  your  own  horn  or  base,  or 
to  convert  any  phonograph  (ex- 
cept the  Brunswick)  into  a  loud 
speaker. 

$13.50 


Write  for  illustrated  booklet 
and  the  name  of  your  nearest 
Amplitone  dealer.  No  other 
loud  speaker  can  take  the  place 
of  the  Amplitone. 


Multiple  Electric  Products  Company 


5  Orange  Street 


Newark,  N.  J. 


RADIO  BROADCAST  ADVERTISER 


New  "UNITED"  Vernier 

A  Miracle-Worker  In  Fine, 
Selective  Tuning.  Oper- 
ates on  a  New  Principle. 

Will  bring  in  the  elusive  stations  that  have 
thus  far  defied  you,  by  giving  at  least  twice 
as  fine  a  tuning  as  has  ever  been  possible 


VERNIER  PLATES 


CONTACT  RING 


SCREW  THREAD 
FOR  OPERATING 
VERNIER 


MICA  DISC 
BETWEEN 
PLATES 


CHUCK  FOR 
CLAMPING  DIAL 
TO  SHAFT 


with  the  best  condensers  thus  far  developed. 

Can  be  attached  to  any  plate  condenser,  by  drilling 
one  hole  in  top  plate.    Price,  each  Postpaid  $2.50. 

"UNITED"  VARIABLE  CONDENSERS  WITH  NEW  VERNIER 

43-plate™each  $6.50     23-plate— each  $6.00 
11-plate— each  $5.50 

"UNITED"  TRANSFORMER 

Audio  Frequency.  Amplifies  detected  signals  so  they  come  in  clear  and 
strong,  for  either  headphone  or  loudspeaker  reception.     Each  $4.50. 

Send  for  catalogue  of  United  Products 

UNITED  MFG.  &  DISTRIBUTING  CO. 

536  Lake  Shore  Drive  CHICAGO,  ILL. 

New  York  Office  San  Francisco  Office 

50  Church  St.,  New  York,  N.  Y.  709  Mission  St.,  San  Francisco,  Cal. 


CHARGE 

YOUR 

BATTERY 

WHILE 

YOU 

SLEEP 

Hook  the  Leich 
NON  TUNE  Rectifier 
to  your  battery  after 
the  evening's  enter- 
tainment and  let  it 
charge  all  night — no 
clanger — you  needn't 
watch  it. 


Its  2  ampere  charging  rate  is  sufficient  for  home  use  when 
three  or  four  5 -watt  tubes  are  operated. 

With  the  increased  use  of  quarter  ampere  tubes  the  NON 
TUNE  Rectifier  will  soon  be  in  a  class  by  itself ;  because  of 
its  high  efficiency  it  uses  less  than  40  watts  of  current  at 
full  load. 

NON  TONE  FEATURE  gives  this  charger  flexibility  in  its 
operation,  allowing  for  considerable  voltage  and  frequency 
variation  of  the  power  circuit. 

A  PATENTED  RELAY  LOCK  keeps  the  battery  circuit 
open  when  the  power  current  fails. 

LEADING  RAILROAD  COMPANIES  have  used  NON 
TUNE  Rectifiers  for  years. 

Try  a  NON  TUNE.  Ask  your  dealer  or  write  for  Bulletin 
100-A. 

LEICH  ELECTRIC  CO.,  Mfrs.,  Genoa,  111. 

Non  Tune  Rectifiers — Leich  comfortable  headphones 


DANIEL  BOONE 

Wilderness  Scout 
by  Stewart  Edward  White 
An  out  of-doors  story  for  fathers  and  sons 
At  bookstores,  $1.75 

Doubleday,  Page  £s  Co. 


Tune  In  To 
WDAP 

— the  powerful  broadcasting  station  at 


Lake  Shore  Drive  and  Upper  Michigan  Avenue 
CHICAGO 


From  Porto  Rico  to  lonely  ranches  in  Alberta  and 
Saskatchewan,  from  sunny  San  Diego  to  Quebec,  and  even 
a  thousand  miles  out  in  the  Atlantic  and  Pacific  oceans, 
programs  from  THE  DRAKE  are  picked  up.  You'll  be  par- 
ticularly well  repaid  by  tuning  in  Tuesday,  Thursday,-  Sat- 
urday, and  Sunday  evenings — concerts  include  selections  by 
THE  DRAKE  Ensemble  Orchestra. 

WDAP  Station  is  but  a  single  interesting  feature  of 
THE  DRAKE,  Chicago's  finest  hotel.  When  in  Chicago  be 
sure  to  stop  at  THE  DRAKE.  See  how  concerts  are 
broadcasted,  and  enjoy  the  world  famous  service  and  sur- 
roundings of  this  wonderful  hotel.    Information  on  request. 

Under  The  Blackstone  Management,  the  world's  stand- 
ard in  hotel  service. 


Tested  and  approved  by  Radio  Broadcast 


RADIO  BROADCAST  ADVERTISER 


9  99 


(Socket  and  Rheostat) 


"Having  time  of  my  life  getting  most 
splendid  results  from  the  'Socostat 
says  one  radio  fan 

I  ^HE  "Socostat"  is  a  combination  of 
socket  and  rheostat  that  eliminates  the 
wiring  of  two  separate  parts.  Saves  time, 
material  and  money. 


Single-unit  socket  and  Rheostat 
foi  Table  or  Panel  Mounting 


No  exposed  wires.  The  internal  rheostat 
permits  very  sensitive  filament  adjust- 
ment. Tube  noises  reduced  to  a  minimum.  Bakelite  base 
and  cover.  Nickel  plated  receptacle  takes  any  standard  de- 
tector and  amplifier  tube.     Rings  and  screws  all  nickel 

plated.   The  "Socostat"  simplifies  your 


POTT 


View  showing  panel  mounting  of 
"Socostat" 


construction  and  improves  the  appear- 
ance and  operation  of  your  set.  Guar- 
antees a  smooth  and  positive  contact. 

We  guarantee  that  you  will  be  satisfied. 

Price  $2.50  at  your  dealer  or  write. 


Another  radio  expert  writes: 
"The  'Socostat'  practically  eli- 
minates the  usual  tube  noises  and 
gives  .better  results  than  the  soc- 
ket and  rheostat  in  every  way. 
Have  shown  it  to  several  of  the 
boys  and  all  agree  that  it  is  O.  K. 
It  should  go  big  with  the  Radio 
Bugs." 


FEDDERS  MANUFACTURING  CO.,  INC. 

59  Tonawanda  Street  Buffalo,  N.  Y. 


View  showing  cover  and  ring  removed. 


RADIO  BROADCAST  ADVERTISER 


RADIO  ADVANCES  and 

LUDWIG  HOMMEL  &  CO.  DEALERS  WITH  IT 


DISTRIBUTORS  FOR 
Radio  Corpoca*t«n  of  America 

Westinghoui^  ^Jdeneral  Electric 
Acme         Atwater  Kent  Baldwin 
Brach       Brandes  Burgess 
Chebea  Clapp-Eastham 
Cunningham  Cutler-Hammer 
Dubilier  Fada  Fahnestock 

Formica     Frost    General  Radio 
Hipco        Homecharger  Hopewell 
Kellogg    Kennedy  Klosner 
Murdock    Omnigraph  Pacent 
Radio  Service  Radial)  (Ampetite) 

Remler     Rhamstine  Tuska 
Western  Electric 
and  other  Leading  Manuf; 


Established  radio  dealers  will  recall  the  hectic  days  of  last  spring  when 
any  radio  material  could  be  sold  and  standard  makes  were  at  a  premium. 

Radio  has  become  more  stabilized,  and  crude  material  has  given 
way  to  perfected  apparatus.    Your  trade  will  want  the  newest  and 
best  in  Radio.    Can  you  satisfy  the  demand  for: 
Vernier  Condensers 
Vernier  Rheostats 

Vernier  Adjusters  for  Variometers 
WD-11  Socket  Adapters 
Coupled  Circuit  Tuners 
Radio  Frequency  Sets 

Console  Type  Dry  Cell  Tube  Sets 
Power  Amplifier  Loud  Speakers 
Ludwig  Hommel  &  Co.  dealers  have  these  items  illustrated  in 
Hommel's  Encyclopedia  of  Radio  Apparatus  and  are  kept  in  touch 
with  all  developments  in  the  art. 

It  pays  to  tie  up  with  a  jobber  who  wholesales  exclusively 
and  gives  his  dealers  100%  service. 

Send  your  next  order  to  Hommel's  and  ask  for  our  new 
Illustrated  Encyclopedia  225  B.    It's  free  to  dealers. 


530-534-  FERNANDO  ST. 


PITTSBURGH,PENNA 


Na-ald  Special 
Socket 
No.  499 


Na-ald  De  Luxe, 
No.  400 


It 's  the  contact 
that  counts 

The  Na-ald  Special  Socket  No. 
499  is  a  sturdy  little  socket  for 
the  G.  E.  No.  199  dry  cell  tube. 
It  has  special  slot  construction, 
is  moulded  from  genuine  Bake- 
lite,  and  because  of  thorough  cure  and 
high  dielectric  properties  it  keeps 
plate  to  grid  losses  at  a  minimum  (of 
particular  importance  in  Flewelling 
Circuit,  or  in  Radio  Frequency). 


The  Na-ald  De  Luxe  V.  T.  Socket  is 
of  highest  quality  throughout.  Its 
laminated  phosphor  bronze  strips  press 
firmly  with  a  side  wipe  action  on  the 
contact  pins,  keeping  surface  clean 
and  insuring  perfect  contact. 

Send  stamp  for  dial,  small-space  socket, 
condenser  and  R.F.  transformer  circulars 
These  sockets  retail 
at  75c.  each 

ALDEN  MANUFACTURING  CO. 

formerly  Alden-Napier  Co. 
Dept.  B.  52  Willow  St.,  Springfield,  Mass. 


Booklet  with  wiring  design  instructions  for 
Hazeltine's  Neutrodgne  and  the  Flewelling 
Super- regenerative  Circuits,  and  a  number 
of  standard  circuits,  packed  with  eachsocket. 


"Circuits  of  Victory" 

By  A.  Lincoln  Lavine 

$3.00  at  your  bookstore 
Doubleday,  Page  &  Co.,    Garden  City,  N.  Y. 


FREE 

CATALOGUE 

Make  D  X  Records 
With  D  X  Supplies 

This  Catalogue  should  be  called  "Recipes  for 
Long  Distance."  It  was  written  to  help  ama- 
teurs pull  in  the  most  distant  stations. 

To  Get  Your  Copy 
Write  Department  1471 

D-X  Radio  Company 

123  Liberty  St.  New  York  City 


it  Tested  and  approved  by  Radio  Broadcast  it 


RADIO  BROADCAST  ADVERTISER 


14-inch  Amplifier 
complete,  $30 

21-inch  Amplifier 
complete*  $35 


JOBBERS- 
DEALERS  — 

A  MUSIC  MASTER  will  be 
sent  to  you  with  full  privilege 
of  return.  Write  for  full  de- 
scription of  the  GERACO 
line,  and  prices. 


USIC 
ASTER 


AMPLIFIER 

m 


Rich  Resonance  that 
Onlu  WOOD  Can  Give 


THEY  call  MUSIC  MASTER  the  "Stradivarius  Among  Ampli- 
fiers." For  its  horn  is  WOOD,  with  that  pure,  mellow-sweet 
tonal  quality  of  the  human  voice  that  wood  alone  can  simulate. 
(Phonograph  experts  proved  the  principle  before  radio.) 

A  powerful  amplifying  unit  in  the  art-metal  base  ot  MUSIC  MASTER  sends 
sounds  up  through  a  cast-aluminum  "gooseneck" — cast-aluminum,  so  it  won't 
vibrate.  This  conveys  true  tones  to  the  wooden  horn,  where  they  are  beauti- 
fully enriched,  humanized  and  given  to  the  audience  as  they  are  actually  sung, 
played  or  spoken. 

There  is  only  one  MUSIC  MASTER:  Get  it  and  you  won't  regret  it!  Hun- 
dreds of  orders  are  pouring  in  daily.  Demand  actually  exceeds  supply,  so  get 
your  order  in  NOW!  Comes  complete,  ready  to  attach  in  place  of  head  'oliones. 
No  extras  to  buy.  Hear  MUSIC  MASTER  at  your  dealer's  to-day.  COM- 
PARE it  with  any  other  amplifier,  regardless  of  price!    Literature  on  request. 


Ask  about  the  GERACO  Phonograph  attachment  which  makes  an 
efficient  radio  loud-speaker  of  your  Victrola  or  Columbia.  Only  $10. 


GENERAL    RADIO  CORPORATION 

Makers  and  Distributors  of  Hiqh-Grade  Radio  Apparatus 

Walter  L.  Eckhardt,  President 

CHICAGO  624-628  Market  St.,  PHILADELPHIA  PITTSBURGH 


* 


■jt  Tested  and  approved  by  Radio  Broadcast  if 


RADIO  BROADCAST  ADVERTISER 


ECHOPHONE 

Regenerative    Radio  Equipment 


'  ^_  ■.        .  .        ;,  ' 


Licensed  under  Armstrong  Patent  Nc 


,149 


The  Lowest  Priced  GOOD  Radio  Set  on  the  Market 


THE  latest  word  in  radio  development.  Made  in  various  types.  It  has  proved  re- 
sults in  long-distance  reception.  Has  unusual  ease  of  operation  for  the  beginner. 
Can  be  used  with  headphones  or  loud-speaker.  Made  by  the  Radio  Shop  of  St.  Louis, 
Mo.,  and  Sunnyvale,  Cal.,  having  10  years'  experience  in  making  dependable  radio  sets 
on  sound  engineering  principles. 


Prices  Range  from 
$70  to  $160 


ECHOPHONE  CORPORATION 

1922-28  Chestnut  St.  St.  Louis,  Mo. 


RADIO    LOUD  SPEAKER 

for  Phonographs 

The  MORRISON  Loud  Speaking  Unit,  for  use  on  phonographs,  takes 
the  place  of  awkward  headsets.  Possesses  a  tone  value  100% true — an 
achievement  never  before  attained  in  a  loud  speaker. 

Attaches  in  Place  of  Reproducer 

Slips  on  tone-arm  of  phonograph  in  place  of  reproducer,  or  can  be 
used  with  horn.  Adapted  to  any  bulb  set  with  one  or  more  stages 
of  amplification.  Adjustable  from  soft  to  loud  tone.  Cannot  possibly 
rattle  or  loosen  through  excessive  amplification.  A  popular-priced 
Loud  Speaker  that  compares  with  most  expensive  instruments  on 
the  market.  Thousands  in  use  giving  perfect  satisfaction.  Hand- 
somely nickel  plated,  complete  with  5  ft.  cord,  $10 — at  your  dealer's 
or  direct.  Sent  C.  0.  D.,  if  desired.  Fully  guaranteed.  Money 
back  if  not  satisfied.  (When  ordering,  specify  make  of  phonograph). 

MORRISON  LABORATORIES,  Inc. 

Dept.  10,  536  Griswold  St.      Detroit,  Michigan 


Increase  the  Efficiency  of  Your  Set  With  a 

★PROUDFOOT  VERNIER  CONDENSER 
Special  Features 
Plates  Cannot  Short  Fool  Proof 

No  Adjustments  to  Get  Out  of  Order 
Two  Dials  But  Only  One  Knob — one  dial  to  indicate 
position  of  group  plates  and  one  to  show  relationship  of  vernier 
to  group  plates. 

Higher  Efficiency — the  vernier  plate  being  one  of  the 
group  plates,  allows  the  vernier  ad- 
justment without  the  additional 
electrical  losses  due  to  the  usual  con- 
struction of  the  vernier  being  separ- 
ated from  the  main  plates. 

Style    M.  F.  Cap  Price 
11  plate       .000^5  $5.00 
21    "         .00055  6.00 
43    "         .0011  7,00 
CRUVER  MFG.  COMPANY 
2456  W.  Jackson  Blvd.      Chicago,  III. 


The  most  satisfactory  book  for  beginners 
that  has  yet  appeared. — Public  Ledger. 

RADIO 
SIMPLIFIED 

By  KENDALL  &  KOEHLER 
Radio  Instructors 

WHAT  TO  BUY 
HOW  TO  BUILD 
HOW  TO  OPERATE 

A  clear  explanation  of  Radio  in  sim- 
ple language  with  complete  direc- 
tions lor  assembling  and  installing 
home  radio  equipment.  Will  aid  you 
in  getting  the  best  results  Irom  your  set. 
96  Illustrations  including  picture  diagrams  show- 
ing hook-ups,  etc.  Cloth,  250  pages,  $1.00. 
On  sale  at  Booksellers  or  mailed  on  receipt  of  price 
THE  JOHN  C.  WINSTON  CO.,34Winston  Bldg.,  Philadelphia,  Pa. 


•Jt  Tested  and  approved  by  Radio  Broadcast 


V 


An  Improved  RHEOSTAT  ^ 
another  P  A  C  E  N  T  development 

SIMPLE— STURDY— FINELY  ADJUSTABLE— EASY  TO  MOUNT 


You'll  welcome  the  many  advantages  in  the 
new  PACENT  RHEOSTAT.  It  is  beauti- 
fully constructed,  flawless  in  performance,  the 
simplest  to  assemble  or  take  apart  when 
mounting.  The  turn  of  one  screw  separates 
the  two  units  (as  illustrated).  Unit  1  consists 
of  the  pointer,  knob  and  shaft  moulded  in  one 
piece.  Unit  2  remains  intact  when  rheostat  is 
separated,  permitting  the  careful  contact  ad- 
justment made  at  factory  to  remain  undis- 
turbed. Changing  from  panel  to  table  mount- 


ing is  simply  a  matter  of  a  few  seconds.  The 
wire  element  will  safely  carry  li  Amp.  contin- 
uously. The  base  of  the  rheostat  is  heat-resist- 
ing and  will  not  crack  or  warp.  The  rheostat 
turns  with  the  smooth  "velvety"  feel  of  preci- 
sion instruments,  making  perfect  control  easy. 
Another  instance  of  PACENT  quality  at 
reasonable  cost. 

The  PACENT  Potentiometer  (same  size  and 

incorporating  all  of  the  advantages  of  the  PACENT 
rheostat)  Catalogue  No.  88,  $1.25. 


Write  for  Descriptive  Bulletin  B-5 

"DON'T  IMPROVISE  PACENTIZE" 

PACENT  ELECTRIC  COMPANY 

INCORPORATED 

Executive  Offices:  22  Park  Place,  New  York,  N.  Y. 


SALES  OFFICES 


Chicago 
Philadelphia 
San  Francisco 


Washington,  D.  C. 
Minneapolis 
St.  Louis 


Canadian  and  British  Licensees: 
Colonial   Radio,    Ltd.,   Hamilton,  Can. 

Members,     Radio    Section,  Associated 
Mfrs.  of  Electrical  Supplies 


Tested  and  approved  by  Radio  Broadcast 


XX  Grade 
is  ri^ht 
far:. 


Kjasier  to  pick  em 

vOith  ^roper  Panels  / 

Program-choosing  demands  delicate  tuning  and  your  radio  panel 
must  be  right  if  you  want  to  get  and  keep  a  station  without  variations 
and  interferences.    For  panels,  bases  and  partitions,  no  other  material 

★ is  more  satisfactory  than  tough,   unchanging,  handsome  Bakelite- 
Dilecto,  XX  grade 

[A Laminated  Phenolic  Condensation  Product^] 

Where  protection  of  lives,  homes,  ships,  cities  and  national  safety 
depend  on  Radio,  Bakelite-Dilecto  panels  are  found  in  use. 

Bakelite-Dilecto  resists  heat,  water,  steam,  oils,  solvents  and  the 
milder  acids.  Cannot  warp  or  swell.  Made  in  sheets,  rods,  tubes  and 
special  shapes  in  black  and  brown  for  all  insulation  requirements. 

Accepting  the  next  best  thing  to  Bakelite-Dilecto  will  not  do  if  you 
seek  highest  radio  results.  Any  electrical  dealer  can  get  it  cut  and 
drilled  to  size  for  you.  Write  us  direct  for  complete  story  of  wonder- 
ful Bakelite-Dilecto. 

Jhe  Continental  Fibre  Company 


if  Tested  and  approved  by  Radio  Broadcast  if 


THE  COUNTRY  LIFE   PRESS.  GARDEN  CITY.  NEW  YORK 


■ 


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